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Abstract Background Therapeutic drug monitoring (TDM) is essential practice when dosing drugs with a narrow therapeutic index in order to achieve a plasma drug concentration within a narrow target range above the efficacy concentration but below the toxicity concentration. However, TDM with dose individualisation is challenging during a double-blind clinical trial with laboratory staff and investigators blinded to treatment arm allocation. Methods Drug concentrations were simulated for participants in the placebo arm by an unblinded independent statistician, utilising the measured values from the treatment arm participants. Simulated and actual concentrations were re-blinded and passed on to a dose-adjusting investigator, who made dose adjustment recommendations but was not directly responsible for clinical care of participants. Results A total of 257 sham lithium plasma concentrations were simulated utilising 242 true lithium plasma concentrations in real time as the trial progressed. The simulated values had a median (interquartile range) of 0.59 (0.46, 0.72) compared to 0.53 (0.39, 0.72) in the treatment arm. Blinding of the laboratory staff and dose-adjusting investigator was maintained successfully. Conclusions We succeeded in simulating sham lithium plasma concentrations while maintaining blinding. Our simulated values have a smaller range than the observed data, which can be explained by the challenges with respect to drug adherence and dose timing that were experienced. Trial registration Pan African Clinical Trials Registry, PACTR201310000635418 . Registered on 30 August 2013.

Advanced age and immunosuppressed states allow for complications of herpes zoster such as encephalitis. In this case report, we describe a patient with encephalopathy two days after initiation of antiviral therapy. After the necessary imaging and cerebrospinal fluid (CSF) analysis, it became evident that the neurological syndrome was due to acyclovir. Despite currently practised renal dose modification, the patient developed acyclovir-induced neurotoxicity and required intensification of his dialysis schedule to eliminate the drug. Acyclovir-induced neurotoxicity is a rare clinical presentation and presents a clinical dilemma to the physician who has to distinguish this entity from herpes zoster encephalitis and posterior circulation stroke. [ABSTRACT FROM AUTHOR]

Dolutegravir (DTG) has been introduced into first line combination antiretroviral therapy (ART) for HIV/AIDS. Penetration of ART into HIV reservoirs is essential to prevent continuous replication of HIV. However, accumulation of DTG in HIV reservoirs could be contributing to the adverse effects reported. We have developed and applied liquid chromatography tandem mass spectrometry (LC-MS/MS) methods to quantify DTG in wistar rat biological matrices following chronic DTG administration . DTG was detected using a Shimadzu 8040 triple quadrupole-mass spectrometer. The methods developed were in the concentration ranges of 17.5-8000 ng/mL for plasma and 15.5-16 680 ng/g for tissue matrices. Mean plasma DTG concentrations in the current study closely corresponded to plasma DTG levels reported in humans after chronic treatment. Plasma and tissue DTG concentrations were generally higher in females compared to male wistar rats, but these differences were nullified after correcting for body and organ size. Plasma DTG levels correlated with tissue DTG concentrations in the liver and gastrocnemius muscle tissue. Data suggest that body size - rather than sex - may be a major risk factor determining adverse outcomes of patients on the current DTG dosing strategy which does not account for differences in body mass. Furthermore, plasma DTG was not correlated with adipose tissue DTG concentration. This suggests that adipose may be a primary site for longer term inflammatory dysregulation and adverse outcome following DTG treatment., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests., (© 2023 The Authors.)

Recent cell-based and animal experiments have demonstrated an effective reduction in botulinum neurotoxin A (BoNT/A) by copper. Aim: We aimed to analyze whether the successful symptomatic BoNT/A treatment of patients with Wilson’s disease (WD) corresponds with unusually high doses per session. Among the 156 WD patients regularly seen at the outpatient department of the university hospital in Düsseldorf (Germany), only 6 patients had been treated with BoNT/A during the past 5 years. The laboratory findings, indications for BoNT treatment, preparations, and doses per session were extracted retrospectively from the charts. These parameters were compared with those of 13 other patients described in the literature. BoNT/A injection therapy is a rare (

Levothyroxine is the standard therapy for patients with hypothyroidism, a condition that affects up to 5% of people worldwide. While levothyroxine therapy has substantially improved the lives of millions of hypothyroid patients since its introduction in 1949, the complexity of maintaining biochemical and clinical euthyroidism in patients undergoing treatment with levothyroxine cannot be underestimated. Initial dosing of levothyroxine can vary greatly and may be based on the amount of residual thyroid function retained by the patient, the body weight or lean body mass of the patient, and thyroid-stimulating hormone levels. As levothyroxine is usually administered over a patient's lifetime, physiological changes throughout life will affect the dose of levothyroxine required to maintain euthyroidism. Furthermore, dose adjustments may need to be made in patients with concomitant medical conditions, in patients taking certain medications, as well as in elderly patients. Patients who have undergone any weight or hormonal changes may require dose adjustments, and the majority of pregnant women require increased doses of levothyroxine. Optimal treatment of hypothyroidism requires a partnership between patient and physician. The physician is tasked with vigilant appraisal of the patient's status based on a thorough clinical and laboratory assessment and appropriate adjustment of their levothyroxine therapy. The patient in turn is tasked with medication adherence and reporting of symptomatology and any changes in their medical situation. The goal is consistent maintenance of euthyroidism, without the patient experiencing the adverse events and negative health consequences of under- or overtreatment.Funding Merck.Plain Language Summary Plain language summary available for this article. [ABSTRACT FROM AUTHOR]

