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Background: The capsule formulation of CDK4/6 inhibitor palbociclib has reduced solubility at gastric pH > 4.5 and may have decreased activity when used with proton-pump inhibitors (PPI). Herein, we report the effect of PPI on palbociclib capsule activity and safety in the PARSIFAL study. Methods: First-line endocrine-sensitive, hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) patients received palbociclib capsules plus fulvestrant or letrozole. The primary endpoint was progression-free survival (PFS). This post-hoc analysis compared PPI use. Patients were PPI-naïve (N-PPI) if not on PPI during the study, and either early (E-PPI) or long-term PPI (LT-PPI) if on PPI at study entry or for at least ≥⅔ of treatment, respectively. PPI groups were not mutually exclusive. Results: Among 486 patients, 66.9 % were N-PPI, 13.2 % E-PPI, 18.7 % LT-PPI, and 11.5 % of the PPI users were defined as neither. Median PFS (mPFS) was 29.6 months in the study population, 28.7 months in N-PPI, 23.0 months in E-PPI (Hazard Ratio [HR] 1.5; 95%Confidence Interval [CI] 1.1–2.2; p = 0.024), and 23.0 months in LT-PPI (HR 1.4; 95%CI 1.0–1.9; p = 0.035). By landmark analysis, PPI use was associated with poorer mPFS at 3 and 12 months. Grade ≥3 hematological adverse events occurred in 71.7 % of N-PPI, 57.8 % of E-PPI (p = 0.021), and 54.9 % of LT-PPI (p = 0.003). Dose reductions and dosing delays due to hematological toxicity occurred in 70.8 % of N-PPI, 56.3 % of E-PPI (p = 0.018), and 52.7 % of LT-PPI (p = 0.002). Conclusions: PPI use may reduce palbociclib capsule toxicity, dose modifications, and clinical activity in HR+/HER2- ABC.

AbstractDocetaxel is one of the most valuable chemotherapeutic drugs, but it has extremely low oral bioavailability. In this study, an oral docetaxel delivery system was constructed based on the extract of Ganoderma lucidum, a well-known medicinal mushroom. First, a G. lucidum extract-docetaxel complex was prepared by stirring and freeze-drying. Results demonstrated that, compared to the docetaxel group, the exposure levels of docetaxel in the complex group were significantly increased in the mouse portal vein (Cmax, 599.7 vs. 58.5 ng/mL; AUC0–12 h, 631.2 vs. 185.9 ng·h/mL), systemic circulation (Cmax, 310.4 vs. 34.9 ng/mL; AUC0–12 h, 467.6 vs. 124.7 ng·h/mL), liver (Cmax, 431.2 vs. 58.4 ng/g liver; AUC0–12 h, 2007.3 vs. 473.0 ng·h/g liver), and lungs (Cmax, 1711.3 vs. 362.7 ng/g lung; AUC0–12 h, 5188.5 vs. 1329.5 ng·h/g lung). Moreover, in the complex group, except for metabolic stability (p > 0.05), transportation from the mucosal side of gut sacs to the serosal side (p < 0.01), solubility (52.6 vs. 4.2 μg/mL), and release of docetaxel in water were significantly improved (15 min, 5.5% vs. 2.3%; 8 h, 35.0% vs. 15.1%). Furthermore, scanning electron microscope (SEM), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) analysis demonstrated the amorphous existing form of docetaxel. In conclusion, the pharmacokinetics of oral docetaxel in mice was improved by the G. lucidum extract-docetaxel complex, which changed the existing form of docetaxel from crystalline to amorphous. This study provides a simple solution to docetaxel’s low oral bioavailability. [ABSTRACT FROM AUTHOR]

Trastuzumab is used to treat breast cancer patients overexpressing human epidermal growth factor receptor 2, but resistance and toxicity limit its uses, leading to attention to trastuzumab combinations. Recently, the synergistic effect of trastuzumab and H9 extract (H9) combination against breast cancer has been reported. Because drug exposure determines its efficacy and toxicity, the question of whether H9 changes trastuzumab exposure in the body has been raised. Therefore, this study aimed to characterize trastuzumab pharmacokinetics and elucidate the effect of H9 on trastuzumab pharmacokinetics at a combination dose that shows synergism in mice. As a result, trastuzumab showed linear pharmacokinetics after its intravenous administration from 1 to 10 mg/kg. In the combination of trastuzumab and H9, single and 2-week treatments of oral H9 (500 mg/kg) did not influence trastuzumab pharmacokinetics. In the multiple-combination treatments of trastuzumab and H9 showing their synergistic effect (3 weeks of trastuzumab with 2 weeks of H9), the pharmacokinetic profile of trastuzumab was comparable to that of 3 weeks of trastuzumab alone. In tissue distribution, the tissue to plasma ratios of trastuzumab below 1.0 indicated its limited distributions within the tissues, and these patterns were unaffected by H9. These results suggest that the systemic and local exposures of trastuzumab are unchanged by single and multiple-combination treatments of H9. [ABSTRACT FROM AUTHOR]

