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Background: Levodopa-entacapone-carbidopa intestinal gel (LECIG) infusion was introduced to the Swedish market in 2019 for Parkinson's disease (PD) with motor fluctuations. Long-term data are lacking., Objectives: To study long-term data on LECIG treatment., Methods: A retrospective analysis of the first 24 patients receiving LECIG in Sweden from 2019 to 2023., Results: Five of 24 (21%) patients discontinued LECIG because of side effects, mostly diarrhea. Eight of the 24 (33%) patients died while receiving LECIG. Eleven of 24 (46%) patients were still on LECIG. Median (range) for disease and treatment duration was 19 (9-30) and 3.6 (3.1-4.0) years, respectively, whereas health-related quality of life scales showed median (interquartile range; n) Parkinson's Disease Questionnaire 8-item summary index scores of 38 (4; n = 7), EuroQol 5D scores of 0.59 (0.17; n = 7), and EQ-5D visual analogue scale scores of 65 (10; n = 7)., Conclusions: LECIG infusion is a viable treatment option for PD patients with motor fluctuations, for up to 4 years in our cohort., (© 2024 The Author(s). Movement Disorders Clinical Practice published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

A sustainable HPTLC-densitometric method was developed for quantitative determination of Quetiapine (QUET), Levodopa (LD) and Carbidopa (CD) in presence of Dopamine (DOP) as an internal standard. This applicable technique was achieved by spiking human plasma and extraction was performed using the protein precipitation approach. The mobile phase used was acetone, dichloromethane, n-butanol, glacial acetic acid and water (3: 2.5: 2: 2: 1.75, by volume). Method validation was done according to US-FDA guidelines and was able to quantify Quetiapine, Levodopa and Carbidopa in the ranges of 100-4000, 200-8000 and 30-1300 ng/mL, respectively. Bioanalytical method validation parameters were assessed for the studied drugs. Finally, the analytical suggested methodology was evaluated using various green and white analytical chemistry metrics and other tools, such as the green solvent selection tool, analytical eco-scale, green analytical procedure index, analytical greenness metric approach and the red-green-blue algorithm tool. The results revealed that the applied analytical method had a minor impact on the environment and is a relatively greener option than other previously reported chromatographic methods., (© 2024. The Author(s).)

Background: Proton pump inhibitors (PPIs), which inhibit gastric acid secretion, are frequently prescribed to patients with Parkinson's disease (PD). Levodopa, the gold-standard treatment for PD, demonstrates enhanced solubility in acidic environments. Although PPIs increase gastric pH and may affect levodopa absorption, the effect of concomitant PPI use on levodopa pharmacokinetics in patients with PD remains unknown. This study aimed to investigate the effect of the concomitant use of esomeprazole, a PPI, on the pharmacokinetics of levodopa and carbidopa and clinical symptoms in patients with PD., Methods: We prospectively enrolled 40 patients with PD and compared the pharmacokinetics of levodopa and carbidopa and clinical symptoms before and two weeks after the concomitant use of esomeprazole., Results: The plasma concentrations of levodopa 30 min after concomitant oral administration of levodopa and esomeprazole were significantly lower (4.92 ± 4.10 μmol/L) than those without concomitant esomeprazole use (6.26 ± 3.75 μmol/L; p = 0.027). The plasma concentrations of carbidopa showed no significant differences with respect to concomitant esomeprazole use. Significant elevation was recorded in all subscores of the Movement Disorder Society-sponsored revision of the Unified Parkinson's disease Rating Scale scores after concomitant use of esomeprazole. No significant differences were observed between Helicobacter pylori-negative and Helicobacter pylori-positive patients. Non-elderly patients (age ≤ 70 years) tended to be more susceptible to the effect of esomeprazole on levodopa pharmacokinetics and clinical symptoms., Conclusions: The unnecessary use of PPIs should be avoided in patients with PD, especially in non-elderly patients, to improve absorption of levodopa., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Rapid control of the content of Parkinson's drugs in biological fluids and pharmaceutical formulations is of great importance because changes in the concentration of these drugs affect their bioavailability and biopharmaceutical properties. Therefore, we presented a simple and convenient method for the ratiometric detection of carbidopa and levodopa for carbon dots (CDs) dual-fluorescent emission. Dual-emission CDs were prepared from chitosan using a microwave method, following which the surface was chemically modified with terephthalaldehyde. CDs had two strong well-separated peaks at 445 and 510 nm. The relative measurement of carbidopa and levodopa was based on the static extinction of CDs at 445 nm and increase at 510 nm, respectively. The linear range for carbidopa measurement was 2.5-300 nM, with a limit of detection (LOD) of 2.1 nM, and a relative standard deviation (RSD) of 1.68%. Further, the linear range for levodopa measurement was equal to 3.0-400 nM, with LOD and RSD% of 2.8 nM and 3.5%, respectively. Also, selectivity of ratiometric sensor in the presence of interferences was investigated, which showed that the recovery of carbidopa and levodopa in serum and urine samples has changed between 96.80% and 116.24% with RSD% 0.11-0.77. CDs also provided good results for the determination of carbidopa and levodopa in real samples, and had high selectivity in the presence of possible interferences., (© 2024 International Union of Biochemistry and Molecular Biology, Inc.)

Background: It has been suggested that carbidopa at high blood concentrations may counter the therapeutic effect of levodopa in Parkinson's disease by entering the brain and blocking central levodopa conversion to dopamine. We previously demonstrated equivalent plasma levodopa concentration in patients with Parkinson's disease during 16 h of (1) intravenous carbidopa/levodopa (DIZ101) infusion, (2) subcutaneous carbidopa/levodopa (DIZ102) infusion or (3) intestinal carbidopa/levodopa gel infusion. Plasma levels of carbidopa were however approximately four times higher with DIZ101 and DIZ102 than with LCIG, and higher than those usually observed with oral levodopa/carbidopa., Objectives: To investigate if high carbidopa blood concentrations obtained with parenteral levodopa/carbidopa (ratio 8:1) counter the effect of levodopa on motor symptoms., Methods: Eighteen patients with advanced Parkinson's disease were administered DIZ101, DIZ102, and intestinal levodopa/carbidopa gel for 16 h on different days in randomized order. Video recordings of a subset of the motor examination in the Unified Parkinson's Disease Rating Scale (UPDRS) were evaluated by raters blinded for treatment and time. Motor function was also measured using a wrist-worn device monitoring bradykinesia, dyskinesia, and tremor (Parkinson KinetiGraph)., Results: There was no tendency for poorer levodopa effect with DIZ101 or DIZ102 as compared to LCIG., Conclusion: Although DIZ101 or DIZ102 causes approximately four times higher plasma carbidopa levels than LCIG, patients responded equally well to all treatments. The results do not indicate that high plasma carbidopa levels hamper the motor efficacy of levodopa., (© 2024 The Author(s). Movement Disorders Clinical Practice published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

Hyperinsulinism due to focal or diffuse pancreatic lesions causing recurrent episodes of hypoglycemia is rare in mid-childhood. There is no consensus on the gold-standard imaging method to diagnose focal insulin-producing lesions beyond infancy. A 14-year-old boy with a complex medical history and refractory epilepsy, presented with blood glucose (BG) of 52 mg/dL (2.9 mmol/L) (normal reference range: 70-100 mg/dL [3.9-5.6 mmol/L]) and increased seizure frequency. He failed a fast within 4 hours, with BG of 48 mg/dL (2.7 mmol/L) and insulin level of 4.6 µIU/mL (24.6 pmol/L) (diagnostic at the time of hypoglycemia >1.25 μU/mL [8.7 pmol/L]). Conventional imaging studies showed no pancreatic lesion. Fluorine-18-L-dihydroxyphenylalanine positron emission tomography/magnetic resonance imaging ( 18 F-DOPA-PET/MRI) scan premedicated with carbidopa demonstrated intense focal 18 F-DOPA uptake in the distal pancreatic tail. He underwent distal pancreatectomy. Histopathology showed focal pancreatic islet cell hyperplasia, with more than 90% of the neuroendocrine islet cells being positive for chromogranin and synaptophysin, with no loss of p57 staining. Genetic studies were negative for mutations in ABCC8 , KCNJ11 , GCK , or GLUD1 genes, multiple endocrine neoplasia (MEN) type 1, and Beckwith-Wiedemann syndrome. BG normalized after surgery. Seizure frequency improved. This case highlights the utility of 18 F-DOPA PET/MRI imaging in diagnosing focal hyperinsulinism beyond infancy., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

In the 1980s, Orion Pharma, then a mid-ranking Nordic area pharmaceutical company, established a drug development programme on the inhibition of catechol O-methyltransferase (COMT). This enzyme, which plays an important role in the inactivation of catecholamine neurotransmitters and drugs with a catechol structure, thus came under consideration as a target in the innovative translational and clinical programme we describe in this historical review. The starting point was the conjecture that a peripherally acting COMT inhibitor might improve entry of levodopa into the brain. This had potentially significant implications for the medical treatment of Parkinson's disease (PD). The rationale was that more efficient delivery of levodopa to the brain might allow the high therapeutic doses of levodopa to be reduced and the dose interval to be extended. Elucidation of structure-activity relations paved the way for the discovery and development of entacapone, a 5-nitrocatechol that was a potent and highly specific inhibitor of COMT. Experience in phase III clinical trials established that entacapone, used as an adjunct to regular or controlled-release levodopa preparations (also including a peripherally acting dopa-decarboxylase inhibitor), increased ON-time and reduced OFF-time and improved clinical condition in patients with PD experiencing wearing-off, often with a reduced daily levodopa dose. Several of these studies also identified that entacapone improved patients' quality of life and was cost-effective. Subsequently, entacapone has been amalgamated into a triple-combination preparation (Stalevo®) with levodopa and carbidopa to create a flexible and convenient drug therapy for patients with PD who have end-of-dose motor fluctuations not stabilised on levodopa/dopa-decarboxylase inhibitor treatment. This review offers a historical perspective on a successful programme of drug development by researchers who played central roles in the progress from exploratory hypothesis to registered pharmaceutical product., (© 2024. The Author(s).)