Background: The hepatotoxicity of acetaminophen is recognised worldwide. Unfavourable prognoses relating to overdose include liver transplantation and/or death. Several hepatotoxicity risk factors (HRFs) should motivate the adjustment of acetaminophen daily intake (to < 4 g/day): advanced age, weight < 50 kg, malnutrition, chronic alcoholism, chronic hepatitis B and C and HIV infection, severe chronic renal failure and hepatocellular insufficiency. Method: Over a 7-day period in Rennes University Hospital in December 2017, using DxCare® software, with an odds ratio estimation, we analysed all acetaminophen prescriptions, to assess to what extent the presence of HRFs altered the prescribers' choice of acetaminophen dose (< 4 g/day versus 4 g/day). Results: Among 1842 patients, considering only the first acetaminophen prescription, 73.7% were on 4 g/day. Almost half this population had at least 1 HRF. Whereas around 80% of the prescriptions in the < 4 g/day group were for patients with at least 1 HFR, only 53% of the prescriptions in the 4 g/day group concerned patients without HFRs (p < 0.001). Age > 75 and low weight were associated with the prescriber's choice of dose. Neither chronic alcoholism nor hepatocellular insufficiency influenced the acetaminophen doses prescribed. Conclusion: Considering the widespread use of acetaminophen and its favourable safety profile compared with other analgesic drugs, it appears urgent to remind prescribers of the maximum daily dose recommendations for acetaminophen for patients with HRFs, especially those with chronic alcoholism and hepatocellular insufficiency. [ABSTRACT FROM AUTHOR]

Background: 6‐Mercaptopurine (6‐MP) is considered the backbone of therapy in the maintenance phase of acute lymphoblastic leukemia (ALL). Gene polymorphisms involved in thiopurine degradation are predictors of toxicity in patients treated with 6‐MP. We investigated the effects of nucleoside diphosphate linked moiety X (nudix) type motif 15 (NUDT15) polymorphism NUDT15c.415C>T on neutropenia incidence, dose adjustment for 6‐MP, and survival rates in Thai children with ALL. Methods: Children diagnosed with ALL who received 6‐MP in the maintenance phase of treatment, in 2005–2016, were retrospectively enrolled. Results: The subjects consisted of 102 patients (median age, 5.2 years; 58 boys). On genetic testing 78, 22, and two patients were normal (CC), heterozygous (CT), and homozygous (TT), respectively. The incidence of neutropenia at 3 months was significantly higher in the CT/TT than CC polymorphism groups (OR, 12; 95%CI: 3.781–38.085, P < 0.001). The mean dose of 6‐MP at 3, 6, and 12 months was significantly lower in the CT/TT versus the CC group (P < 0.001). The 5 year overall survival (OS) rate for CC was 80.4%, and for CT/TT, 95.5% (P = 0.34). The 5 year event‐free survival (EFS) for CC and CT/TT was 75.1% and 85.7%, respectively (P = 0.17). After adjusted risk classification, no significant differences were observed for OS or EFS between the CC and CT/TT groups. Conclusion: Patients harboring the CT/TT polymorphism of NUDT15 had a significantly higher incidence of neutropenia during the first 3 months of maintenance, resulting in significantly lower doses of 6‐MP. [ABSTRACT FROM AUTHOR]