Both curcumin and naproxen possess the activity of pain relief, which makes it possible to co-administrate these drugs in the same prescription. This study aimed to assess the potential pharmacokinetic interaction of naproxen with curcumin in rats. Sprague-Dawley (SD) rats were orally administrated with naproxen (10 mg/kg body weight) and curcumin (10 or 20 mg/kg, body weight) synchronously or successively with a single administration of naproxen as the control group. The plasma concentration of naproxen was analyzed with liquid chromatography tandem mass spectrometry and the plasma concentration-time curve was established to obtain the pharmacokinetic parameters. In vitro, the metabolic stability of naproxen and the activity of CYP2C9 was assessed in rat liver microsome to reveal the potential mechanism. Both synchronous and successive co-administration of naproxen and curcumin induced increased maximum concentration (Cmax), area under the curve (AUC0-t), half-life (t1/2) and reduced clearance rate (CLF) of naproxen in rats, and the effect of curcumin was enhanced with its increasing concentration. In vitro, curcumin (10 and 20 mg/kg) was found to enhance the metabolic stability of naproxen (half-life from 29.7 ± 1.34 to 41.8 ± 5.07 and 46.9 ± 3.33 min) and significantly inhibited the activity of CYP2C9 with the IC50 of 16.36 μmol/L (P < 0.05). A combination of naproxen and curcumin would induce pharmacokinetic interaction, which increased the systemic exposure of naproxen. The concentration-dependent inhibition of CYP2C9 by curcumin was the potential mechanism underlying the drug-herb interaction.

ABSTRACT: This study investigates the combined effects of chitooligosaccharide (COS) and florfenicol (FLO) on the inhibition of Escherichia coli in vitro, as well as the pharmacokinetic interactions between these compounds in healthy chickens. The minimum inhibitory concentration (MIC) of COS and FLO alone and the fractional inhibitory concentration index (FICI) after combined treatment were determined using the broth microdilution method and checkerboard method, respectively. Additionally, we evaluated the pharmacokinetic interactions between the 2 types of COS and FLO in healthy chickens. Thirty chickens were randomly divided into 3 groups: Florfenicol group (30 mg/kg), COS J85 group (COS J85 20 mg/kg + florfenicol 30 mg/kg), COS H85 group (COS H85 20 mg/kg + florfenicol 30 mg/kg). Either FLO or COS was orally administered by gavage. The concentrations of FLO in chicken plasma were measured at different time points after the drug withdrawal using high-performance liquid chromatography (HPLC), and pharmacokinetic parameters were calculated by a compartmental method. The results showed that COS J85 and COS H85, when combined with FLO, had FICI values of 0.1875 to 0.75 and 0.3125 to 1, respectively, indicating good synergistic or additive effects against Escherichia coli. The pharmacokinetics of FLO alone and in combination with COS followed a 1-compartment model with first-order absorption and elimination. Furthermore, the pharmacokinetic analysis revealed that the elimination half-life (t1/2ke) of florfenicol was significantly increased in the COS H85 group compared to oral administration of florfenicol alone (P < 0.05). Other pharmacokinetic parameters did not show significant changes (P > 0.05), except between the 2 combined treatment groups, where statistical differences were observed for various parameters, excluding the area under the concentration-time curve from the time of dosing to infinity (AUC) and peak concentration (Cmax).

Acute respiratory distress syndrome (ARDS) is a critical form of acute lung injury (ALI). Here, we investigated the effect of a defined combination of ten pure phytochemicals in equal proportions of weight (NPM) from plants, recommended by Ayurveda for any protective action against lipopolysaccharide (LPS)-induced ALI. Results indicate that NPM markedly improved protein and neutrophil contents, myeloperoxidase and hydroxyproline levels, oxidative stress markers (glutathione and malonaldehyde), inflammatory cytokines, and genes (IL-6, TNF-α, TGF-β, and NF-κB/IκBα) in BALF/lung tissue. The histopathological examination of the lung revealed the shielding effect of NPM against ALI. NPM exhibited a protective effect on the lung by reducing oxidative stress and inhibiting inflammation. A substantial drop in favipiravir's oral exposure was observed in ALI-state compared to normal-state, but oral exposure upon NPM treatment in ALI-state followed similar behaviour of favipiravir alike normal-state without NPM treatment. Overall, results offer potential insight into Ayurvedic recommendations for immunity boosting during ALI situations. [ABSTRACT FROM AUTHOR]

S05590 is a fixed-dose combination of perindopril tert-butylamine 4 mg/indapamide 1.25 mg, and S06593 is a fixed-dose combination of perindopril arginine 5 mg/indapamide 1.25 mg/amlodipine 5 mg. The purpose of this study was to determine whether pharmacokinetic interactions exist among the components of S06593, compared with S05590 and amlodipine as reference drugs, in healthy Chinese male volunteers after a single oral administration under fasting conditions. A single-center, open-label, randomized, three-period, six-way crossover study was conducted. A total of 42 participants were enrolled and randomized to receive S05590 plus amlodipine, or S06593. The doses of perindopril were 3.34 mg in both S05590 and S06593, calculated as free acid. Blood samples were collected in each treatment period to determine the plasma concentrations of perindopril, indapamide and amlodipine, as well as perindoprilat, the main metabolite of perindopril. A total of 39 participants completed this study. The 90% confidence intervals of the geometric mean ratios of Cmax, AUC0-t and AUC0-∞ for perindopril, perindoprilat, indapamide and amlodipine were all within 80.00–125.00%, thus indicating that S05590 plus amlodipine and S06593 were pharmacokinetically equivalent. During the study, only one serious emergent adverse event was reported, which was deemed not to be associated with the study drug. No serious treatment-associated adverse events were observed.