Carbidopa and levodopa remain the established therapeutic standard for managing Parkinson's disease. Nevertheless, their oral administration is hindered by rapid enzymatic degradation and gastrointestinal issues, limiting their efficacy, and necessitating alternative delivery methods. This work presents a novel strategy employing dissolving microarray patches (MAPs) loaded with carbidopa and levodopa, formulated with Tween® 80 to improve their transdermal delivery. The fabricated MAPs demonstrated an acceptable mechanical strength, resisting pressures equivalent to manual human thumb application (32 N) onto the skin. Additionally, these MAPs exhibited an insertion depth of up to 650 µm into excised neonatal porcine skin. Ex vivo dermatokinetic studies could achieve delivery efficiencies of approximately 53.35 % for levodopa and 40.14 % for carbidopa over 24 h, demonstrating their significant potential in drug delivery. Biocompatibility assessments conducted on human dermal fibroblast cells corroborated acceptable cytocompatibility, confirming the suitability of these MAPs for dermal application. In conclusion, dissolving MAPs incorporating carbidopa and levodopa represent a promising alternative for improving the therapeutic management of Parkinson's disease., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Parkinson's disease is managed using levodopa; however, as Parkinson's disease progresses, patients require increased doses of levodopa, which can cause undesirable side effects. Additionally, the oral bioavailability of levodopa decreases in Parkinson's disease patients due to the increased metabolism of levodopa to dopamine by gut bacteria, Enterococcus faecalis, resulting in decreased neuronal uptake and dopamine formation. Parkinson's disease patients have varying levels of these bacteria. Thus, decreasing bacterial metabolism is a promising therapeutic approach to enhance the bioavailability of levodopa in the brain. In this work, we show that Mito-ortho-HNK, formed by modification of a naturally occurring molecule, honokiol, conjugated to a triphenylphosphonium moiety, mitigates the metabolism of levodopa-alone or combined with carbidopa-to dopamine. Mito-ortho-HNK suppresses the growth of E. faecalis, decreases dopamine levels in the gut, and increases dopamine levels in the brain. Mitigating the gut bacterial metabolism of levodopa as shown here could enhance its efficacy., (© 2024. The Author(s).)

Levodopa (LD) has been the most efficacious medication and the gold standard therapy for Parkinson's disease (PD) for decades. However, its long-term administration is usually associated with motor complications, which are believed to be the result of the fluctuating pharmacokinetics of LD following oral administration. Duodopa ® is the current option to offer a continuous delivery of LD and its decarboxylase inhibitor carbidopa (CD); however, its administration involves invasive surgical procedures, which could potentially lead to lifelong complications, such as infection. Recently, dissolving microarray patches (MAPs) have come to the fore as an alternative that can bypass the oral administration route in a minimally invasive way. This work explored the potential of using dissolving MAPs to deliver LD and CD across the skin. An acidic polymer poly(acrylic acid) (PAA) was used in the MAP fabrication to prevent the potential oxidation of LD at neutral pH. The drug contents of LD and CD in the formulated dissolving MAPs were 1.82 ± 0.24 and 0.47 ± 0.04 mg/patch, respectively. The in vivo pharmacokinetic study using female Sprague-Dawley ® rats (Envigo RMS Holding Corp, Bicester, UK) demonstrated a simultaneous delivery of LD and CD and comparable AUC values between the dissolving MAPs and the oral LD/CD suspension. The relative bioavailability for the dissolving MAPs was calculated to be approximately 37.22%. Accordingly, this work highlights the use of dissolving MAPs as a minimally invasive approach which could potentially bypass the gastrointestinal pathway and deliver both drugs continuously without surgery.

An electroanalytical methodology was developed by direct differential pulse voltammetric (DPV) measurement of Levodopa (LD), Carbidopa (CD) and Entacapone (ENT) mixture using bare glassy carbon electrode (GCE) in Britton Robinson (BR) buffer (pH = 2.0). A multivariate calibration model was then applied to the exported preprocessed voltammetric data using partial least square (PLS) as a chemometric tool. Additionally, the model was cross-validated and the number of latent variables (LVs) were determined to produce a reliable model for simultaneous quantitation of the three drugs either in their synthetic mixtures or in their marketed pharmaceutical formulation with high accuracy and precision. Data preprocessing was used to tackle the problem of lacking bi-linearity which is commonly found in electrochemical data. The proposed chemometric model was able to provide fast and reliable technique for quantitative determination of antiparkinson drugs in their dosage forms. This was successfully achieved by utilizing sixteen mixtures as calibration set and nine mixtures as validation set. The percent recoveries for LD, CD and ENT were found to be 100.05% ± 1.28%, 100.04% ± 0.53% and 99.99% ± 1.25%, respectively. The obtained results of the proposed method were statistically compared to those of a previously reported High Performance Liquid Chromatography (HPLC) methodology. Finally, the presented analytical method strongly supports green analytical chemistry regarding the minimization of potentially dangerous chemicals and solvents, as well as reducing energy utilization and waste generation., (© 2024. The Author(s).)

Levodopa/carbidopa remains the gold standard for treating Parkinson disease (PD), but chronic pulsatile administration contributes to motor complications. This Phase 1 study used a new immediate-release (IR) formulation of carbidopa/levodopa 25/100 mg that is functionally scored for easy and precise splitting to evaluate the effects on levodopa plasma variability when smaller doses are taken more frequently. These functionally scored tablets were shown to be bioequivalent to carbidopa/levodopa 25-/100-mg IR generic reference tablets. Twenty-two healthy volunteers received a whole tablet every 4 hours versus half of the tablet every 2 hours. Plasma levodopa fluctuations were significantly reduced with half-tablets dosed every 2 hours, with a 44% reduction in peaks (P < .0001). While drug exposure did not differ, parameters that underlie motor response variations, including mean peak-to-trough difference and variance, were 51% and 56% less, respectively, with more frequent dosing (both P ≤ .0024). Safety and tolerability of both regimens were similar. In conclusion, more frequent administration of half-tablets of the new functionally scored IR formulation safely provided more constant levodopa levels than whole tablets dosed less often. This tablet technology could facilitate the benefits of more physiologic dopamine replenishment in patients with PD, particularly those with reduced manual dexterity., (© 2024 Avion Pharmaceuticals. Clinical Pharmacology in Drug Development published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

Objective: This study aimed to optimize the formulation of carbidopa/levodopa orally disintegrating tablets (ODTs) in order to improve their disintegration performance, and facilitate easier medication intake for Parkinson's patients., Method: The response surface methodology (RSM) was used to optimize the formulation, with the content of cross-linked polyvinylpyrrolidone (PVPP), microcrystalline cellulose (MCC), and mannitol (MNT) as independent variables, and disintegration time as the response parameter. Python was utilized to model Carr Indices and mixing time to determine the suitable mixing time. Direct compression (DC) was used for the preparation of ODTs., Result: The optimization process resulted in the following values for the independent variables: 7.04% PVPP, 22.02% MCC, and 16.21% MNT. By optimizing the mixing time using Python, it was reduced to 14.19 min. The ODTs prepared using the optimized formulation and a mixing time of 14.19 min exhibited disintegration times of 16.74 s in vitro and 17.63 s in vivo . The content uniformity of levodopa and carbidopa was found to be 100.83% and 99.48%, respectively., Conclusion: The ODTs optimized using RSM and Python demonstrated excellent disintegration performance, leading to a decrease in the time the drug exists in solid form in the oral cavity. This improvement in disintegration time reduced the difficulty of swallowing for patients and enhanced medication compliance, while still ensuring that ODTs prepared by DC had sufficient mechanical strength to meet storage and transportation requirements.

Analysis was conducted to compare levodopa/carbidopa pharmacokinetics and drug-related material in plasma of healthy participants after receiving a continuous infusion of Levodopa/Carbidopa Intestinal Gel (LCIG) to a continuous subcutaneous infusion of foslevodopa/foscarbidopa. Study samples were from a randomized, open-label, 2-period crossover study in 20 healthy participants. Participants received either 24-h foslevodopa/foscarbidopa SC infusion to the abdomen or LCIG delivered for 24 h to the jejunum through a nasogastric tube with jejunal extension. Serial blood samples were collected for PK. Comparability of the LD PK parameters between the two treatment regimens was determined. Selected plasma samples were pooled per treatment group and per time point for metabolite profiling. LC-MS n was performed using high-resolution mass spectrometry to identify drug-related material across the dosing regimens and time points. The LD PK parameter central values and 90% confidence intervals following the foslevodopa/foscarbidopa subcutaneous infusion were between 0.8 and 1.25 relative to the LCIG infusion. With LCIG administration, LD, CD, 3-OMD, DHPA, DOPAC, and vanillacetic acid were identified in plasma at early and late time points (0.75 and 24 h); the metabolic profile after administration of foslevodopa/foscarbidopa demonstrated the same drug-related compounds with the exception of the administered foslevodopa. 3-OMD and vanillacetic acid levels increased over time in both treatment regimens. Relative quantification of LC-MS peak areas showed no major differences in the metabolite profiles. These results indicate that neither the addition of monophosphate prodrug moieties nor SC administration affects the circulating metabolite profile of foslevodopa/foscarbidopa compared to LCIG., (© 2024 Abbvie, Inc. Pharmacology Research & Perspectives published by British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics and John Wiley & Sons Ltd.)

