Physiologically based pharmacokinetic modeling of candesartan to predict the exposure in hepatic and renal impairment and elderly populations

Background: Candesartan cilexetil is a widely used angiotensin II receptor blocker with minimal adverse effects and high tolerability for the treatment of hypertension. Candesartan is administered orally as the prodrug candesartan cilexetil, which is wholly and swiftly converted to the active metabolite candesartan by carboxylesterase during absorption in the intestinal tract. In populations with renal or hepatic impairment, candesartan's pharmacokinetic (PK) behavior may be altered, necessitating dosage adjustments. Objectives: This study was conducted to examine how the physiologically based PK (PBPK) model characterizes the PKs of candesartan in adult and geriatric populations and to predict the PKs of candesartan in elderly populations with renal and hepatic impairment. Design: After developing PBPK models using the reported physicochemical properties of candesartan and clinical data, these models were validated using data from clinical investigations involving various dose ranges. Methods: Comparing predicted and observed blood concentration data and PK parameters was used to assess the fit performance of the models. Results: Doses should be reduced to approximately 94% of Chinese healthy adults for the Chinese healthy elderly population; approximately 92%, 68%, and 64% of that of the Chinese healthy adult dose in elderly populations with mild, moderate, and severe renal impairment, respectively; and approximately 72%, 71%, and 52% of that of the Chinese healthy adult dose in elderly populations with Child-Pugh-A, Child-Pugh-B, and Child-Pugh-C hepatic impairment, respectively. Conclusion: The results suggest that the PBPK model of candesartan can be utilized to optimize dosage regimens for special populations. Plain language summary Develop a physiologically based pharmacokinetic model of candesartan to predict the exposure in Chinese elderly populations Background: Candesartan cilexetil is a widely used angiotensin II receptor blocker with minimal adverse effects and high tolerability for the treatment of hypertension. Candesartan cilexetil is wholly and swiftly converted to the active metabolite candesartan by carboxylesterase during absorption in the intestinal tract. Candesartan's pharmacokinetic behavior may be altered in patients with renal or hepatic impairment. Methods: We developed PBPK models using the reported physicochemical properties of candesartan and clinical data. We validated the PBPK models. Results: We found that the elderly population needs dosage adjustments. 1.Doses should be reduced to approximately 94% of Chinese healthy adults for the Chinese healthy elderly population 2.Doses should be reduced to approximately 92%, 68%, and 64% of that of the Chinese healthy adult dose in elderly populations with mild, moderate, and severe renal impairment 3.Doses should be reduced to approximately 72%, 71%, and 52% of that of the Chinese healthy adult dose in elderly populations with Child Pugh-A, Child Pugh-B, and Child Pugh-C hepatic impairment. Conclusion: The PBPK model of candesartan can be utilized to optimize dosage regimens for special populations.