Because of the high research and development cost of new drugs, the long development process of new drugs, and the high failure rate at later stages, combining past drugs has gradually become a more economical and attractive alternative. However, the ensuing problem of drug–drug interactions (DDIs) urgently need to be solved, and combination has attracted a lot of attention from pharmaceutical researchers. At present, DDI is often evaluated and investigated from two perspectives: pharmacodynamics and pharmacokinetics. However, in some special cases, DDI cannot be accurately evaluated from a single perspective. Therefore, this review describes and compares the current DDI evaluation methods based on two aspects: pharmacokinetic interaction and pharmacodynamic interaction. The methods summarized in this paper mainly include probe drug cocktail methods, liver microsome and hepatocyte models, static models, physiologically based pharmacokinetic models, machine learning models, in vivo comparative efficacy studies, and in vitro static and dynamic tests. This review aims to serve as a useful guide for interested researchers to promote more scientific accuracy and clinical practical use of DDI studies. [ABSTRACT FROM AUTHOR]

Recent studies have revealed that the combination therapy of atorvastatin (ATV) with naringenin (NG) can offer meaningful benefits in the treatment of hypercholesterolemia, while decreasing adverse side effects. To investigate whether there are pharmacokinetic interactions among ATV, its metabolite 2‐hydroxy atorvastatin (2‐ATV), and NG, in the current study, we developed and validated a simple, rapid, and specific UPLC–MS/MS method to simultaneously determine the concentrations of these analytes in the rat plasma. Sample preparation was performed using simple protein precipitation. Chromatographic analysis was carried out on an Acquity UPLC BEH C18 column (1.7 μm, 2.1 × 100 mm) using gradient elution mode, and these three analytes were detected using a Xevo® TQD triple quadrupole tandem mass spectrometer, in the positive ion electrospray ionization interface. The developed method showed good linearity over the following concentrations in rat plasma samples: 3–1200 ng/ml (r = 0.9965) for ATV, 1.5–600 ng/ml (r = 0.9934) for 2‐ATV, and 3–1200 ng/ml (r = 0.9964) for NG. The assays were validated and satisfied the acceptance criteria recommended by U.S. Food and Drug Administration guidelines. Upon successful application of the method to a pharmacokinetic interaction study, the results indicated that NG significantly enhanced the bioavailability of ATV and 2‐ATV. [ABSTRACT FROM AUTHOR]

Abstract Tuberculosis treatment consists of a drug combination, where isoniazid is the core drug and alcoholism is a factor highly related to poor patient compliance with the therapy. CYP2E1 is an enzyme involved both in the metabolism of ethanol and in the formation of hepatotoxic compounds during the metabolism of isoniazid. The shared metabolism pathway accounts for the possibility of pharmacokinetic interaction in cases of concomitant alcohol use during tuberculosis treatment. The aim of this study was to evaluate the effect of repeated exposure of Wistar rats (males, 250 g, n=6) to ethanol on the pharmacokinetics of a single dose of isoniazid in combination with pyrazinamide and rifampicin (100 mg/kg, 350 mg/kg and 100 mg/kg, respectively). An animal group received the combination of drugs and ethanol and was compared to a control group, which received the combination of drugs without exposure to ethanol. The plasma concentrations of isoniazid were determined by a UHPLC/UV bioanalytical method that was previously validated. Biochemical markers of liver function were measured to assess potential damage. A lower elimination half-life of isoniazid was observed in the ethanol group than in the control group (t1/2 0.91 h versus 1.34 h). There was no evidence of hepatotoxicity through the biomarker enzymes evaluated. The results allow us to infer that although there are no biochemical changes related to liver damage, there is a slight influence of ethanol exposure on the pharmacokinetic profile of isoniazid. This change may have a relevant impact on the efficacy of isoniazid in the outcome of tuberculosis treatment.