Recent studies have demonstrated that cannabinoids are potentially effective in the treatment of various neurological conditions, and cannabidiol (CBD), one of the most studied compounds, has been proposed as a non-toxic option. However, the adverse effects of CBD on neurodevelopmental processes have rarely been studied in cell culture systems. To better understand CBD's influence on neurodevelopment, we exposed neural progenitor cells (NPCs) to different concentrations of CBD (1 µM, 5 µM, and 10 µM). We assessed the morphology, migration, differentiation, cell death, and gene expression in 2D and 3D bioprinted models to stimulate physiological conditions more effectively. Our results showed that CBD was more toxic at higher concentrations (5 µM and 10 µM) and affected the viability of NPCs than at lower concentrations (1 µM), in both 2D and 3D models. Moreover, our study revealed that higher concentrations of CBD drastically reduced the size of neurospheres and the number of NPCs within neurospheres, impaired the morphology and mobility of neurons and astrocytes after differentiation, and reduced neurite sprouting. Interestingly, we also found that CBD alters cellular metabolism by influencing the expression of glycolytic and β-oxidative enzymes in the early and late stages of metabolic pathways. Therefore, our study demonstrated that higher concentrations of CBD promote important changes in cellular functions that are crucial during CNS development., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: As Parkinson's disease (PD) advances, management is challenged by an increasingly variable and inconsistent response to oral dopaminergic therapy, requiring special considerations by the provider. Continuous 24 h/day subcutaneous infusion of foslevodopa/foscarbidopa (LDp/CDp) provides steady dopaminergic stimulation that can reduce symptom fluctuation., Objective: Our aim is to review the initiation, optimization, and maintenance of LDp/CDp therapy, identify possible challenges, and share potential mitigations., Methods: Review available LDp/CDp clinical trial data for practical considerations regarding the management of patients during LDp/CDp therapy initiation, optimization, and maintenance based on investigator clinical trial experience., Results: LDp/CDp initiation, optimization, and maintenance can be done without hospitalization in the clinic setting. Continuous 24 h/day LDp/CDp infusion can offer more precise symptom control than oral medications, showing improvements in motor fluctuations during both daytime and nighttime hours. Challenges include infusion-site adverse events for which early detection and prompt management may be required, as well as systemic adverse events (eg, hallucinations) that may require adjustment of the infusion rate or other interventions. A learning curve should be anticipated with initiation of therapy, and expectation setting with patients and care partners is key to successful initiation and maintenance of therapy., Conclusion: Continuous subcutaneous infusion of LDp/CDp represents a promising therapeutic option for individuals with PD. Individualized dose optimization during both daytime and nighttime hours, coupled with patient education, and early recognition of certain adverse events (plus their appropriate management) are required for the success of this minimally invasive and highly efficacious therapy., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Anna Jeong is an employee of AbbVie Inc., and may hold AbbVie Inc. stock and/or stock options. Agnita J. W. Boon is a study investigator and has served as an advisory board member for AbbVie Inc., Stada, and Ever Pharma. She has received a research grant from Stichting ParkinsonFonds and the Erasmus Trust Fund. Amy M. Spiegel is an employee of AbbVie Inc., and may hold AbbVie Inc. stock and/or stock options. Arjun Tarakad declarations of interest: none. Eric Freire-Alvarez has received advisory, consulting, and lectures fees from AbbVie Inc., Teva, Bial, Zambon, Esteve, UCB, and Neuraxpharm; and is an investigator on studies funded by AbbVie Inc., Neuroderm, Cerevel, Roche, Anavex, Bial, Zambon, Impax, and Irlab. Enrique Urrea-Mendoza has received advisory/consulting fees from: AbbVie Inc., Defeat MSA USA, and Medtronic. Filip Bergquist has received advisory and lecture fees from AbbVie Inc., GKC, and Britannia; and research support in kind from GKC. He is a board member of Arvid Carlsson Research AB and receives salary from the University of Gothenburg and Sahlgrenska University Hospital. Jason Aldred is a member of the faculty of the University of Washington and Washington State University. He is a study investigator and has received honorarium from AbbVie Inc., Allergan (now AbbVie Inc.), Teva, US WorldMeds, Medtronic, and Abbott. He is an investigator in studies sponsored by AbbVie Inc., Biogen, Acadia, Northwestern University, Neuroderm, Massachusetts General Hospital, and AstraZeneca. He is also a scientific advisor for AbbVie Inc. He has a clinical practice through Selkirk Neurology. Jia Jia is an employee of AbbVie Inc., and may hold AbbVie Inc. stock and/or stock options. Jorge Zamudio is an employee of AbbVie Inc., and may hold AbbVie Inc. stock and/or stock options. Manon Bouchard has received honoraria for consultancy, lectures, and advisory boards from AbbVie Inc., Allergan (now AbbVie Inc.), Merz, Ipsen, Lilly, Novartis, Paladin, Sunovion, and UCB. She is an investigator for AbbVie Inc., ES-therapeutics, Biohaven, and Pfizer. Maurizio F. Facheris is an employee of AbbVie Inc., and may hold AbbVie Inc. stock and/or stock options. Michael J. Soileau has received advisory/consulting fees from: AbbVie Inc., Abbott, Mertz Therapeutics, Medtronic, and Supernus. He has received research support from: AbbVie Inc., Cerevel Therapeutics, CND Lifesciences, Praxis Precision Medicine, and Teva. He has served on the speaking bureau for: AbbVie Inc., Amneal Pharmaceuticals, Kyowa Kirin, and Neurocrine Pharmaceuticals. Martha P. Arroyo is a study investigator with Leo Pharma and Allakos, and has received honoraria and consultant fees from AbbVie Inc. and BMS. She has a clinical practice through Lakeside Dermatology. Nahome Fisseha is an employee of AbbVie Inc., and may hold AbbVie Inc. stock and/or stock options. Pavnit Kukreja is an employee of AbbVie Inc., and may hold AbbVie Inc. stock and/or stock options. Robert A. Hauser serves on a scientific advisory board for Inhibikase and Stoparkinson. He has received consulting fees from AbbVie Inc., Amneal Pharmaceuticals, Avanex, Biogen, BlueRock Therapeutics, Forsee Pharmaceuticals, Global Kinetics, Inhibikase, Jazz Pharmaceuticals, Kyowa Kirin, MDCE Suzhou, MedRhythms, Merck, Merz, Neurocrine, Neuroderm, Ovid Therapeutics, PD Neurotechnology, Pharma Two B, Regenxbio, Revance, Sage Therapeutics, Scion NeuroStim, Stoparkinson, Sunovion, Supernus Pharmaceuticals, Tolmar, Tremor Research Group, Tris Pharma, UCB, and Vivifi Biotech. He has received speaking fees from Acorda, Amneal Pharmaceuticals, Cerevel, Inhibikase, Kyowa Kirin, Neurocrine Biosciences, Sunovion, and Supernus. His University has received research support from AbbVie Inc., Aeon Biopharma, Annovis Bio Inc., Artizan Biosciences, Biogen MA, Bukwang Pharmaceutical Co. Ltd., Cavion Inc., Cerevance Inc., Cerevel Therapeutics, Cynapsus Therapeutics, Enterin Inc., Genetech, Global Kinetics Corporation, Hoffman-La Roche Inc., Impax Laboratories, Inhibikase Therapeutics, Integrative Research Laboratories Sweden, Lundbeck Inc., Michael J. Fox Foundation for Parkinson’s Research, National Parkinson’s Foundation, Neuraly Inc., Neurocrine Biosciences, Neuroderm, Parkinson’s & Movement Disorder Alliance, Pharma Two B Ltd., Revance Therapeutics, Sage Therapeutics, Sanofi Pharmaceuticals, Scion NeuroStim, SunPharma, and UCB BioPharma. He holds stock options in Axial Therapeutics, Enterin, and Inhibikase as well as holds stock in Revance Therapeutics. He has received intellectual property interests from a Parkinson’s Disease Diary through his University. He acknowledges a Center of Excellence grant from the Parkinson Foundation. Rajesh Pahwa serves as a consultant for Abbott, AbbVie Inc., ACADIA, Acorda, Adamas, Amneal, CalaHealth, Global Kinetics, Impel, Neuropharma, Kyowa, Lundbeck, Mitsubishi, Neurocrine, Orbis Bioscience, PhotoPharmics, Prilenia, Sunovion, Teva Neuroscience, and US WorldMeds. He receives research support from Abbott, AbbVie Inc., Addex, Biogen, Biohaven, Boston Scientific, EIP, Global Kinetics, Impax, Intec, Lilly, Neuroderm, Neuraly, Parkinson’s Foundation, Pharma 2B, Prelinia, Roche, SIS, Sun Pharma, Sunovion, Theranexus, Theravance, US WorldMeds, and Voyager. He is also an investigator for AbbVie Inc. Sarah Bray has received advisory fees from AbbVie Inc., receives a salary from NSW Health, and is a Nurse Coordinator on studies funded by AbbVie Inc. Sara Dhanani received advisory honoraria from Amneal and AbbVie Inc., and is an investigator on studies funded by AbbVie Inc. Saritha Talapala is an employee of AbbVie Inc., and may hold AbbVie Inc. stock and/or stock options. Victor S. C. Fung receives a salary from NSW Health; has received unrestricted research grants from the Michael J. Fox Foundation, AbbVie Inc., and Merz; and receives royalties from Health Press Ltd. and Taylor and Francis Group LLC., (© 2024 AbbVie Inc.)