Immunoglobulin (IG) replacement therapy in patients with primary immunodeficiency diseases (PID) can be administered daily to every 2 weeks subcutaneously (SCIG) or every 3 or 4 weeks intravenously (IVIG). Develop a population pharmacokinetic (PK) model simulating IG exposure with Ig20Gly, a 20% SCIG; determine the dose adjustment factor for Ig20Gly relative to IVIG. Data from patients with PID treated with Ig20Gly and IVIG 10% were used to characterize IG population PK by nonlinear mixed-effects modeling and validated using data splitting and a visual predictive check. IG profiles were simulated for 1000 patients/interval treated with Ig20Gly (daily, every 2 days, every 3 days, twice weekly, weekly, every 2 weeks). An Ig20Gly adjustment factor of 130% was used to simulate Ig20Gly to IVIG AUC ratios for weekly or every 2 weeks Ig20Gly dosing intervals and a monthly IVIG dosing interval. A 1-compartment model, using weight as a covariate on clearance, derived from an index modeling dataset (n = 81) demonstrated predictability for a validation dataset (n = 21). The model estimate of bioavailability was 73.9%. Simulations for 6 dosing intervals showed similar mean profiles with overlapping prediction intervals. Mean AUC ratios of Ig20Gly to IVIG with a dose adjustment factor of 1.30:1 were 98.7% for weekly and 97.7% for twice-weekly administration demonstrating comparable exposure. Ig20Gly exposures from daily to up to every 2 weeks appeared equivalent. A 1.30 conversion factor provided coverage comparable to IVIG when Ig20Gly is administered daily to every 2 weeks. • A population PK model was derived from Ig20Gly and IVIG PK data from PID patients • Ig20Gly, a 20% subcutaneous IG therapy, model estimate of bioavailability was 73.9% • Ig20Gly exposure for varying dosing intervals (daily to every 2 weeks) was similar • A dose adjustment factor of 1.30 for Ig20Gly achieved exposure comparable to IVIG [ABSTRACT FROM AUTHOR]

Objective: To develop a pharmacokinetic-pharmacogenomic population model of morphine in critically ill children with acute respiratory failure.Design: Prospective pharmacokinetic-pharmacogenomic observational study.Setting: Thirteen PICUs across the United States.Patients: Pediatric subjects (n = 66) mechanically ventilated for acute respiratory failure, weight greater than or equal to 7 kg, receiving morphine and/or midazolam continuous infusions.Interventions: Serial blood sampling for drug quantification and a single blood collection for genomic evaluation.Measurements and Main Results: Concentrations of morphine, the two main metabolites, morphine-3-glucuronide and morphine-6-glucuronide, were quantified by high-performance liquid chromatography tandem mass spectrometry/mass spectroscopy. Subjects were genotyped using the Illumina HumanOmniExpress genome-wide single nucleotide polymorphism chip. Nonlinear mixed-effects modeling was performed to develop the pharmacokinetic-pharmacogenomic model. A two-compartment model with linear elimination and two individual compartments for metabolites best describe morphine disposition in this population. Our analysis demonstrates that body weight and postmenstrual age are relevant predictors of pharmacokinetic parameters of morphine and its metabolites. Furthermore, our research shows that a duration of mechanical ventilation greater than or equal to 10 days reduces metabolite formation and elimination upwards of 30%. However, due to the small sample size and relative heterogeneity of the population, no heritable factors associated with uridine diphosphate glucuronyl transferase 2B7 metabolism of morphine were identified.Conclusions: The results provide a better understanding of the disposition of morphine and its metabolites in critically ill children with acute respiratory failure requiring mechanical ventilation due to nonheritable factors. It also provides the groundwork for developing additional studies to investigate the role of heritable factors. [ABSTRACT FROM AUTHOR]

Purpose: In the randomized phase IIb LUX-Lung 7 trial, afatinib significantly improved progression-free survival (PFS) and time-to-treatment failure vs gefitinib in patients with treatment-naïve epidermal growth factor receptor mutation-positive non-small cell lung cancer. We report post hoc analyses of tolerability-guided dose adjustment for afatinib and summarize the clinical characteristics of patients who continued afatinib/gefitinib beyond initial radiological progression in LUX-Lung 7. Methods: Patients received afatinib 40 mg/day or gefitinib 250 mg/day until investigator-assessed progression or beyond if beneficial. In case of selected treatment-related adverse events (TRAEs), the afatinib dose could be reduced by 10-mg decrements to minimum 20 mg (only dose interruptions were permitted with gefitinib). Results: All randomized patients were treated (afatinib, n = 160; gefitinib, n = 159). Sixty-three patients had afatinib dose reduction (< 40 mg/day; 47 within first 6 months). Dose reduction decreased TRAE incidence/severity (before vs after; all grade/grade 3: 100.0%/63.5% vs 90.5%/23.8%). There was no evidence of significant difference in PFS for patients who received < 40 mg/day vs ≥ 40 mg/day for the first 6 months [median: 12.8 vs 11.0 months; hazard ratio 1.34 (95% confidence interval 0.90–2.00)]. Twenty-four and 26 patients continued afatinib and gefitinib, respectively, beyond progression in target lesions; median time from nadir of target lesion diameters to initial progression was 6.7 months and 5.6 months. Of these patients, ~ 70% had objective response or non-complete response/non-progressive disease in non-target lesions at initial progression. Conclusions: Protocol-defined dose adjustment of afatinib may allow patients to remain on treatment longer, maximizing clinical benefit even in the presence of radiological progression. [ABSTRACT FROM AUTHOR]