Drugs can only function as pharmaceuticals if they are accompanied by the necessary information for their proper use, such as efficacy and effect, dosage, and administration, as well as their potential side effects. This information may include unintended changes in drug efficacy or the development of side effects resulting from the use of two or more concomitant drugs, i.e., food- drug interactions. Such interactions also occur between meals, foods, or their constituents and pharmaceuticals. Drugs taken may potentially impact the function of nutrients or non-nutrients in foods (or both) or the nutritional status of humans. These occurrences are one of the critical issues for the safe and effective use of pharmaceuticals. Dietary intake itself markedly influences drug absorption by altering the physiology of the digestive system (including gastrointestinal peristalsis, secretion of digestive fluids, bile secretion, and blood flow). Additionally, wide variety of foods are consumed, and the ingredients include a diverse range of chemicals, including phytochemicals and other non-nutritive substances, in addition to nutrients. Moreover, even within the same food, the concentration of particular components it is expected to vary, depending on breed variety, area of production, and harvest season. Additionally, individual preferences also vary, hence the intake situation varies highly among individuals, influencing the type, combination, and quantity of foods consumed. Thus, information on food-drug interactions is extremely scarce, making proper assessment and management difficult. In this sense, food-drug interactions are the weakest link affecting the appropriate use of pharmaceuticals. Food-drug interactions are similar to drug-drug interactions since both medications and food components are chemical compounds. These interactions can be divided into pharmacokinetic and pharmacodynamic interactions. Pharmacokinetic interactions change the blood and tissue concentration of the drug during the absorption, distribution, metabolism, and excretion processes. Pharmacodynamic interactions are caused by the additive/synergic or antagonistic effects between the pharmacological action of a drug and the functionality of the food. Alternatively, the resulting interactions are not only detrimental, but are also beneficial, such as, reducing side effects. Furthermore, the nutritional status of the patient may influence the effectiveness of the drug or, conversely, the drug may influence the nutritional status. Thus, understanding the connection between medicine and diet is also crucial for appropriate drug usage. [ABSTRACT FROM AUTHOR]

Because of the high research and development cost of new drugs, the long development process of new drugs, and the high failure rate at later stages, combining past drugs has gradually become a more economical and attractive alternative. However, the ensuing problem of drug–drug interactions (DDIs) urgently need to be solved, and combination has attracted a lot of attention from pharmaceutical researchers. At present, DDI is often evaluated and investigated from two perspectives: pharmacodynamics and pharmacokinetics. However, in some special cases, DDI cannot be accurately evaluated from a single perspective. Therefore, this review describes and compares the current DDI evaluation methods based on two aspects: pharmacokinetic interaction and pharmacodynamic interaction. The methods summarized in this paper mainly include probe drug cocktail methods, liver microsome and hepatocyte models, static models, physiologically based pharmacokinetic models, machine learning models, in vivo comparative efficacy studies, and in vitro static and dynamic tests. This review aims to serve as a useful guide for interested researchers to promote more scientific accuracy and clinical practical use of DDI studies.

Context: Direct evidence of Triphala-drug interactions has not been provided to date. Objective: This study was aimed to determine the effects of Triphala on cytochrome P450 (CYP) isoforms and P-glycoprotein (P-gp) in vitro, and to investigate pharmacokinetic interactions of Triphala with CYP-probes in rats. Materials and methods: Effects of Triphala on the activities of CYP isoforms and P-gp were examined using human liver microsomes (HLMs) and Caco-2 cells, respectively. Pharmacokinetic interactions between Triphala and CYP-probes (i.e., phenacetin and midazolam) were further examined in rats. Results: Triphala extract inhibited the activities of CYP isoforms in the order of CYP1A2>3A4>2C9>2D6 with the IC50 values of 23.6 ± 9.2, 28.1 ± 9.8, 30.41 ± 16.7 and 93.9 ± 27.5 μg/mL, respectively in HLMs. It exhibited a non-competitive inhibition of CYP1A2 and 2C9 with the Ki values of 23.6 and 30.4 μg/mL, respectively, while its inhibition on CYP3A4 was competitive manner with the Ki values of 64.9 μg/mL. The inhibitory effects of Triphala on CYP1A2 and 3A4 were not time-dependent. Moreover, Triphala did not affect the P-gp activity in Caco-2 cells. Triphala, after its oral co-administration at 500 mg/kg, increased the bioavailabilities of phenacetin and midazolam by about 61.2% and 40.7%, respectively, in rats. Discussion and conclusions: Increases observed in the bioavailabilities of phenacetin and midazolam after oral co-administration of Triphala in rats provided a direct line of evidence to show Triphala-drug interactions via inhibition of CYP1A and CYP3A activities, respectively. These results, together with the lack of time-dependency of CYP 1A2 and 3A4 inhibition in vitro, suggested that the inhibitory effect of Triphala is primarily reversible.

