Population pharmacokinetics of lisinopril in hypertensive children and adolescents with normal to mildly reduced kidney function

Aims Lisinopril, an angiotensin‐converting enzyme inhibitor, is a frequently prescribed antihypertensive drug in the paediatric population, while being used off‐label under the age of 6 years in the USA and for all paediatric patients globally. The SAFEPEDRUG project (IWT‐130033) investigated lisinopril pharmacokinetics in hypertensive paediatric patients corresponding with the day‐to‐day clinical population. Methods The dose‐escalation pilot study included 13 children with primary and secondary hypertension who received oral lisinopril once daily in the morning; doses ranged from 0.05 to 0.2 mg kg −1 . Patients were aged between 1.9 and 17.9 years (median 13.5 years) and weight ranged between 9.62 and 97.2 kg (median 53.2 kg). All data were analysed using Monolix version 2020R1 (Lixoft, France) and R version 3.6.2. Results A 1‐compartment model with first‐order absorption and first‐order elimination optimally describes the data. Parameter estimates of absorption rate constant (0.075 h −1 [0.062, 0.088], typical value [95% confidence interval]), volume of distribution (31.38 L 70 kg −1 [10.5, 52.3]) and elimination clearance (24.2 L h −1 70 kg −1 [19.5, 28.9]) show good predictive ability. Significant covariate effects include total body weight on elimination clearance, and distribution volume and estimated glomerular filtration rate (eGFR) on elimination clearance. The effects of eGFR on the elimination clearance are optimally described by a linear effect centred around 105 mL min −1 1.73 m −2 . The effects of body weight were implemented using fixed allometric exponents centred around an adult weight of 70 kg. Conclusion Lisinopril dose and regimen adjustments for paediatric patients should include eGFR on top of weight adjustments. An expanded model characterizing the pharmacodynamic effect is required to identify the optimal dose and dosing regimen.