Background: Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma in elderly patients, and R-CHOP chemotherapy is the standard treatment protocol for DLBCL. Elderly patients (often defined as 75 years of age) are treated with anticancer drugs with precaution; however, the pharmacokinetics and pharmacodynamics (PK and PD) of these agents have not been thoroughly investigated in this population. In this study, we investigated the PK of cyclophosphamide (CP) and doxorubicin (DOXO) in elderly patients in order to verify if there is an influence of age on the PK of these anticancer drugs.Materials and Methods: This is a prospective multi-center clinical trial investigating the PK of CP and DOXO in elderly and very elderly patients with DLBCL treated by R-mini-CHOP regimen. Dose levels were 25 mg/m2, 0.7-1.4 mg/m2, 750 mg/m2, and 375 mg/m2 for DOXO, Vincristine (VCR), CP, and Rituximab, respectively. For PK analysis, 7 time point samples were collected over 48 h post-administration on cycle 3. CP and VCR plasma concentrations were measured using UPLC-MS/MS validated method. DOX plasma concentrations were measured using UPLC coupled with fluorescence detection-validated method. PK-POP modeling has been performed with a non-linear mixed-effect model program (Monolix).Results: 31 patients (15 males and 16 females), 75 to 96 years old, were treated with R-miniCHOP protocol. Among them, 19 patients were treated with VCR. A one-compartment (1cpt) open model with linear elimination adequately described CP concentration-time courses. The population PK parameters for CP were: CL = 3.58 L/h, Vmale = 32.2 L, and Vfemale = 28.7 L. Body weight (BW), albuminemia, and gender demonstrated a significant impact on CP PK. A 2-compartment (2cpt) open model with linear elimination best described DOXO concentration-time courses. The population PK parameters for DOXO obtained for the structural model were: CL = 51.1 L/h, Q = 49.6 L/h, V1 = 29.4 L, V2 = 1,130 L (clearances: CL, Q, volumes of distribution: V1, V2). The main covariate effects on DOXO PK were related to gender, BW, and VCR administration. VCR increases DOXO V1 from 29.4 L to 57.5 L (p = 0.02). No hematologic and cardiac grade 3 or 4 toxicity were recorded.Conclusions: Usually, in the absence of specific data, the majority of the physicians empirically reduce anticancer drug dose in the elderly patients (Tourani in J Geriatr Oncol 3(1): 41-48, 2012), or even does not treat these very-old patients. A better knowledge of the pharmacokinetics in very-old patients should allow a better dose adjustment based on the most significant physiological factors that modify the pharmacokinetic parameters. In this study, no serious toxicity was observed in these very elderly patients (84.1 years). This indicates that dose adjustment of chemotherapies should not only be based on age and creatinine clearance, but also, based upon appropriate physiological and biological data. Our findings indicate that, CP dose adjustment should be done according to serum albumin levels and patients BW and gender. [ABSTRACT FROM AUTHOR]

Background Early interventions with clinical decision support system (CDSS) guidance have ensured appropriate drug dosing for patients with renal impairment. However, the low rates of physician compliance with CDSS alerts have been reported. Objective We investigated whether designated pharmacist interventions were associated with physician' acceptance of the knowledge-based renal dosage adjustment system (K-RDS) for patients with reduced renal function. Setting A retrospective, single-center study was conducted using a healthcare information system at a tertiary teaching hospital. Methods This study compared physicians' acceptance of the K-RDS with and without designated pharmacists. The severity of prescription errors and the impact of service provided by the pharmacist were evaluated using the validated method developed by Overhage and Lukes. From April to June 2017, we enrolled patients who were ≥ 20 years of age and admitted with an estimated glomerular filtration rate under 50 ml/min on medications that required dose adjustments. Main outcomes measure The number of dosing alerts of the K-RDS and physicians' acceptance rates were compared between a control group guided by the central pharmacy only and a group with assigned designated pharmacists. The factors associated with the physicians' acceptance rate were also analyzed using a multivariate logistic regression method. The impact of service provided by the pharmacist were considered as 'highly significant' (categories: 1-2). Severity of prescription errors were defined as 'serious' if they corresponded to categories 1-2 of the Overhage and Lukes scale for severity, and interventions were relevant if they corresponded to categories 1-3 in the impact of  service provided by the pharmacist scale. Results Among 1363 prescription interventions, 491 (36.0%) were performed by designated pharmacists. The K-RDS alert acceptance rate by the physicians was 54.4% in the designated pharmacist group and 47.0% in the control group (p = 0.0233). The statistically significant association was found in the designated pharmacists group in 'highly significant' service provided by the pharmacist (p < 0.001, OR 1.772; 95% CI 1.362-2.305) and 'serious' severity of prescription errors (p = 0.012, OR 1.657; 95% CI 1.116-2.460). The presence of designated pharmacists (OR 1.353, p = 0.0272), patient's gender (OR 0.758, p = 0.0016), department specialty (OR 0.659, p < 0.0001), eGFR (OR 1.538 if < 10 ml/min; OR 1.519 if 10-40 ml/min, p < 0.0001), and medications (OR 6.058-43.992 depending on the medication category, p < 0.0001) were significant factors affecting physicians' acceptance. Conclusion Pharmacists' interventions effectively improved physicians' acceptance of the K-RDS alerts. [ABSTRACT FROM AUTHOR]