A 70-year-old male who has medical history of Parkinson's disease for 26 years admitted to our hospital for trial of levodopa carbidopa intestinal gel (LCIG) therapy because of severe dyskinesia and frequent wearing-off. He developed deterioration when he was treated with one of the levodopa (LD) decacrboxylase inhibitor compounds in the past. Five days after LD had changed into equivalent dose of LD/carbidopa (CD), high fever with hyperCKemia appeared. He was diagnosed as having Parkinsonism-hyperpyrexia syndrome (PHS). Exchange of LD/CD to LD drugs improved the symptoms quickly. Four days after LCIG administration, PHS reappeared. Simultaneously, the patient developed sepsis and disseminated intravascular coagulation (DIC). Thrombocytopenia did not improve after recovery from infection and DIC. Anti-PA IgG and drug-induced lymphocyte stimulation test (DLST) against LCIG showed positive. Exchange of LCIG to LD drugs and intravenous methylprednisolone administration improved the symptoms and thrombocytopenia. CD induced type II and type IV allergy were suspected. This case offers a caution that physicians should be aware of drug allergy in cases of which unexpected symptoms occurred in altering one LD compound to another.

Cannabidiol (CBD), a non-psychoactive compound derived from Cannabis Sativa, has garnered increasing attention for its diverse therapeutic potential. This comprehensive review delves into the complex pharmacokinetics of CBD, including factors such as bioavailability, distribution, safety profile, and dosage recommendations, which contribute to the compound's pharmacological profile. CBD's role as a pharmacological inhibitor is explored, encompassing interactions with the endocannabinoid system and ion channels. The compound's anti-inflammatory effects, influencing the Interferon-beta and NF-κB, position it as a versatile candidate for immune system regulation and interventions in inflammatory processes. The historical context of Cannabis Sativa's use for recreational and medicinal purposes adds depth to the discussion, emphasizing CBD's emergence as a pivotal phytocannabinoid. As research continues, CBD's integration into clinical practice holds promise for revolutionizing treatment approaches and enhancing patient outcomes. The evolution in CBD research encourages ongoing exploration, offering the prospect of unlocking new therapeutic utility.

Background: The NKX2-1-related disorders (NKX2-1-RD) is a rare disorder characterized by choreiform movements along with respiratory and endocrine abnormalities. The European Reference Network of Rare Neurological Disorders funded by the European Commission conducted a systematic review to assess drug treatment of chorea in NKX2-1-RD, aiming to provide clinical recommendations for its management., Methods: A systematic pairwise review using various databases, including MEDLINE, Embase, Cochrane, CINAHL, and PsycInfo, was conducted. The review included patients diagnosed with chorea and NKX2-1-RD genetic diagnosis, drug therapy as intervention, no comparator, and outcomes of chorea improvement and adverse events. The methodological quality of the studies was assessed, and the study protocol was registered in PROSPERO., Results: Of the 1417 studies examined, 28 studies met the selection criteria, consisting of 68 patients. The studies reported 22 different treatments for chorea, including carbidopa/levodopa, tetrabenazine, clonazepam, methylphenidate, carbamazepine, topiramate, trihexyphenidyl, haloperidol, propranolol, risperidone, and valproate. No clinical improvements were observed with carbidopa/levodopa, tetrabenazine, or clonazepam, and various adverse effects were reported. However, most patients treated with methylphenidate experienced improvements in chorea and reported only a few negative effects. The quality of evidence was determined to be low., Conclusions: The management of chorea in individuals with NKX2-1-RD presents significant heterogeneity and lack of clarity. While the available evidence suggests that methylphenidate may be effective in improving chorea symptoms, the findings should be interpreted with caution due to the limitations of the studies reviewed. Nonetheless, more rigorous and comprehensive studies are necessary to provide sufficient evidence for clinical recommendations., (© 2023 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

The quality of life of patients affected by Parkinson's disease is improved by medications containing levodopa and carbidopa, restoring the dopamine concentration in the brain. Accordingly, the affordable quality control of such pharmaceuticals is very important. Here is reported the simple and inexpensive colorimetric quantification of carbidopa in anti-Parkinson drugs by the selective condensation reaction between the hydrazine group from carbidopa and the formyl functional group of selected aldehydes in acidified hydroalcoholic solution. An optical assay was developed by using indole-3-carbaldehyde (I3A) giving a yellow aldazine in EtOH:H 2 O 1:1 (λ max ~415 nm) at 70 °C for 4 h, as confirmed by LC-MS analysis. A filter-based plate reader was used for colorimetric data acquisition, providing superior results in terms of analytical performances for I3A, with a sensitivity ~50 L g -1 and LOD ~0.1 mg L -1 in comparison to a previous study based on vanillin, giving, for the same figures of merit values, about 13 L g -1 and 0.2-0.3 mg L -1 , respectively. The calibration curves for the standard solution and drugs were almost superimposable, therefore excluding interference from the excipients and additives, with very good reproducibility ( av RSD% 2-4%) within the linear dynamic range (10 mg L -1 -50 mg L -1 ).

In the advanced Parkinson's disease, motor and non-motor symptoms become more severe and more difficult to treat. Oral therapy may become insufficient in controlling a patient´s motor complications, which results in a substantial deterioration of the patient's quality of life, ability to work and self-reliance. This is when device-aided treatments should be considered and offered, if suitable for a given patient. They include subcutaneous and intestinal infusion therapies, deep brain stimulation and, more recently, MRI-guided focussed ultrasound. Device-aided treatments should be offered in accordance with guidelines and treatment standardization. Also there is a need to ensure availability of treatment and education of patients and physicians., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

The standard of care is a term that refers to the level of care, skill, and treatment that a healthcare provider should offer to a patient based on the current scientific evidence and the level of medical knowledge available in the field. For Parkinson's disease (PD), the standard care is mostly considered to be oral treatment with dopaminergic drugs, particularly levodopa which remains the 'gold standard'. However, effective management with levodopa during the later stages of the disease becomes increasingly challenging due to the ongoing neurodegenerative process, the consequences of its pulsatile dopaminergic stimulation, and the gastrointestinal barriers to effective drug absorption. As a result, the concept of applying continuous dopaminergic stimulation has emerged with infusion therapies (continuous subcutaneous apomorphine, levodopa-carbidopa intestinal gel, and levodopa-entacapone-carbidopa intestinal gel infusion). These therapies seek to provide continuous stimulation of striatal dopamine receptors that is efficient not only in alleviating clinical symptoms, but also in delaying, reducing, and possibly preventing the onset of levodopa-related motor (fluctuations, dyskinesia) and non-motor complications; and they are also associated with clinically relevant side effects. Clinical studies and real-life experience support the notion that infusion therapies should be accepted as part of the standard of care for patients with advanced PD who have refractory, severe, and disabling motor complications that affect their quality of life. However, they should be considered based on the needs of individualized patients and the access to these advanced therapies needs to be made more accessible to the general PD population., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Pump-guided intrajejunal levodopa administration is one of the indispensable forms of therapy in advanced Parkinson's syndrome, along with deep brain stimulation and subcutaneous apomorphine injection. The standard application of levodopa gel via a JET-PEG, i.e. a percutaneous endoscopic gastrostomy (PEG) with an inserted internal catheter into the jejunum, has not been unproblematic due to the restricted absorption area of the drug in the region of the flexura duodenojejunalis and especially due to the sometimes considerable accumulated complication rates of a JET-PEG. Causes of complications are mainly a non-optimal application technique of PEG and internal catheter as well as the often missing adequate follow-up care. This article presents the details of a-compared to the conventional technique-modified and optimised application technique, which has been clinically proven successfully for years. However, many details derived from anatomical, physiological, surgical and endoscopic aspects must be strictly observed during the application to reduce or avoid minor and major complications. Local infections and buried bumper syndrome cause particular problems. The relatively frequent dislocations of the internal catheter (which can ultimately be avoided by clip-fixing the catheter tip) also prove to be particularly troublesome. Finally, using the Hybrid technique, a new combination of an endoscopically controlled gastropexy with 3 sutures and subsequent central thread pull-through (TPT) of the PEG tube, the complication rate can be dramatically reduced and thus a decisive improvement achieved for patients. The aspects discussed here are highly relevant for all those involved in the therapy of advanced Parkinson's syndrome., (© 2023. The Author(s).)

This article provides an overview of the various screening and selection tools which have been developed over the past 25 years to identify patients with Parkinson's disease (PD) possibly eligible for device-aided therapies (DATs). For the available screening tools, we describe the target therapies (subtypes of DAT), development methods, validation data, and their use in clinical practice. In addition, the historical background and potential utility of these screening tools are discussed. The challenges in developing and validating these tools are also addressed, taking into account the differences in population, the local health care organization, and resource availability., (© 2023. The Author(s).)

Advanced Parkinson's disease is characterized by periods of poor mobility, dyskinesia and progressive decline in functional independence of the affected person despite the manipulation of levodopa doses and the introduction of supplemental therapies such as catechol-O-methyl transferase inhibitors, monoamine oxidase-B inhibitors and dopamine agonists. The implementation of drug delivery systems allows to bypass problems related to irregular and often unpredictable intestinal absorption of oral levodopa, which significantly affects its bioavailability and contributes to the development and persistence of motor complications. Subcutaneous apomorphine and levodopa/carbidopa jejunal infusion systems have been available for many years and their efficacy is confirmed by randomized studies and long-term experience in many centers worldwide. Recently, a new formulation of levodopa/carbidopa infusion gel that includes the catechol-O-methyl transferase inhibitor Entacapone has been introduced to the market. The use of entacapone allows to reduce total daily dose of administered levodopa. Two different soluble formulations of levodopa/carbidopa (ND0612 and ABBV-951) have completed clinical development, and both can ensure subcutaneous delivery by a portable pump infusion system. ABBV-951 uses a foslevodopa/foscarbidopa formulation, both prodrugs to improve absorption and tolerability. Both systems provide effective improvement of motor complications and are likely to expand the therapeutic options in advanced patients. Future efforts should focus on the earlier detection of patients who are candidates for device-aided therapies, increasing appropriate referral and broadening the availability of these treatments globally., (© 2023. The Author(s).)

