Population pharmacokinetics of intravenous and oral ciprofloxacin in children to optimize dosing regimens

Purpose This study aimed to characterize pharmacokinetics of intravenous and oral ciprofloxacin in children to optimize dosing scheme. Methods Children treated with ciprofloxacin were included. Pharmacokinetics were described using non-linear mixed-effect modelling and validated with an external dataset. Monte Carlo simulations investigated dosing regimens to achieve a target AUC 0-24 h /MIC ratio ≥ 125. Results A total of 189 children (492 concentrations) were included. A two-compartment model with first-order absorption and elimination best described the data. An allometric model was used to describe bodyweight (BW) influence, and effects of estimated glomerular filtration rate (eGFR) and age were significant on ciprofloxacin clearance. Conclusion The recommended IV dose of 10 mg/kg q8h, not exceeding 400 mg q8h, would achieve AUC 0-24 h to successfully treat bacteria with MICs ≤ 0.25 (e.g. Salmonella, Escherichia coli, Proteus, Haemophilus, Enterobacter, and Klebsiella). A dose increase to 600 mg q8h in children > 40 kg and to 15 mg/kg q8h (max 400 mg q8h, max 600 mg q8h if augmented renal clearance, i.e., eGFR > 200 mL/min/1.73 m 2 ) in children