Purpose: Irinotecan is effective for metastatic colorectal cancer (mCRC). SN-38 is an active metabolite of irinotecan, which is formed by carboxylesterase and inactivated by UDP-glucuronyltransferase (UGT) 1A1. The UGT enzyme activity is reduced in patients with homozygous mutation in UGT1A1 genes (*6/*6, *28/*28 and *6/*28); thus dose reduction is required for prevention of severe adverse events associated with irinotecan. The present study was designed to investigate the relationship between UGT1A1 polymorphisms and the incidence of adverse events or the therapeutic effect in mCRC patients who received irinotecan.Methods: Sixty-three mCRC patients who received irinotecan during January 2014 and May 2018 were the subjects of this study. The incidence of adverse events, including diarrhea and neutropenia, and the therapeutic effect of irinotecan were compared among homozygous group, heterozygous group and wild-type group. The initial dose of irinotecan was 150 mg/m2 in the heterozygous group and wild-type group, while the dose was reduced by 20% (120 mg/m2) in the homozygous group.Results: The UGT1A1 polymorphisms occurred in 15.9%, 33.3%, and 50.8% for homozygous group, heterozygous group, and wild-type group, respectively. The average dose of irinotecan during overall cycles was not significantly different among three groups, despite the reduction of initial dose in homozygous group. There were no significant differences in the incidence rates of adverse events, tumor response, or time to treatment failure among three groups.Conclusion: The present study demonstrated that dose reduction by 20% ensured safety and efficacy of irinotecan in mCRC patients with homozygous mutation in UGT1A1 genes. [ABSTRACT FROM AUTHOR]

Abstract The pharmacokinetics (PK) and pharmacodynamics of many oral antidepressants (OADs) vary substantially among different genders and ethnicities. Likewise is their therapeutic effectiveness, time to response and the incidence of adverse drug events. The aim of this study is to compare the PK of four OADs (desvenlafaxine; DSV, venlafaxine; VLX, escitalopram; ESP, and agomelatine; AGT) among Egyptian males and females. In this study, LC-MS/MS methods were developed and validated for determining the four OADs in human plasma. Samples were prepared by liquid-liquid extraction. Chromatographic separation was performed on reversed-phase C 18 columns followed by positive-ion electrospray ionization and MS/MS detection. The assays were applied for the assessment of PK parameters in human volunteers (n = 95). The developed methods were linear, accurate, and precise for the determination of DSV, VLX, ESP and AGT with extraction recovery of 90 ± 2.0, 98 ± 1.0, 90 ± 1.3 and 87 ± 4.3%, respectively. OADs levels were successfully measured in subjects' plasma and PK parameters were calculated. A prevalent inter-individual variation in PK of the studied OAD was observed. The PK profile of DSV, VLX or ESP did not vary significantly between male and female subjects (p = 0.07–0.98; confidence level (CL) = 95) while the PK of AGT exhibited a significant gender-based variation in both the C max and the AUC ∞ (p = 0.047 and 0.0015; CL = 95). Our results highlight the significance of therapeutic drug monitoring of OADs. Further, it indicates the dose adjustment based on gender difference may not be relevant for DSV, VLX and ESP while it may be considered for AGT. Graphical abstract Unlabelled Image Highlights • Fast LC-MS/MS methods were developed for analysis of oral antidepressants (OADs). • The pharmacokinetic profiles of OADs were compared between men and women. • A significant inter-individual variation was observed for the analyzed OADs. • The pharmacokinetic profile of agomelatine was significantly different among men and women. [ABSTRACT FROM AUTHOR]