Introduction: Constipation is one of the most frequent non-motor symptoms of Parkinson's disease (PD), and magnesium oxide (MgO) is a frequently used laxative. This study aimed to investigate the effect of concomitant use of MgO on the pharmacokinetics of levodopa preparations in patients with PD., Methods: We prospectively enrolled 35 patients with PD and compared the pharmacokinetics of levodopa and carbidopa and motor symptoms with and without MgO. The impact of alterations in pH and the addition of MgO on the solubility of levodopa formulations were also evaluated under in vitro conditions., Results: Concomitant use of MgO significantly reduced the maximum plasma concentration of levodopa (Cmax) (from 7.66 ± 3.74 μmol/L to 5.82 ± 3.69 μmol/L; p  = 0.006) and area under the plasma concentration-time curve 3 h after drug administration (AUC 3h , from 9.64 ± 3.23 μmol·h/L to 7.39 ± 3.15 μmol·h/L; p  < 0.001), and further decreased carbidopa Cmax (from 64.02 ± 27.02 ng/mL to 38.83 ± 21.94 μmol/L; p  < 0.001) and AUC 3h (from 130.58 ± 65.64 ng/mL to 76.48 ± 52.24 ng·h/mL; p  < 0.001). The Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale part III score also deteriorated significantly (from 30.71 ± 11.34 to 32.06 ± 11.22; p  = 0.007). MgO significantly affected the pharmacokinetics of levodopa and carbidopa. This also applied when the findings were analyzed by sex and age. In vitro dissolution experiments revealed a decrease in the relative concentrations of levodopa, carbidopa, and benserazide as the pH increased and in the presence of MgO suspension, with the most prominent impact on benserazide., Conclusions: Concomitant use of MgO and levodopa should be discouraged to improve levodopa absorption., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Author(s).)

Background: It is known that the pharmacokinetics (PK) of levodopa (LD) varies considerably. Difference in PK shapes is expected to affect drug efficacy and development of dyskinesia. In this study, the authors aimed to explore correlations between PK series data of LD and clinical characteristics and dyskinesia in patients with Parkinson's disease (PD)., Methods: We studied 270 PD patients who underwent PK assessment after administration of LD/carbidopa (100/10 mg) in non-compartmental analysis. The patients were grouped according to similarities in time series data of blood LD concentration. Each group was analyzed with respect to clinical characteristics and PK parameters. We created a model to predict PK patterns based on these findings., Results: PD patients were divided into three groups by clustering analysis: blood LD concentration of the patients in Groups 1 (n = 129), 3 (n = 44) and 2 (n = 97) rose rapidly, relatively slowly and at an intermediate rate, respectively. There were no statistically significant differences in patient characteristics except age among the three groups (one-way ANOVA). Multivariate analysis showed that frequency of dyskinesias in Group 1 was significantly higher than that in Group 2. We successfully created a PK pattern prediction model based on body weight and blood LD concentration at 15 and 30 min after administration., Conclusions: The PK series data of LD was classified into three patterns. The rapid absorption was associated with dyskinesias. Patients' PK patterns were successfully predicted based on their body weight and two-point LD concentration., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

3D printing offers the possibility to prepare personalized tablets on demand, making it an intriguing technology for hospital pharmacies. For the implementation of 3D-printed tablets into the digital Closed Loop Medication Management system, the required tablet formulation and development of the manufacturing process as well as the pharmaceutical validation were conducted. The goal of the formulation development was to enable an optimal printing process and rapid dissolution of the printed tablets for the selected model drugs Levodopa/Carbidopa. The 3D printed tablets were prepared by direct powder extrusion. Printability, thermal properties, disintegration, dissolution, physical properties and storage stability were investigated by employing analytical methods such as HPLC-UV, DSC and TGA. The developed formulation shows a high dose accuracy and an immediate drug release for Levodopa. In addition, the tablets exhibit high crushing strength and very low friability. Unfortunately, Carbidopa did not tolerate the printing process. This is the first study to develop an immediate release excipient composition via direct powder extrusion in a hospital pharmacy setting. The developed process is suitable for the implementation in Closed-Loop Medication Management systems in hospital pharmacies and could therefore contribute to medication safety., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Here we focus on people with advanced PD undergoing percutaneous endoscopic transgastric jejunostomy (PEG-J) ("one stone") for LCIG infusion therapy for managing severe motor fluctuations ("first bird") and discuss its implications for improving accompanying symptoms of cardiovascular, urinary, and gastrointestinal autonomic failure ("second bird")., Competing Interests: Declaration of competing interest The authors declare no conflicts of interests related to the present manuscript., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The spatial extent of marine and terrestrial protected areas (PAs) was among the most intensely debated issues prior to the decision about the post-2020 Global Biodiversity Framework (GBF) of the Convention on Biological Diversity. Positive impacts of PAs on habitats, species diversity and abundance are well documented. Yet, biodiversity loss continues unabated despite efforts to protect 17% of land and 10% of the oceans by 2020. This casts doubt on whether extending PAs to 30%, the agreed target in the Kunming-Montreal GBF, will indeed achieve meaningful biodiversity benefits. Critically, the focus on area coverage obscures the importance of PA effectiveness and overlooks concerns about the impact of PAs on other sustainability objectives. We propose a simple means of assessing and visualising the complex relationships between PA area coverage and effectiveness and their effects on biodiversity conservation, nature-based climate mitigation and food production. Our analysis illustrates how achieving a 30% PA global target could be beneficial for biodiversity and climate. It also highlights important caveats: (i) achieving lofty area coverage objectives alone will be of little benefit without concomitant improvements in effectiveness, (ii) trade-offs with food production particularly for high levels of coverage and effectiveness are likely and (iii) important differences in terrestrial and marine systems need to be recognized when setting and implementing PA targets. The CBD's call for a significant increase in PA will need to be accompanied by clear PA effectiveness goals to reduce and revert dangerous anthropogenic impacts on socio-ecological systems and biodiversity., (© 2023 The Authors. Global Change Biology published by John Wiley & Sons Ltd.)

Levodopa (L-DOPA) treatment, combined with the administration of dopa-decarboxylase inhibitors (DDCIs), is still the most effective symptomatic treatment of Parkinson's disease (PD). Although its efficacy in the early stage of the disease has been confirmed, its complex pharmacokinetics (PK) increases the variability of the intra-individual motor response, thus amplifying the risk of motor/non-motor fluctuations and dyskinesia. Moreover, it has been demonstrated that L-DOPA PK is strongly influenced by several clinical, therapeutic, and lifestyle variables (e.g., dietary proteins). L-DOPA therapeutic monitoring is therefore crucial to provide personalized therapy, hence improving drug efficacy and safety. To this aim, we have developed and validated an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to quantify L-DOPA, levodopa methyl ester (LDME), and the DDCI carbidopa in human plasma. The compounds were extracted by protein precipitation and samples were analyzed with a triple quadrupole mass spectrometer. The method showed good selectivity and specificity for all compounds. No carryover was observed, and dilution integrity was demonstrated. No matrix effect could be retrieved; intra-day and inter-day precision and accuracy values met the acceptance criteria. Reinjection reproducibility was assessed. The described method was successfully applied to a 45-year-old male patient to compare the pharmacokinetic behavior of an L-DOPA-based medical treatment involving commercially available Mucuna pruriens extracts and an LDME/carbidopa (100/25 mg) formulation.

Background: While immediate benefits of levodopa-carbidopa intestinal gel (LCIG) are evident in patients with Parkinson's disease (PD), long-term LCIG effects require further study., Objectives: We explored long-term LCIG on motor symptoms, nonmotor symptoms (NMS), and LCIG treatment settings in patients with advanced PD (APD)., Methods: Data were obtained (medical records and patient visit) from COSMOS, a multinational, retrospective, cross-sectional post-marketing observational study in patients with APD. Patients were stratified into 5 groups based on LCIG treatment duration at the patient visit, from 1-2 to > 5 years LCIG. Between-group differences were assessed for changes from baseline in LCIG settings, motor symptoms, NMS, add-on medications, and safety., Results: Out of 387 patients, the number of patients per LCIG group was: > 1- ≤ 2 years LCIG (n = 156); > 2- ≤ 3 years LCIG (n = 80); > 3- ≤ 4 years LCIG (n = 61); > 4- ≤ 5 years LCIG (n = 30); > 5 years LCIG (n = 60). Baseline values were similar; data reported are changes from the baseline. There were reductions in "off" time, dyskinesia duration, and severity across LCIG groups. Prevalence, severity, and frequency of many individual motor symptoms and some NMS were reduced amongst all LCIG groups, with few differences between groups. Doses for LCIG, LEDD and LEDD for add-on medications were similar across groups both at LCIG initiation and patient visit. Adverse events were similar across all LCIG groups and consistent with the established safety profile of LCIG., Conclusions: LCIG may provide sustained, long-term symptom control, while potentially avoiding increases in add-on medication dosages., Trial Registration: ClinicalTrials.gov Identifier: NCT03362879. Number and date: P16-831, November 30, 2017., (© 2023. The Author(s).)

