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Front Pharmacol ; 11: 585021, 2020.
Article in English | MEDLINE | ID: covidwho-1110321


In Feb 2020, we developed a physiologically-based pharmacokinetic (PBPK) model of hydroxychloroquine (HCQ) and integrated in vitro anti-viral effect to support dosing design of HCQ in the treatment of COVID-19 patients in China. This, along with emerging research and clinical findings, supported broader uptake of HCQ as a potential treatment for COVID-19 globally at the beginning of the pandemics. Therefore, many COVID-19 patients have been or will be exposed to HCQ, including specific populations with underlying intrinsic and/or extrinsic characteristics that may affect the disposition and drug actions of HCQ. It is critical to update our PBPK model of HCQ with adequate drug absorption and disposition mechanisms to support optimal dosing of HCQ in these specific populations. We conducted relevant in vitro and in vivo experiments to support HCQ PBPK model update. Different aspects of this model are validated using PK study from 11 published references. With parameterization informed by results from monkeys, a permeability-limited lung model is employed to describe HCQ distribution in the lung tissues. The updated model is applied to optimize HCQ dosing regimens for specific populations, including those taking concomitant medications. In order to meet predefined HCQ exposure target, HCQ dose may need to be reduced in young children, elderly subjects with organ impairment and/or coadministration with a strong CYP2C8/CYP2D6/CYP3A4 inhibitor, and be increased in pregnant women. The updated HCQ PBPK model informed by new metabolism and distribution data can be used to effectively support dosing recommendations for clinical trials in specific COVID-19 patients and treatment of patients with malaria or autoimmune diseases.

Drugs Real World Outcomes ; 8(2): 131-140, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1077714


BACKGROUND: Several pharmacological agents, such as chloroquine/hydroxychloroquine, have been promoted for COVID-19 treatment or pre-exposure prophylaxis. However, no comprehensive evaluation of the safety of these possible agents is available, and is urgently needed. OBJECTIVE: The purpose of this study was to investigate the risks of cardiac adverse events associated with the possible pharmacotherapies for COVID-19, including certain antimalarial, antiviral, and antibiotic drugs. PATIENTS AND METHODS: We conduced retrospective pharmacovigilance analyses of the US Food and Drug Administration Adverse Event Reporting System database. The reporting odds ratio (ROR), a data mining algorithm commonly used in pharmacovigilance assessment, was generated to quantify the detection signal of adverse events. RESULTS: Among individuals without coronavirus infection from 2015 Q1 to 2020 Q1, increased risks for cardiac disorders were found for antiviral agents such as chloroquine/hydroxychloroquine (ROR: 1.68; 95% confidence interval [CI] 1.66-1.70), lopinavir/ritonavir (ROR: 1.52; 95% CI 1.39-1.66), and antibiotics such as azithromycin (ROR: 1.37; 95% CI 1.30-1.44) and ceftriaxone (ROR: 1.92; 95% CI 1.80-2.05). Increased serious cardiac adverse events, including myocardial infarction, arrhythmia, and cardiac arrest, were also reported for these drugs. Further analyses of individuals with coronavirus infections revealed that 40% of individuals receiving chloroquine/hydroxychloroquine reported serious cardiac adverse events. Two cases resulted in QT prolongations and one case resulted in cardiac arrest. Chloroquine/hydroxychloroquine and azithromycin contributed to all the QT prolongation and cardiac arrest cases. CONCLUSIONS: The current pharmacotherapies for COVID-19 are associated with increased risks of cardiac adverse events. Variations in the cardiac safety profiles of these pharmacotherapies were also observed. Clinicians should closely monitor patients with COVID-19, especially those at high risk, using chloroquine/hydroxychloroquine and azithromycin.

Br J Clin Pharmacol ; 87(7): 2790-2806, 2021 07.
Article in English | MEDLINE | ID: covidwho-955646


AIMS: Hypertension is a common comorbidity of patients with COVID-19, SARS or HIV infection. Such patients are often concomitantly treated with antiviral and antihypertensive agents, including ritonavir and nifedipine. Since ritonavir is a strong inhibitor of CYP3A and nifedipine is mainly metabolized via CYP3A, the combination of ritonavir and nifedipine can potentially cause drug-drug interactions. This study provides guidance on nifedipine treatment during and after coadministration with ritonavir-containing regimens, using a physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) analysis. METHODS: The PBPK/PD models for 3 formations of nifedipine were developed based on the Simcyp nifedipine model and the models were verified using published data. The effects of ritonavir on nifedipine exposure and systolic blood pressure (SBP) were assessed for instant-release, sustained-release and controlled-release formulations in patients. Various nifedipine regimens were investigated when coadministered with or without ritonavir. RESULTS: PBPK/PD models for 3 formulations of nifedipine were successfully established. The predicted maximum concentration (Cmax ), area under plasma concentration-time curve (AUC), maximum reduction in SBP and area under effect-time curve were all within 0.5-2.0-fold of the observed data. Model simulations showed that the inhibitory effect of ritonavir on CYP3A4 increased the Cmax of nifedipine 17.92-48.85-fold and the AUC 63.30-84.01-fold at steady state and decreased the SBP by >40 mmHg. Thus, the combination of nifedipine and ritonavir could lead to severe hypotension. CONCLUSION: Ritonavir significantly affects the pharmacokinetics and antihypertensive effect of nifedipine. It is not recommended for patients to take nifedipine- and ritonavir-containing regimens simultaneously.

COVID-19 , HIV Infections , Antiviral Agents/therapeutic use , Area Under Curve , COVID-19/drug therapy , Drug Interactions , HIV Infections/drug therapy , Humans , Models, Biological , Nifedipine/pharmacology , Nifedipine/therapeutic use , Ritonavir/pharmacology , SARS-CoV-2
Acta Pharm Sin B ; 10(7): 1216-1227, 2020 Jul.
Article in English | MEDLINE | ID: covidwho-88718


Chloroquine (CQ) phosphate has been suggested to be clinically effective in the treatment of coronavirus disease 2019 (COVID-19). To develop a physiologically-based pharmacokinetic (PBPK) model for predicting tissue distribution of CQ and apply it to optimize dosage regimens, a PBPK model, with parameterization of drug distribution extrapolated from animal data, was developed to predict human tissue distribution of CQ. The physiological characteristics of time-dependent accumulation was mimicked through an active transport mechanism. Several dosing regimens were proposed based on PBPK simulation combined with known clinical exposure-response relationships. The model was also validated by clinical data from Chinese patients with COVID-19. The novel PBPK model allows in-depth description of the pharmacokinetics of CQ in several key organs (lung, heart, liver, and kidney), and was applied to design dosing strategies in patients with acute COVID-19 (Day 1: 750 mg BID, Days 2-5: 500 mg BID, CQ phosphate), patients with moderate COVID-19 (Day 1: 750 mg and 500 mg, Days 2-3: 500 mg BID, Days 4-5: 250 mg BID, CQ phosphate), and other vulnerable populations (e.g., renal and hepatic impairment and elderly patients, Days 1-5: 250 mg BID, CQ phosphate). A PBPK model of CQ was successfully developed to optimize dosage regimens for patients with COVID-19.