Yu Kyong Kim,1,* Jun Gi Hwang,1,* Min Kyu Park1,2 1Department of Clinical Pharmacology and Therapeutics, Chungbuk National University College of Medicine and Hospital, Cheongju, Republic of Korea; 2Department of Pharmacology and Clinical Pharmacology, Dong-A University College of Medicine, Dong-A University Hospital, Busan, Republic of Korea*These authors contributed equally to this workCorrespondence: Min Kyu ParkDepartment of Clinical Pharmacology and Therapeutics, Chungbuk National University College of Medicine and Hospital, 776, 1 Sunhwan-ro, Seowon-gu, Cheongju-si, Chungcheongbuk-do, 28644, Republic of KoreaTel +82 43 269 8708Fax +82 43 269 8724Email mk_park@cbnuhctc.comPurpose: Combination therapy with insulin-independent sodium-glucose cotransporter 2 inhibitors and thiazolidinedione drugs, such as lobeglitazone, has been reported to elicit potential additive efficacy in glycemic control in type 2 diabetes mellitus. This study was conducted to evaluate the pharmacokinetic (PK) drug–drug interactions between empagliflozin and lobeglitazone in healthy subjects.Subjects and Methods: A randomized, open-label, multiple-dose study was conducted in 30 healthy subjects using a three-treatment, six-sequence, three-way crossover design. Subjects received one of the following treatments once daily for 5 days in each period: 25 mg empagliflozin, 0.5 mg lobeglitazone sulfate, or a combination. Serial blood sampling before every dose and up to 24 h after the last dose was performed during each treatment period. The PK parameters were estimated using noncompartmental methods with the plasma empagliflozin and lobeglitazone concentrations. The absence of a PK interaction was construed as the 90% confidence interval (90% CI) of maximum concentration at steady state (Cmax,ss) and area under the concentration-time curve over the dosing interval (AUCtau) for combination therapy-to-monotherapy ratios within the limits of 0.80– 1.25.Results: The steady-state plasma empagliflozin and lobeglitazone concentration-time profiles of combination therapy and monotherapy were comparable in the 25 subjects who completed the study. Coadministration of empagliflozin with lobeglitazone did not affect empagliflozin PK (with 90% CIs of 0.956– 1.150 and 0.945– 1.133 for Cmax,ss and AUCtau, respectively). Likewise, empagliflozin did not affect lobeglitazone Cmax,ss or AUCtau (with 90% CIs of 0.869– 0.995 and 0.851– 1.018, respectively). All treatment groups tolerated mild adverse events well.Conclusion: The lack of PK interactions between lobeglitazone and empagliflozin in combination therapy, along with their good tolerability, indicates that the two drugs can be coadministered without dose adjustment.Trial Registration Number: NCT02854748, Registered on August 7, 2016.Keywords: clinical trial, antidiabetic drug, pharmacokinetic interaction, thiazolidinedione, type 2 diabetes

The capsule formulation of CDK4/6 inhibitor palbociclib has reduced solubility at gastric pH > 4.5 and may have decreased activity when used with proton-pump inhibitors (PPI). Herein, we report the effect of PPI on palbociclib capsule activity and safety in the PARSIFAL study. First-line endocrine-sensitive, hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) patients received palbociclib capsules plus fulvestrant or letrozole. The primary endpoint was progression-free survival (PFS). This post-hoc analysis compared PPI use. Patients were PPI-naïve (N-PPI) if not on PPI during the study, and either early (E-PPI) or long-term PPI (LT-PPI) if on PPI at study entry or for at least ≥⅔ of treatment, respectively. PPI groups were not mutually exclusive. Among 486 patients, 66.9 % were N-PPI, 13.2 % E-PPI, 18.7 % LT-PPI, and 11.5 % of the PPI users were defined as neither. Median PFS (mPFS) was 29.6 months in the study population, 28.7 months in N-PPI, 23.0 months in E-PPI (Hazard Ratio [HR] 1.5; 95%Confidence Interval [CI] 1.1–2.2; p = 0.024), and 23.0 months in LT-PPI (HR 1.4; 95%CI 1.0–1.9; p = 0.035). By landmark analysis, PPI use was associated with poorer mPFS at 3 and 12 months. Grade ≥3 hematological adverse events occurred in 71.7 % of N-PPI, 57.8 % of E-PPI (p = 0.021), and 54.9 % of LT-PPI (p = 0.003). Dose reductions and dosing delays due to hematological toxicity occurred in 70.8 % of N-PPI, 56.3 % of E-PPI (p = 0.018), and 52.7 % of LT-PPI (p = 0.002). PPI use may reduce palbociclib capsule toxicity, dose modifications, and clinical activity in HR+/HER2- ABC. • Concomitant proton pump inhibitor and palbociclib was retrospectively analyzed. • Median progression-free survival was shorter with proton pump inhibitor use. • Adverse events and dose reductions were lower with proton pump inhibitors. • These results reveal proton pump inhibitors may interact with palbociclib capsules. [ABSTRACT FROM AUTHOR]

Dravet Syndrome (DS) is a severe developmental and epileptic encephalopathy. Fenfluramine recently demonstrated to be a highly efficacious and safe treatment option for DS patients. Fenfluramine has been recently approved by the FDA and EMA and is marketed as Fintepla®. DS and the need for additional anticonvulsive treatment options is discussed. The results of three placebo-controlled phase III studies (1 with and 2 without stiripentol) and 2 open label (extension) studies are reviewed. All studies demonstrate a consistent and impressive seizure reduction, confirming the results of two smaller investigator-initiated trials. The mechanism of action of fenfluramine is discussed. Finally, the place of fenfluramine in the future treatment of DS is outlined. Fenfluramine has a potent anticonvulsive effect in DS. Although not yet fully elucidated, the anticonvulsive mechanism of fenfluramine seems to be mainly serotonergic. Fenfluramine is generally well tolerated. A dose reduction is necessary in combination with stiripentol. Considering new competitors, efficacy seems lower for cannabidiol and is comparable with stiripentol. Preclinical studies indicate a disease specific action and possible disease modification in DS. The latter would support the use of fenfluramine above its anticonvulsive effect and needs to be further elaborated. [ABSTRACT FROM AUTHOR]