Background ODYSSEY OLE (NCT01954394) was an open-label extension (OLE) study for patients with heterozygous familial hypercholesterolemia (HeFH) who had completed previous phase 3 clinical trials with alirocumab. Alirocumab dose could be increased or decreased as per physician judgment. Objective To assess how the alirocumab dosing strategy was used by physicians during OLE. Methods Patients who entered OLE on a starting dose of alirocumab 75 mg every 2 weeks (Q2W) were included in the analysis (those from FH I, FH II, and LONG TERM trials). Those who completed LONG TERM entered an 8-week washout period before receiving alirocumab 75 mg Q2W at the start of OLE. From week 12, dose adjustment from 75 to 150 mg Q2W, or vice versa, was possible, based on the physician's clinical judgment. Results In total, 909 patients with HeFH completed the 3 parent studies and were treated during OLE for a duration of up to 40 months. Most patients (56.7%) were maintained on 75 mg Q2W throughout OLE, whereas 43.3% of patients had their dose increased to 150 mg Q2W. The dose was subsequently decreased in 7.4% of the patients in whom alirocumab was initially uptitrated. Overall, treatment-emergent adverse events were similar between those who had received placebo or alirocumab in the parent studies. Conclusions In the opinion of physicians, alirocumab 75 mg Q2W enabled over half of patients with HeFH to achieve sufficient low-density lipoprotein cholesterol lowering. Graphical abstract Highlights • In total, 909 patients with heterozygous familial hypercholesterolemia received alirocumab (median duration 2.5 years). • Alirocumab dose received (75 or 150 milligrams) based on clinical judgment of physician. • Seventy-five milligram dose considered enough for low-density lipoprotein cholesterol control for 56.7% of patients by physicians. • During open-label extension, 5.9% of patients reported local injection-site reaction adverse events. • Physician's decision to increase alirocumab dose was primarily due to high low-density lipoprotein cholesterol. [ABSTRACT FROM AUTHOR]

Abstract Objective To examine the laboratory anticoagulant effect of two thromboprophylactic low-molecular weight heparin (LMWH) regimens in post-cesarean obese patients. Methods A prospective cohort study, performed during 2017–2018 at a university hospital, of post-cesarean obese (>90 kg) patients receiving 40 mg/day (n = 30) or 60 mg/day (n = 30) enoxaparin, and a control group of non-obese (n = 30) post-cesarean patients receiving 40 mg/day enoxaparin. Thrombin generation and anti-Xa were measured twice on the third postoperative day: prior to and 3.5–4 h following the third LMWH dose. Results Age, parity, weight and body mass index were comparable between the obese study groups. Compared to the control non-obese group, the 40 mg obese and 60 mg obese groups showed increased baseline thrombin generation: medians 491, 581, 571 nM, respectively (P = 0.001 and P = 0.04, respectively). At peak LMWH activity, thrombin generation was higher in the 40 mg than in the 60 mg obese and control groups: medians 2599, 2391, 2229 nM, respectively (P = 0.01 and P < 0.0001, respectively); and thrombin generation was comparable between the 60 mg obese and the control groups (P = 0.58). Similarly, a significantly lower proportion of patients in the 40 mg obese group (10%) had anti-Xa levels within the recommended prophylactic range (0.2–0.5 IU/mL) than in the other groups (P < 0.0001 for both comparisons). Conclusion As determined by thrombin generation and anti-Xa testing, post-cesarean obese patients have an increased procoagulant potential, which was diminished only in those receiving higher dosages of LMWH. These findings support the need for clinical evaluation of LMWH dose adjustment in this setting. Highlights • A prospective study of 2 LMWH regimens in post-cesarean obese women. • Thrombin generation and anti-Xa levels were assessed. • Procoagulant potential was higher in post-cesarean obese women than in controls. • This was diminished only in those receiving higher LMWH dosage (60 vs. 40 mg/day). • Clinical evaluation of LMWH dose adjustment in postpartum obese patients is needed. [ABSTRACT FROM AUTHOR]

Background: The CYP2D6 enzyme is involved in the metabolism of numerous psychopharmacological drugs. Guidelines recommend how to adjust the dose of medication based on the CYP2D6 genotype.Aims: To evaluate the effect of dose adjustment to the CYP2D6 genotype and phenotype, in patients with severe mental illness (SMI) already receiving psychopharmacological treatment.Methods: A total of 269 psychiatric patients (on the island Curaçao) receiving antipsychotic treatment were genotyped for CYP2D6. Of these, 45 patients were included for dose adjustment according to the clinical guideline of the Royal Dutch Association for the Advancement of Pharmacy, i.e., 17 CYP2D6 poor metabolizers, 26 intermediate metabolizers, and 2 ultrarapid metabolizers. These 45 patients were matched for age, gender, and type of medication with a control group of 41 patients who were CYP2D6 extensive metabolizers (i.e., with a normal CYP2D6 function). At baseline and at 4 months after dose adjustment, subjective experience, psychopathology, extrapyramidal side-effects, quality of life, and global functioning were assessed in these two groups.Results: At baseline, there were no differences between the groups regarding the prescribed dosage of antipsychotics, the number of side-effects, psychiatric symptoms, global functioning, or quality of life. After dose adjustment, no significant improvement in these parameters was reported.Conclusion: In psychiatric patients with SMI already receiving antipsychotic treatment, dose adjustment to the CYP2D6 genotype or phenotype according to the guidelines showed no beneficial effect. This suggests that dose adjustment guidelines are currently not applicable for patients already using antipsychotics.ClinicalTrials.gov: Cost-effectiveness of CYP2D6 and CYP2C19 Genotyping in Psychiatric Patients in Curacao; Identifier: NCT02713672; https://clinicaltrials.gov/ct2/show/NCT02713672?term=CYP2D6&rank=5