Severe fever with thrombocytopenia syndrome is a hemorrhagic fever caused by a tick-borne infection. The causative agent, Dabie bandavirus, is also called the severe fever with thrombocytopenia syndrome virus (SFTSV). Ogawa et al. (2022) reported that levodopa, an antiparkinsonian drug with an o-dihydroxybenzene backbone, which is important for anti-SFTSV activity, inhibited SFTSV infection. Levodopa is metabolized by dopa decarboxylase (DDC) and catechol-O-methyltransferase (COMT) in vivo. We evaluated the anti-SFTSV efficacy of two DDC inhibitors, benserazide hydrochloride and carbidopa, and two COMT inhibitors, entacapone and nitecapone, which also have an o-dihydroxybenzene backbone. Only DDC inhibitors inhibited SFTSV infection with pretreatment of the virus (half-maximal inhibitory concentration [IC 50 ]: 9.0-23.6 μM), whereas all the drugs inhibited SFTSV infection when infected cells were treated (IC 50 : 21.3-94.2 μM). Levodopa combined with carbidopa and/or entacapone inhibited SFTSV infection in both conditions: pretreatment of the virus (IC 50 : 2.9-5.8 μM) and treatment of infected cells (IC 50 : 10.7-15.4 μM). The IC 50 of levodopa in the above-mentioned study for pretreatment of the virus and treatment of infected cells were 4.5 and 21.4 μM, respectively. This suggests that a synergistic effect was observed, especially for treatment of infected cells, although the effect is unclear for pretreatment of the virus. This study demonstrates the anti-SFTSV efficacy of levodopa-metabolizing enzyme inhibitors in vitro. These drugs may increase the time for which the levodopa concentration is maintained in vivo. The combination of levodopa and levodopa-metabolizing enzyme inhibitors might be a candidate for drug repurposing., Competing Interests: Declaration of competing interest None., (Copyright © 2023 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.)

Introduction: IPX203 is a novel oral extended-release (ER) formulation of carbidopa (CD) and levodopa (LD) developed to address the short half-life and limited area for absorption of LD in the gastrointestinal tract. This paper presents the formulation strategy of IPX203 and its relationship to the pharmacokinetics (PK) and pharmacodynamic profile of IPX203 in Parkinson's disease (PD) patients., Methods: IPX203 was developed with an innovative technology containing immediate-release (IR) granules and ER beads that provides rapid LD absorption to achieve desired plasma concentration and maintaining it within the therapeutic range for longer than can be achieved with current oral LD formulations. The PK and pharmacodynamics of IPX203 were compared with IR CD-LD in a Phase 2, open-label, rater-blinded, multicenter, crossover study in patients with advanced PD., Results: Pharmacokinetic data showed that on Day 15, LD concentrations were sustained above 50% of peak for 6.2 h with IPX203 vs. 3.9 h with IR CD-LD ( P  = 0.0002). Pharmacodynamic analysis demonstrated that mean MDS-UPDRS Part III scores prior to administration of the first daily dose were significantly lower among patients receiving IPX203 than IR CD-LD (LS mean difference -8.1 [25.0], P  = 0.0255). In a study conducted in healthy volunteers, a high-fat, high-calorie meal delayed plasma LD T max by 2 h, and increased C max and AUC tau by approximately 20% compared with a fasted state. Sprinkling capsule contents on applesauce did not affect PK parameters., Conclusion: These data confirm that the unique design of IPX203 addresses some of the limitations of oral LD delivery., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: P.L. has served as a consultant or investigator in clinical trials sponsored by Acorda Therapeutics, Amneal, Appello, Axovant, Aptinyx, Biogen, Biotie, Bukwang Pharmaceutical, Cavion, Cerevel, Denali Therapeutics, F. Hoffmann-LaRoche, Impax Laboratories Inc., Impel Neuropharma, Ipsen, Kyowa Hakko Kirin, Lundbeck A/S, the Michael J. Fox Foundation for Parkinson’s Research, Mitsubishi Tanabe Pharma, Neurocrine Biosciences, NeuroDerm Ltd, Noven, Parkinson Study Group, Pharma Two B, Prexton Therapeutics, Revance Therapeutics, Saccadous, Sun Pharma, and US WorldMeds. He has received speaking fees from Acorda Therapeutics, Britannia, the American Academy of Neurology, the International Parkinson and Movement Disorder Society, Kyowa Hakko Kirin, Neurocrine Biosciences, Paladin Labs, US WorldMeds, and the World Parkinson Congress. He is compensated for services as editor-in-chief of Clinical Neuropharmacology and serves without compensation on the editorial boards of Journal of Neural Transmission, Translational Neurodegeneration, and Journal of Parkinson’s Disease. A.E. has received speaking and consulting fees from AbbVie/Allergan, Acadia, Acorda Therapeutics, Adamas, Affiris, Amneal, Biohaven, Cerevel, Ipsen, NeuroDerm, Teva, US WorldMeds, and XW Labs. D.B. has received research support for clinical trials from AbbVie, Amneal, Athira Pharma, Axial Biotherapeutics, Cerevel, Enterin, Jazz Pharmaceuticals, Merck, Neuraly, Pharma Two B, and Praxis. S.G. has received research funding from the NIH and has participated in clinical studies funded by Biogen, Amneal, Parkinson Foundation, and the Michael J. Fox Foundation. R.G. has received speaking and consulting fees, as well as payment for his participation in clinical research trials as principal investigator, from companies including, but not limited to: Allergan, Adamas, Teva, Ipsen, US WorldMeds, Impax, Sunovion, AbbVie, Kyowa, Cynapsus, Neurocrine, Pharma Two B, Lundbeck, Novartis, Boehringer Ingelheim, GlaxoSmithKline, Amneal, Merz, Acadia, Medtronic, Merz, Abbott, and NeuroDerm. R.D. has participated as a clinical trial investigator in clinical studies funded by Amneal, Pharma Two B, AbbVie, NeuroDerm, Cerevel, Neurocrine/HSG, Neuraly, Alexion, Global Kinetics, AEON Biopharma, Praxis, and Sage Therapeutics. He has received grants from UAMS Translational Research Institute. He has served as a consultant for Best Doctors Inc. and Synergic Medical Technologies. He owns stock in Biogen, Gilead Sciences, Imara, Atea Pharmaceuticals, and Compass Pathways. G.B. and R.D. are employees of Amneal Pharmaceuticals, LLC., (© 2023 The Author(s).)

Background: Tyrosine hydroxylase deficiency (THD) is a rare movement disorder with broad phenotypic expression caused by bi-allelic mutations in the TH gene, which encode for tyrosine hydroxylase (TH) protein. Some patients with THD have improvement in dystonia with carbidopa-levodopa, a synthetic form of dopamine typically used in Parkinson's disease, and are considered to have dopa-responsive THD. THD has been found in 0.5-1 per million persons, although due to overlapping symptoms with other disorders and the need for genetic testing, prevalence is likely underestimated. Existing literature describes some patients with THD having intellectual disability, but comorbid autism spectrum disorder (ASD) has not been reported., Case Presentation: A nearly 3-year-old boy was referred to pediatric neurology due to hypotonia, delayed motor milestones, and expressive speech delay. Whole exome sequencing confirmed tyrosine hydroxylase deficiency, detecting a novel variant p.S307C first reported here. The child was treated with carbidopa-levodopa with an excellent response, resulting in improved balance, fewer falls, and improved ability to jump, run and climb stairs. He was determined to have dopa-responsive THD. Due to his delays in expressive speech, the boy also had an assessment with a developmental and behavioral pediatrician, who identified a pattern of social pragmatic speech delay, sensory sensitivities, and restricted interests, and determined that he met criteria for a diagnosis of ASD., Conclusions: While ASD can stand alone as a clinical diagnosis, it is also a cardinal feature of other genetically-based neurological disorders. To our knowledge, this is the first case that describes a patient with both disorders. Perhaps THD may be among the genetic disorders linked with ASD., (© 2023. The Author(s).)

The use of catechol-O-methyltransferase inhibitors may mask doping agents, primarily levodopa, administered to racehorses and prolong the stimulating effects of dopaminergic compounds such as dopamine. It is known that 3-methoxytyramine is a metabolite of dopamine and 3-methoxytyrosine is a metabolite of levodopa thus these compounds are proposed to be potential biomarkers of interest. Previous research established a urinary threshold of 4,000 ng/mL for 3-methoxytyramine to monitor misuse of dopaminergic agents. However, there is no equivalent biomarker in plasma. To address this deficiency a rapid protein precipitation method was developed and validated to isolate target compounds from 100 µL equine plasma. A liquid chromatography-high resolution accurate mass (LC-HRAM) method using an IMTAKT Intrada amino acid column provided quantitative analysis of 3-methoxytyrosine (3-MTyr) with lower limit of quantification of 5 ng/mL. Reference population profiling (n = 1129) investigated the expected basal concentrations for raceday samples from equine athletes and showed a right-skewed distribution (skewness = 2.39, kurtosis = 10.65) which resulted from large variation (RSD = 71%) within the data. Logarithmic transformation of the data provided a normal distribution (skewness = 0.26, kurtosis = 3.23) resulting in the proposal of a conservative threshold for plasma 3-MTyr of 1,000 ng/mL at a 99.995% confidence level. A 12-horse administration study of Stalevo® (800 mg L-DOPA, 200 mg carbidopa, 1600 mg entacapone) revealed elevated 3-MTyr concentrations for 24-hours post-administration., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Introduction: Complex polypharmacy regimens to manage persistent motor fluctuations result in significant pill burden for patients with advanced Parkinson's disease (APD). This study evaluated the effectiveness of carbidopa/levodopa enteral suspension (CLES) and deep brain stimulation (DBS) on reducing pill burden in APD patients., Methods: We utilized 100% Medicare fee-for-service claims from 2014 to 2018 linked to CLES Patient Support Program (PSP) data. CLES initiators (CLES-I) were propensity matched 1:1 with patients enrolled in PSP who did not initiate treatment (CLES-NI) (N = 188) or undergo DBS, and 1:3 with patients who received DBS (N = 204, N = 612). Average daily pill burden and levodopa equivalent daily dosage (LEDD) were measured at baseline, 0-6 months and 7-12 months follow-up., Results: CLES-I and CLES-NI had higher pill burden than DBS patients at baseline. However, at 6 months post-treatment, CLES-I had significantly fewer pills/day than CLES-NI (4.7 versus 11.4, p < 0.05) and DBS (4.8 versus 7.4, p < 0.05). A significant reduction in pill burden was observed at 0-6 months (46.3%) and 7-12 months (68.3%) follow-up for CLES-I (p < 0.001) versus increased burden for CLES-NI (+10.5%, p < 0.05 and +8.2%, p > 0.05) and insignificant reductions for DBS (-3.9% and -6.1%, p > 0.05). Mean adjusted pill burden showed 57.3% fewer pills at 0-6 months and 74.1% at 7-12 months among CLES-I compared with CLES-NI, and 49.6% and 70.1% reduction compared with DBS. CLES-I showed a decrease in LEDD at 7-12 months compared with baseline (935 to 237 mg) and to CLES-NI (237 mg versus 1112 mg) and DBS patients (236 mg versus 594 mg)., Conclusion: CLES led to a significant reduction in pill burden and oral LEDD compared with CLES-NI and DBS patients. Pill burden reduction could be considered a treatment goal for patients with APD challenged by complex polypharmacy regimens that interfere with activities of daily living and quality of life., (© 2023. The Author(s).)