Introduction: Hyperammonemic encephalopathy (HAE) is a serious adverse effect of valproate semisodium, which is facilitated by the potential for drug interaction. However, despite frequent co-prescription of valproate semisodium and lithium, the role of this combination in the occurrence of HAE has not been defined in the literature. This case report concerns the occurrence of HAE concomitant with the initiation of lithium in a 29-year-old patient who had been placed on valproate semisodium for a schizoaffective disorder. Case Report: Due to a relapse while on a combined antipsychotic and mood-stabilizing therapy (paliperidone palmitate and valproate semisodium), a cross-taper from valproate semisodium to lithium was proposed. The initiation of lithium was accompanied by an acute confusional syndrome, an elevated serum valproate level and hyperammonemia suggestive of drug-induced HAE. The discontinuation of lithium and reduction of valproate semisodium led to neurological improvement, until a recrudescence of psychiatric symptoms justified a rechallenge of the combination within the framework of a new cross-taper. As soon as Lithium was re-initiated, an increase in the serum valproate level and hyperammonemia were again noted. Discussion: The mechanisms of valproate-related HAE involve various metabolic pathways. In this case, exploration of the iatrogenic hypothesis focused on the imputability of concomitant cannabis use and co-prescriptions of benzodiazepines, antipsychotics, and in all likelihood, mood stabilizers. Conclusion: Therefore, this case study suggests that Lithium plays a role in serum valproate level elevation, and supports the hypothesis of an association between an elevated serum valproate level, hyperammonemia and reversible encephalopathy. A more in-depth pharmacokinetic exploration would provide a better understanding of the mechanisms of these interactions and support for the benefit-risk balance associated with this frequent co-prescription. [ABSTRACT FROM AUTHOR]

IntroductionHyperammonemic encephalopathy (HAE) is a serious adverse effect of valproate semisodium, which is facilitated by the potential for drug interaction. However, despite frequent co-prescription of valproate semisodium and lithium, the role of this combination in the occurrence of HAE has not been defined in the literature. This case report concerns the occurrence of HAE concomitant with the initiation of lithium in a 29-year-old patient who had been placed on valproate semisodium for a schizoaffective disorder.Case ReportDue to a relapse while on a combined antipsychotic and mood-stabilizing therapy (paliperidone palmitate and valproate semisodium), a cross-taper from valproate semisodium to lithium was proposed. The initiation of lithium was accompanied by an acute confusional syndrome, an elevated serum valproate level and hyperammonemia suggestive of drug-induced HAE. The discontinuation of lithium and reduction of valproate semisodium led to neurological improvement, until a recrudescence of psychiatric symptoms justified a rechallenge of the combination within the framework of a new cross-taper. As soon as Lithium was re-initiated, an increase in the serum valproate level and hyperammonemia were again noted.DiscussionThe mechanisms of valproate-related HAE involve various metabolic pathways. In this case, exploration of the iatrogenic hypothesis focused on the imputability of concomitant cannabis use and co-prescriptions of benzodiazepines, antipsychotics, and in all likelihood, mood stabilizers.ConclusionTherefore, this case study suggests that Lithium plays a role in serum valproate level elevation, and supports the hypothesis of an association between an elevated serum valproate level, hyperammonemia and reversible encephalopathy. A more in-depth pharmacokinetic exploration would provide a better understanding of the mechanisms of these interactions and support for the benefit-risk balance associated with this frequent co-prescription.

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Soybeans [Glycine max (L.)] are a good source of isoflavones. The main isoflavone components of soybean are daidzein, genistein, and glycitein. World soybean production is very high. Because of its pharmacological activity, soy isoflavone intake over a long period of time may result in interactions with the drugs. This review summarizes soy isoflavone-drug interactions based on the pharmacokinetic parameters. Soy isoflavones have pharmacokinetic interactions with celecoxib, theophylline, paclitaxel, midazolam, imatinib, carbamazepine, valproic acid, repaglinide, omeprazole and danofloxacin. This is due to the changes in the area under the curve, maximum serum concentration, time that a drug is present at the maximum concentration in serum, clearance and half-life of the drugs when delivered together with soy isoflavones. The mechanisms of pharmacokinetic interactions occurs through the inhibition/induction of drug metabolizing cytochrome P450 (CYP450) enzymes such as CYP3A4, CYP2A1, and CYP2C9 or through the inhibition of drug transporters such as P-glycoprotein and breast cancer resistance protein. Thus, the consumption of soybean, soy isoflavones or soy products with drugs needs to be reconsidered. [ABSTRACT FROM AUTHOR]