The pharmacokinetic alteration of an antimicrobial medication leading to sub-therapeutic plasma level can aid in the emergence of resistance, a global threat nowadays. In this context, molnupiravir (prodrug of EIDD-1931) is the most efficacious orally against corona virus disease (COVID-19). In addition to drug-drug interaction, the pharmacokinetics of a drug can significantly vary during any disease state, leading to disease-drug interaction. However, no information is available for such a recently approved drug. Therefore, we aimed to explore the oral pharmacokinetics of EIDD-1931 in seven chemically induced disease states individually compared to the normal state using various rat models. Induction of any disease situation was confirmed by the disease specific study(s) prior to pharmacokinetic investigations. Compared to the normal state, substantially lowered plasma exposure (0.47- and 0.63-fold) with notably enhanced clearance (2.00- and 1.56-fold) of EIDD-1931 was observed in rats of ethanol-induced gastric injury and carbon tetrachloride-induced liver injury states. Conversely, paclitaxel-induced neuropathic pain and cisplatin-induced kidney injury states exhibited opposite outcomes on oral exposure (1.43- and 1.50-fold) and clearance (0.69- and 0.65-fold) of EIDD-1931. Although the highest plasma concentration (2.26-fold) markedly augmented in the doxorubicin-induced cardiac injury state, streptozocin-induced diabetes and lipopolysaccharide-induced lung injury state did not substantially influence the pharmacokinetics of EIDD-1931. Exploring the possible phenomenon behind the reduced or boosted plasma exposure of EIDD-1931, results suggest the need for dose adjustment in respective diseased conditions in order to achieve desired efficacy during oral therapy of EIDD-1931.

Voriconazole (VRZ) is a broad-spectrum antifungal medication widely used to treat invasive fungal infections (IFI). The administration dosage and blood concentration of VRZ are influenced by various factors, posing challenges for standardization and individualization of dose adjustments. On the one hand, VRZ is primarily metabolized by the liver, predominantly mediated by the cytochrome P450 (CYP) 2C19 enzyme. The genetic polymorphism of CYP2C19 significantly impacts the blood concentration of VRZ, particularly the trough concentration (Ctrough), thereby influencing the drug's efficacy and potentially causing adverse drug reactions (ADRs). Recent research has demonstrated that pharmacogenomics-based VRZ dose adjustments offer more accurate and individualized treatment strategies for individuals with hepatic insufficiency, with the possibility to enhance therapeutic outcomes and reduce ADRs. On the other hand, the security, pharmacokinetics, and dosing of VRZ in individuals with hepatic insufficiency remain unclear, making it challenging to attain optimal Ctrough in individuals with both hepatic insufficiency and IFI, resulting in suboptimal drug efficacy and severe ADRs. Therefore, when using VRZ to treat IFI, drug dosage adjustment based on individuals' genotypes and hepatic function is necessary. This review summarizes the research progress on the impact of genetic polymorphisms and hepatic insufficiency on VRZ dosage in IFI individuals, compares current international guidelines, elucidates the current application status of VRZ in individuals with hepatic insufficiency, and discusses the influence of CYP2C19, CYP3A4, CYP2C9, and ABCB1 genetic polymorphisms on VRZ dose adjustments and Ctrough at the pharmacogenomic level. Additionally, a comprehensive summary and analysis of existing studies' recommendations on VRZ dose adjustments based on CYP2C19 genetic polymorphisms and hepatic insufficiency are provided, offering a more comprehensive reference for dose selection and adjustments of VRZ in this patient population., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Li, Li, Zhang, Yu, Li, Zhou, Yang, Yang, Liu and Yang.)

Background: The CYP2D6 enzyme is involved in the metabolism of numerous psychopharmacological drugs. Guidelines recommend how to adjust the dose of medication based on the CYP2D6 genotype. Aims: To evaluate the effect of dose adjustment to the CYP2D6 genotype and phenotype, in patients with severe mental illness (SMI) already receiving psychopharmacological treatment. Methods: A total of 269 psychiatric patients (on the island Curaçao) receiving antipsychotic treatment were genotyped for CYP2D6. Of these, 45 patients were included for dose adjustment according to the clinical guideline of the Royal Dutch Association for the Advancement of Pharmacy, i.e., 17 CYP2D6 poor metabolizers, 26 intermediate metabolizers, and 2 ultrarapid metabolizers. These 45 patients were matched for age, gender, and type of medication with a control group of 41 patients who were CYP2D6 extensive metabolizers (i.e., with a normal CYP2D6 function). At baseline and at 4 months after dose adjustment, subjective experience, psychopathology, extrapyramidal side-effects, quality of life, and global functioning were assessed in these two groups. Results: At baseline, there were no differences between the groups regarding the prescribed dosage of antipsychotics, the number of side-effects, psychiatric symptoms, global functioning, or quality of life. After dose adjustment, no significant improvement in these parameters was reported. Conclusion: In psychiatric patients with SMI already receiving antipsychotic treatment, dose adjustment to the CYP2D6 genotype or phenotype according to the guidelines showed no beneficial effect. This suggests that dose adjustment guidelines are currently not applicable for patients already using antipsychotics. ClinicalTrials.gov: Cost-effectiveness of CYP2D6 and CYP2C19 Genotyping in Psychiatric Patients in Curacao; Identifier: NCT02713672; https://clinicaltrials.gov/ct2/show/NCT02713672?term=CYP2D6&rank=5 [ABSTRACT FROM AUTHOR]