Objectives: Levodopa (LD) administered with dopa decarboxylase inhibitor is predominantly metabolized in the periphery by catechol- O -methyltransferase (COMT) to 3- O -methyldopa (3-OMD). Catechol- O -methyltransferase inhibition can improve treatment outcomes by decreasing variability in circulating LD concentrations. Opicapone is a once-daily COMT inhibitor approved in the US adjunctive to carbidopa (CD)/LD in patients with Parkinson disease experiencing "OFF" episodes. This study aimed to evaluate the pharmacokinetics and pharmacodynamics of once-daily opicapone 50 mg adjunctive to CD/LD in patients with stable Parkinson disease., Methods: Once-daily opicapone 50 mg was administered the evenings of days 1 to 14. Participants were randomized to receive CD/LD (25/100 mg) every 3 or 4 hours (Q3H or Q4H). Participants received Q3H or Q4H CD/LD on days 1, 2, and 15 and their usual CD/LD regimen on other days. Serial blood samples were collected to determine plasma opicapone, LD, and 3-OMD concentrations and erythrocyte soluble COMT (S-COMT) activity. The effects of opicapone on S-COMT, LD, and 3-OMD were assessed. Mean (SD) values are presented., Results: Sixteen participants were enrolled. At steady-state (day 14), opicapone Cmax (peak plasma concentration) and AUC 0-last (area under the curve-time curve) were 459 ± 252 ng/mL and 2022 ± 783 ng/mL·h, respectively. Maximum COMT inhibition was 83.4 ± 4.9% of baseline on day 14. After opicapone administration, LD total AUC, peak concentration, and trough concentration increased; peak-to-trough fluctuation index decreased. Correspondingly, 3-OMD total AUC, peak concentration, and trough concentration decreased., Conclusions: Adding once-daily opicapone 50 mg to LD resulted in marked and extended COMT inhibition, which increased systemic exposure to LD. These changes translated into higher trough concentrations and decreased peak-to-trough fluctuations for LD., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Ethnopharmacological Relevance: Parkinson's disease (PD) is a prominent health challenge characterized by complex aetiology and limited therapeutic breakthroughs. Datura metel (DM) is a medicinal plant containing active phytoconstituents with neuropharmacological potentials. In traditional medicine, it exerts anticholinergic, anti-inflammatory and antioxidant effects, and protection from organophosphate poisoning inclusively involved in the pharmacotherapy of PD. Its other PD-related medicinal potency includes treatment of motor sickness and bradycardia. However, the exact mechanisms of anti-PD effects of its phytoconstituents remain underexplored., Materials and Methods: In this study, methanolic extract of DM was evaluated for anti-PD behavioural effects in vivo haloperidol-induced cataleptic mice. The GC-MS-identified phytochemicals were studied for one-drug-multi-target inhibitory mechanisms against some key targets for PD treatment, alpha-synuclein (ASN) and dopa decarboxylase (DDC) using molecular docking., Results: and discussion: Chronic administration of 50, 100 and 200 mg/kg of DM extract improved the 14-s latency time induced by haloperidol to 54, 54 and 57 s respectively, whereas levodopa (30 mg/kg) produced 47 s in rotarod tests. Similarly, the descending times for haloperidol-induced cataleptic mice were significantly reduced from 110 s to 17.7, 17.7 and 12.5 s by the respective chronic doses of DM extract, whereas levodopa-administered mice spent 17.5 s descending the same 30 cm pole. The interesting motor coordination enhancements are suggestively due to synergistic inhibition of ASN and DCC by the phytoconstituents of DM, especially, atropine and scopolamine. From the docking analysis, the two phytochemicals interacted more potently with the active therapeutic sites of the dual targets than levodopa and carbidopa., Conclusion: Methanolic extract of DM contains active phytochemicals for multi-target-directed antiparkinsonian mechanisms amenable for further studies., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Herein, to monitor the concentration of carbidopa in an aqueous solution, an analytical approach based on electrode surface modification by Pt/SWCNTs as a sensor has been proposed. Pt/SWCNTs was synthesized by polyol strategy and characterized by the TEM method. Results confirmed spherical Pt nanoparticles with a diameter of about 10 nm decorated at the surface of SWCNTs with good distribution. The carbon paste electrode modified (CPEM) with Pt/SWCNTs was fabricated by mixing 12% of nanocomposite as an optimum condition with graphite powder in the presence of paraffin oil as a binder. Carbidopa's oxidation signal was enhanced by about 2.73 times when using the CPEM/Pt/SWCNTs, and its oxidation potential was decreased by about 110 mV. Additionally, the sensor demonstrated a linear dynamic range of 1.0 nM-120 M with a detection limit of 0.5 nM at pH = 7.0 as the ideal condition for monitoring carbidopa. Therefore, carbidopa in water and dextrose saline can be detected using CPEM/Pt/SWCNTs with an acceptable recovery range., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objective: This study measures the relative preference for attributes of device-aided therapies (DATs) for advanced Parkinson's Disease (PD) from the perspective of Japanese neurologists., Methods: Attributes and levels were elicited based on literature and interviews with certified neurologists experienced with DATs. An online survey including a discrete choice experiment (DCE) was developed, pilot tested, and distributed through an online panel to neurologists treating advanced PD patients. Participants were asked to choose treatments among several choice sets of two hypothetical DATs described only by the attributes, or no DAT (continuing oral treatment). A conditional logit model using the Bayesian framework was developed to estimate the marginal utilities of attributes' levels, and the relative utility of treatments available to Japanese advanced PD patients or being developed in Japan was assessed., Results: The DCE survey completed by 308 neurologists showed that the attributes with the greatest influence on DAT selection were surgery requirement (relative importance of 28%), average increase in the duration of daily "on" time without dyskinesia which affects daily activities (15%), average change in cognitive function related to treatment introduction (15%), device management frequency (14%), average number of pills of oral PD medication after treatment introduction (13%), average influence of treatment on symptoms of depression (12%), and type of device (large/small) (3%). All attributes significantly influenced respondents' choices, except for external device type. Experience with DATs did not influence the directions of preferences. Out of treatment profiles representing DATs, continuous subcutaneous infusion of levodopa-carbidopa had a higher preference score than levodopa-carbidopa intestinal gel infusion and deep brain stimulation., Conclusions: Our findings suggest that Japanese neurologists would prefer a DAT without surgery requirement. Other factors related to efficacy, safety, and administration mode have a significant, but a smaller influence on prescription choices.

Oral levodopa is the gold-standard therapy for treating Parkinson's disease (PD) but after a few years of treatment the therapeutic window narrows, and patients often experience various treatment-related complications. Patients in this advanced PD stage may benefit from alternative therapy, such as continuous intrajejunal delivery of levodopa-carbidopa intestinal gel (LCIG; or carbidopa-levodopa enteral suspension), continuous intrajejunal delivery of levodopa-carbidopa-entacapone intestinal gel, or continuous subcutaneous apomorphine infusion. Consideration and initiation of infusion therapies in advanced PD are suggested before the onset of major disability. The present review summarizes clinical evidence for infusion therapy in advanced PD management, discusses available screening tools for advanced PD, and provides considerations around optimal use of infusion therapy.

Background: Tablet formulations of Parkinson's disease (PD) medications may become ineffective at managing motor fluctuations in advanced PD. The liquid formulation, levodopa carbidopa ascorbic acid solution, or LCAS, is an effective and inexpensive treatment for motor fluctuations however it remains underutilized., Objective: We compared the efficacy of LCAS with tablet formulations and Duodopa jejunal infusion through routine inpatient management using hourly functional status measures, the Timed Up and Go Test (TUG). The TUG differentiates between 'off' and 'on' states and quantifies motor fluctuations., Methods: Experienced nurses used the TUG times and functional observations recorded hourly throughout the waking day to optimize the LCAS hourly dose and the Duodopa flow rate over several days. When patients were stabilized on each of the interventions, the TUG measures were then recorded to compare the outcomes of the interventions., Results: Twenty-six participants had TUG times recorded while on one or more of the formulations: 19 had TUG times recorded on tablets, 23 on LCAS and 10 on Duodopa. TUG times on LCAS and Duodopa were significantly faster compared to tablets (p < 0.0001, p = 0.001 respectively). Severity of dyskinesia was not significantly different between formulations (p = 0.35). Daily dose for the three formulations and the hourly doses for LCAS and Duodopa did not differ significantly (p = 0.37, p = 0.19 respectively)., Conclusion: This report demonstrated the efficacy of LCAS for improving motor complications and its equivalency with Duodopa jejunal infusion.