Vortioxetine is currently used as the first-line therapy drug for major depressive disorder (MDD). In the present study, we aimed to develop and fully validate an ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of vortioxetine and its major metabolite Lu AA34443 in plasma and to investigate the effects of dronedarone and amiodarone on vortioxetine metabolism in rats. After protein precipitation with acetonitrile, the separation of vortioxetine, Lu AA34443 and duloxetine (internal standard, IS) were finished on an Acquity BEH C18 (2.1 mm × 50 mm, 1.7 μm) column and their detections were conducted by a Xevo TQ-S triple quadrupole tandem mass spectrometer in the positive ion mode. The assay displayed excellent linearity in the range of 0.5–50 ng/mL for vortioxetine, and 5–1000 ng/mL for Lu AA34443. The results of this method exhibited that the precision, accuracy, matrix effect, recovery, and stability of vortioxetine and Lu AA34443 met all requirements for the quantitation in plasma samples. The validated assay was further successfully employed to study the effects of dronedarone (80 mg/kg) and amiodarone (60 mg/kg) on vortioxetine metabolism in rats. The results showed that dronedarone and amiodarone could increase the concentration of vortioxetine and have inhibitory effect on vortioxetine metabolism. Thus, vortioxetine dose interruption or reduction may be considered.

Abstract Background Pharmacokinetic interaction is one of the most important indices for the evaluation of the compatibility of herbal medicines. Both Gancao (Glycyrrhizae Radix et Rhizoma) and Huanglian (Coptidis Rhizoma) are commonly used traditional Chinese medicines (TCMs). In this study, the influence of Gancao on the pharmacokinetics of Huanglian was systematically studied by using berberine as a pharmacokinetic marker. Methods Extracts of the herbal pieces of Huanglian and the herb pair (Huanglian plus Gancao) were prepared with boiling water. The concentration of berberine in the samples was analyzed using liquid chromatography-mass spectrometry. The total amounts of berberine in all extract samples were compared. Comparative pharmacokinetic studies of Huanglian and the herb pair were conducted in ICR mice. In vitro berberine absorption and efflux were studied using mice gut sacs. The equilibrium solubility of berberine in the extracts was determined. The in vitro dissolution of berberine was comparatively studied using a rotating basket method. Results Gancao significantly reduced berberine exposure in the portal circulation (425.8 ng·h/mL vs. 270.4 ng·h/mL) and the liver (29,500.8 ng·h/mL vs. 15,422.4 ng·h/mL) of the mice. In addition, Gancao decreased the peak concentration (Cmax) of berberine in the portal circulation (104.3 ng·h/mL vs. 76.5 ng·h/mL) and liver (4926.1 ng·h/mL vs. 2642.8 ng·h/mL) of mice. Significant influences of Gancao on the amount of berberine extracted (32% reduction), the solubility of berberine (34.7% compared with the control group), and dissolution (88.7% vs. 66.1% at 15 min in acid buffer and 68% vs. 51.8% at 15 min in phosphate buffer) were also revealed. Comparative pharmacokinetic studies in ICR mice indicated that the formation of sediment was unfavorable in terms of berberine absorption (345.3 ng·h/mL vs. 119.8 ng·h/mL). Conclusions Gancao was able to reduce intestinal absorption and in vivo exposure of berberine in Huanglian via the formation of sediment, which caused reductions in the extracted amount, solubility, and dissolution of berberine.

Many new chemical entities with tremendous therapeutic potential are discovered; yet, due to poor solubility and/or membrane penetration characteristics, many of these compounds have undesirable pharmacokinetic qualities. The latter is due to the lipid-like barrier imposed by epithelial mucosal layers, which drug molecules must cross to exert a therapeutic effect. Pre-systemic metabolic breakdown of drug compounds, primarily by cytochrome P450 enzymes found in intestinal enterocytes and liver hepatocytes, is another barrier. Although the nasal, buccal, and pulmonary modes of administration bypass the first-pass effect, systemic drug distribution is still reliant on drug molecules being absorbed via mucosal surfaces. Bio enhancers (naturally derived drug absorption enhancers) have been discovered to increase the amount of unaltered drug in the systemic blood circulation by regulating membrane permeability and/or pre-systemic metabolism. This paper attempts to give an overview of natural bio-enhancers and their key modes of action for medication administration via the nasal, buccal, pulmonary, and oral routes. Injections are frequently used to administer poorly bioavailable drugs, such as large, hydrophilic therapeutics. Bioenhancers may help patients by allowing for systemic distribution of these less bioavailable medications via alternative routes of administration (i.e., oral, nasal, buccal, or pulmonary routes of administration), as well as reducing dosages of tiny molecular pharmaceuticals and so lowering treatment costs. [ABSTRACT FROM AUTHOR]