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Background: Different methods have been proposed to analyze adverse events (AEs) associated with targeted therapies. While these AEs lead to dose adjustments for many patients, conventional reporting methods do not take drug administration into consideration. This paper underlines the importance of jointly reporting AEs and drug administration using prevalence, and proposes a complementary approach to reporting. Patients and methods: The prevalence method estimates the probability of progression-free patients being in a particular health state (state 1: AEs with full dose; state 2: AEs with reduced dose; state 3: no AEs with reduced dose) at different time points. To take into account the impact of dose adjustments on efficacy, the weighted prevalence method can be used by assigning utility weights to the different health states. The benefit of these methods was illustrated using data from a phase II trial of regorafenib. Results: Only 4.6% of progression-free patients developed mucositis/stomatitis (grade≤2) at 3 months. The prevalence of patients not experiencing this AE but whose dose was reduced or treatment interrupted was 58.1%. The weighted prevalence of the regorafenib toxicity profile and dose reduction was higher in the control arm. Conclusion: This case study confirms the importance of jointly analyzing AEs and drug administration. The weighted prevalence approach is an average score that incorporates the dimension of drug administration into AE assessment. This can be helpful for regulatory agencies as well as for clinicians to evaluate the benefit-risk ratio of therapies in their treatment choice. [ABSTRACT FROM AUTHOR]

Multiple myeloma (MM) is a plasma cell neoplasm that affects elderly individuals with two-thirds of patients over 65 years at diagnosis. However, data available are derived from clinical trials conducted in younger patients. Fewer studies investigated treatment options in the elderly. This review summarizes the clinical outcomes and toxicities associated with therapeutic regimens in older patients including doublet, triplet and high dose therapyin newly diagnosed patients and relapsed patients with MM. We highlight the importance of an approach tailored to individuals, incorporates the geriatric frailty assessment, considers comorbiditiess and commits to early recognition and management of toxicities ranging from myelosuppression to polypharmacy. To date, no trial has prospectively investigated a tailored treatment paradigm in older patients based on frailty and/or comorbidities. As the population ages, the proportion of MM patients with advanced age will grow. Studies are indicated to determine optimal treatment approaches in this increasingly heterogeneous geriatric population. [ABSTRACT FROM AUTHOR]

Amlodipine, a commonly prescribed anti-hypertensive drug, shows increased systemic exposure with cytochrome P450 (CYP) 3A inhibitors. Ritonavir (RTV) is a potent mechanism-based and reversible CYP3A inhibitor and moderate inducer that is used as a pharmacokinetic enhancer in several antiviral treatment regimens. Drug-drug interaction (DDI) between RTV and amlodipine is due to mixed inhibition and induction of CYP3A4, which is challenging to predict without a mechanistic model that accounts for the complexity of both mechanisms occurring simultaneously. A novel physiologically-based pharmacokinetic (PBPK) model was developed for amlodipine, and the model was verified using published clinical PK and DDI data. The verified amlodipine PBPK model was linked to a pharmacodynamics model that describes changes in systolic blood pressure (SBP) during and after co-administration with RTV. The magnitude and time course of RTV effects on amlodipine plasma exposures and SBP were evaluated, to provide guidance on dose adjustment of amlodipine during and after co-administration with RTV-containing regimens. Model simulations suggested that the increase in amlodipine’s plasma exposure by RTV diminishes by approximately 80% within 5 days after the last dose of RTV. PBPK simulations suggested that resuming a full dose of amlodipine [5 mg once daily (QD)] immediately after RTV’s last dose would decrease daily average SBP by a maximum of 3.3 mmHg, while continuing with the reduced dose (2.5 mg QD) for 5 days after the last dose of RTV would increase daily average SBP by a maximum of 5.8 mmHg. Based on these results, either approach of resuming amlodipine’s full dose could be appropriate when combined with appropriate clinical monitoring. [ABSTRACT FROM AUTHOR]