Background and Purpose: Treatment of freezing of gait (FoG) and other Parkinson disease (PD) axial symptoms is challenging. Systematic assessments of axial symptoms at progressively increasing levodopa doses are lacking. We sought to analyze the resistance to high levodopa doses of FoG, posture, speech, and altered gait features presenting in daily-ON therapeutic condition., Methods: We performed a pre-/postinterventional study including patients treated with levodopa/carbidopa intestinal gel infusion (LCIG) with disabling FoG in daily-ON condition. Patients were evaluated at their usual LCIG infusion rate (T1), and 1 h after 1.5× (T2) and 2× (T3) increase of the LCIG infusion rate by quantitative outcome measures. The number of FoG episodes (primary outcome), posture, speech, and gait features were objectively quantified during a standardized test by a blinded rater. Changes in motor symptoms, dyskinesia, and plasma levodopa concentrations were also analyzed., Results: We evaluated 16 patients with a mean age of 69 ± 9.4 years and treated with LCIG for a mean of 2.2 ± 2.1 years. FoG improved in 83.3% of patients by increasing the levodopa doses. The number of FoG episodes significantly decreased (mean = 2.3 at T1, 1.7 at T2, 1.2 at T3; p = 0.013). Posture and speech features did not show significant changes, whereas stride length (p = 0.049), turn duration (p = 0.001), and turn velocity (p = 0.024) significantly improved on doubling the levodopa infusion rate., Conclusions: In a short-term evaluation, the increase of LCIG dose can improve "dopa-resistant" FoG and gait issues in most advanced PD patients with overall good control of motor symptoms in the absence of clinically significant dyskinesia., (© 2022 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Parkinson's disease is the second most common neurodegenerative pathology. Due to the limitations of existing therapeutic approaches, novel anti-parkinsonian medicines with non-dopamine mechanisms of action are clearly needed. One of the promising pharmacological targets for anti-Parkinson drug development is phosphodiesterase (PDE) 10A. The stimulating motor effects of PDE10A inhibition were detected only under the conditions of partial dopamine depletion. The results raise the question of whether PDE10A inhibitors are able to restore locomotor activity when dopamine levels are very low. To address this issue, we (1) developed and validated the rat model of acute severe dopamine deficiency and (2) tested the action of PDE10A inhibitor MP-10 in this model. All experiments were performed in dopamine transporter knockout (DAT-KO) rats. A tyrosine hydroxylase inhibitor, α-Methyl-DL-tyrosine (αMPT), was used as an agent to cause extreme dopamine deficiency. In vivo tests included estimation of locomotor activity and catalepsy levels in the bar test. Additionally, we evaluated the tissue content of dopamine in brain samples by HPLC analysis. The acute administration of αMPT to DAT-KO rats caused severe depletion of dopamine, immobility, and catalepsy (Dopamine-Deficient DAT-KO (DDD) rats). As expected, treatment with the L-DOPA and carbidopa combination restored the motor functions of DDD rats. Strikingly, administration of MP-10 also fully reversed immobility and catalepsy in DDD rats. According to neurochemical studies, the action of MP-10, in contrast to L-DOPA + carbidopa, seems to be dopamine-independent. These observations indicate that targeting PDE10A may represent a new promising approach in the development of non-dopamine therapies for Parkinson's disease.

In this study, a UV-vis spectrophotometric method coupled with net analyte signal (NAS) and principal component regression (PCR) as multivariate calibration methods were used for the simultaneous determination of levodopa (LEV) and carbidopa (CBD) in prepared mixtures, pharmaceutical formulation, and breast milk sample. The mean recovery of the NAS model was 98.10% and 99.60% for LEV and CBD, respectively. Also, the relative standard deviation (RSD%) values were found to be lower than 5.5% and 4% for LEV and CBD, respectively. On the other hand, the mean recovery of LEV and CBD related to the PCR method was obtained at 96.86% and 92.43%, respectively. K-Fold cross-validation was used to estimate the number of components, which was 7 and 3 with a mean square error prediction (MSEP) of 1.50 and 7.14 for LEV and CBD, respectively. The results revealed that the NAS model was better than the PCR model. Additionally, the proposed NAS-based calibration method was successfully developed for the simultaneous analyses of LEV and CBD in a commercial tablet and breast milk., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Parkinson's disease is frequently treated with combinations of levodopa/carbidopa and, at the occurrence of motor fluctuations, levodopa/carbidopa/entacapone. For these (and other) medications, using generic versions can reduce costs. To show that generic drugs are equivalent to the originator drug, regulations usually refer to the bioavailability of active ingredients, which is influenced by the selected dosage form and the chosen excipients. However, while registration trials administer drugs under standardized conditions, these conditions often do not reflect the conditions of patients' daily intake. Thus, this study aimed to characterize levodopa combinations from different manufacturers in biorelevant media. Dissolution profiles of bioequivalent levodopa/carbidopa combinations and levodopa/carbidopa/entacapone combinations were tested in different media, such as tap water, gastric fluid without pepsin and whole milk. Results showed distinct discrepancies in the drugs' dissolution profiles between manufactures. Using whole milk as a dissolution medium led to the most differing dissolution profiles. Furthermore, carbidopa was unstable in tap water and milk, and it rapidly degraded. This effect was less pronounced if entacapone was present. In contrast to reports in the literature, stability testing did not show that vitamin C helps to protect against carbidopa degradation. Entacapone hardly dissolved in an acidic environment. This study found that dissolution of bioequivalent levodopa formulations varied with changing media. Further, the stability of carbidopa was found to be critical. As an implication, an acidic environment must be ensured when these drugs are applied, and generic exchange of levodopa combinations should be considered only with great caution., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Estrogen receptor-α (ERα) promotes breast cancer, and ER-positive cancer accounts for ~ 80% of breast cancers. This subtype responds positively to hormone/endocrine therapies involving either inhibition of estrogen synthesis or blockade of estrogen action. Carbidopa, a drug used to potentiate the therapeutic efficacy of L-DOPA in Parkinson's disease, is an agonist for aryl hydrocarbon receptor (AhR). Pharmacotherapy in Parkinson's disease decreases the risk for cancers, including breast cancer. The effects of carbidopa on ER-positive breast cancer were evaluated in cell culture and in mouse xenografts. The assays included cell proliferation, apoptosis, cell migration/invasion, subcellular localization of AhR, proteasomal degradation, and tumor growth in xenografts. Carbidopa decreased proliferation and migration of ER-positive human breast cancer cells in vitro with no significant effect on ER-negative breast cancer cells. Treatment of ER-positive cells with carbidopa promoted nuclear localization of AhR and expression of AhR target genes; it also decreased cellular levels of ERα via proteasomal degradation in an AhR-dependent manner. In vivo, carbidopa suppressed the growth of ER-positive breast cancer cells in mouse xenografts; this was associated with increased apoptosis and decreased cell proliferation. Carbidopa has therapeutic potential for ER-positive breast cancer either as a single agent or in combination with other standard chemotherapies., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Patients with advanced Parkinson's disease (APD) commonly experience motor and nonmotor symptoms (NMS) associated with functional limitations and decreased quality of life. We compared motor and nonmotor outcomes in patients with APD receiving 24- versus 16-h levodopa-carbidopa intestinal gel (LCIG)., Methods: Data from COSMOS, a large, real-world, retrospective and cross-sectional, observational study on LCIG and comedication in APD were obtained from medical records and a single patient visit for patients receiving 24- and 16-h LCIG infusion. Changes from baseline were evaluated for motor symptoms, NMS, and clinical characteristics. Safety was also assessed., Results: Data for 401 patients were included in this subanalysis. At the patient visit there were 35 patients on 24-h LCIG and 366 on 16-h LCIG. "Off" time and dyskinesia (duration and severity) were reduced in both groups. In both LCIG treatment groups, prevalence of most symptoms was reduced. There were significant differences in the change from baseline in severity and frequency of freezing of gait with 24-h LCIG versus 16-h LCIG (p = 0.011 and p = 0.038), severity of urinary symptoms (p = 0.006), and frequency of cognitive impairment (p = 0.014) with 24-h LCIG versus 16-h LCIG. Adverse events were similar for both treatment groups and considered tolerable., Conclusions: LCIG 24-h infusion may be a useful treatment option, when clinically justified, for select patients with APD., Clinical Trial Number: NCT03362879., Competing Interests: Declaration of competing interest NK is a study investigator and has received honoraria from Sandoz, UCB, AbbVie, Abbott, Boston Scientific, Medtronic, KRKA, Teva, Boehringer Ingelheim, and GSK Pharmaceuticals for lecturing at symposia. He has been a consultant for AbbVie, Teva, and KRKA. He has received research funding from the Hungarian National Research Development and Innovation Office, University of Pécs, Abbott, and Medtronic. JS is a study investigator and received compensation from AbbVie, Novartis, UCB, Boehringer Ingelheim, GSK, Ever Pharma, Lundbeck, Teva, and Pfizer for speaker activities. LVD has received honoraria for educational presentations and consulting from AbbVie, Zambon, and Bial. PS is a study investigator and received compensation from AbbVie, Shire, Sanofi Genzyme, and DSMB for speaker activities. SF, JCP, OSS, and LB are employees of AbbVie Inc. and may hold AbbVie stock and/or stock options. TG is a study investigator; advisor for AbbVie, Teva, Allergan, Neuroderm, Cytora, Medison, Synnerva; and received research support from the Parkinson's Foundation and Israel innovation authorities, and travel support for her team and herself from AbbVie, Medison, Medtronic, and Allergan. AF is an external study consultant and study investigator and has served as an advisor for AbbVie, and a consultant for Abbott, Sunovion, Medtronic, Boston Scientific, Ceregate, Inbrain, Ipsen, and AbbVie. He has received research support from Medtronic, Boston Scientific, University of Toronto, Michael J Fox Foundation for Parkinson's Research, and honoraria for serving as a speaker from UCB, Abbott, Ipsen, Sunovion, Medtronic, Novartis, Chiesi, Boston Scientific, AbbVie, and Teva., (Copyright © 2022. Published by Elsevier Ltd.)