Purpose: Comorbid conditions of heart and liver disorders added to HCV-induced hepatic steatosis make co-administration of statins, and direct-acting antivirals is common in clinical practice. This study aimed to evaluate the pharmacokinetic interaction of atorvastatin and fixed-dose combination of sofosbuvir/ledipasvir "FDCSL" with rationalization to the underlying mechanism. Methods: A randomized, three-phase crossover study that involves 12 healthy volunteers was performed. Participants received a single-dose of atorvastatin 80 mg alone, atorvastatin 80-mg plus tablets containing 400/90 mg FDCSL, or tablets containing 400/90 mg FDCSL alone. Plasma samples were analyzed using liquid chromatography–tandem mass spectrometry (LC–MS/MS) for atorvastatin, sofosbuvir, ledipasvir, and sofosbuvir metabolite "GS-331007," and their pharmacokinetics parameters were determined. Results: Compared to atorvastatin alone, the administration of FDCSL caused a significant increase in both areas under the concentration–time curve from time zero to infinity (AUC0−∞) and maximum plasma concentration (Cmax) of atorvastatin by 65.5% and 156.0%, respectively. Also, atorvastatin caused a significant increase in the AUC0−∞ and Cmax of sofosbuvir by 32.0% and 11.0%, respectively. Similarly, AUC0−∞ and Cmax of sofosbuvir metabolite significantly increased by 84.0% and 74.0%, respectively. However, ledipasvir AUC0−∞ showed no significant change after atorvastatin intake. The elimination rate in all drugs revealed no significant changes. Conclusion: After concurrent administration of FDCSL with atorvastatin, the AUC0−∞ of both atorvastatin and sofosbuvir were increased. Caution should be taken with close monitoring for possible side effects after co-administration of atorvastatin and FDCSL in clinical practice. [ABSTRACT FROM AUTHOR]

Silymarin is a mixture of flavonolignans isolated from the fruit of milk thistle (Silybum marianum (L.) Gaertner). Milk thistle extract is the active ingredient of several medications and dietary supplements to treat liver injury/diseases. After the oral administration, flavonolignans are extensively biotransformed, resulting in the formation of sulfate and/or glucuronide metabolites. Previous studies demonstrated that silymarin components form stable complexes with serum albumin and can inhibit certain cytochrome P450 (CYP) enzymes. Nevertheless, in most of these investigations, silybin was tested; while no or only limited information is available regarding other silymarin components and metabolites. In this study, the interactions of five silymarin components (silybin A, silybin B, isosilybin A, silychristin, and 2,3-dehydrosilychristin) and their sulfate metabolites were examined with human serum albumin and CYP (2C9, 2C19, 2D6, and 3A4) enzymes. Our results demonstrate that each compound tested forms stable complexes with albumin, and certain silymarin components/metabolites can inhibit CYP enzymes. Most of the sulfate conjugates were less potent inhibitors of CYP enzymes, but 2,3-dehydrosilychristin-19-O-sulfate showed the strongest inhibitory effect on CYP3A4. Based on these observations, the simultaneous administration of high dose silymarin with medications should be carefully considered, because milk thistle flavonolignans and/or their sulfate metabolites may interfere with drug therapy.

Introduction: Pharmacokinetic interaction of high-dose methotrexate (MTX) and other concomitantly administered renally secreted medicinal products may lead to insufficient methotrexate serum level decrease and significant MTX toxicity. Case report: We report the case of an 18-year-old male patient treated with high-dose MTX for an osteosarcoma and with high-dose piperacillin-tazobactam at the same time. MTX serum levels were severely elevated 24 hours after the MTX infusion and did not decrease in accordance with the specific calcium folinate rescue protocol. The patient experienced renal failure accompanied by neurological symptoms, most consistent with MTX-related renal and CNS toxicity. Management and outcome: After discontinuation of piperacillin-tazobactam, intensified calcium folinate rescue therapy, and IV hydration, the MTX serum levels decreased appropriately, and toxicity symptoms resolved. Discussion: Severe MTX-related toxicity, caused by drug-drug interaction, suggests that the concomitant use of high-dose MTX and high-dose piperacillin-tazobactam should be avoided generally. [ABSTRACT FROM AUTHOR]

CYP2E1 is directly or indirectly involved in the metabolism of ethanol and endogenous fatty acids but it plays a major role in the bio-activation of toxic substances that produce reactive metabolites leading to hepatotoxicity. Therefore, identification of CYP2E1 inhibitor from bioflavonoids class having useful pharmacological properties has dual benefit regarding avoidance of severe food-drug/nutraceutical-drug interaction and scope to develop a phytotherapeutics through an intended pharmacokinetic interaction. In the present study, we aimed to identify CYP2E1 inhibitor from experimental bioflavonoids which are unexplored for CYP2E1 inhibition till date using in-silico, in-vitro and in-vivo approaches. Results of in-vitro CYP2E1 inhibitory studies using CYP2E1-mediated chlorzoxazone 6-hydroxylation in human liver microsomes showed that glabridin have the highest potential than fisetin, epicatechin, nobiletin, and chrysin to inhibit CYP2E1 enzyme. Mechanistic investigations indicate that glabridin is a competitive CYP2E1 inhibitor. Molecular docking study results demonstrate that glabridin strongly interacted with the active site of human CYP2E1 enzyme. Pharmacokinetics of a CYP2E1 substrate in mice model indicates a significant alteration of chlorzoxazone and 6-hydroxychlorzoxazone plasma levels in the presence of glabridin. Further studies are needed to confirm the results at clinical level. Overall, glabridin is found to be a potential CYP2E1 inhibitor. [ABSTRACT FROM AUTHOR]