Liposomal Amphotericin B (AmBisome) Pharmacokinetics Given as a Single Intravenous Dose to Obese Patients (ASPEN)

Overview

Dosing guidelines for liposomal amphotericin B (AmBisome) in (morbidly) obese patients are not available. Subsequently, the pharmacokinetic profile of AmBisome in this specific patient population is still largely unknown. To build a valid pharmacokinetic model, obese patients with a BMI ≥ 40 undergoing endoscopic gastric bypass surgery will receive a single dose of 1 mg/kg or 2 mg/kg AmBisome (besides standard anti-bacterial prophylaxis) and a PK-curve will be drawn. These PK-values can then be compared to the pharmacokinetics of a normal-weight group.

* The overall trial design is a prospective, open-label, non-randomized, single-centre, single-dose, multiple dose level trial, (1 mg/kg and 2 mg/kg). * A total of sixteen patients with a BMI ≥40 kg/m2 undergoing bariatric surgery who receive a pre-surgery dose of AmBisome 1 mg/kg (n=8) or 2 mg/kg (n=8) will be enrolled. * After enrollment of group 1 (1 mg/kg), an interim analysis on the safety of AmBisome will be performed before proceeding to group 2 (2 mg/kg). * Infusion time and concentration of AmBisome will be 45 minutes (1 mg/kg group) and 90 minutes (2 mg/kg group) * A PK curve will be determined after administration of a single, pre-surgery dose of AmBisome at t = 0.5, 0.75 (end of infusion group 1), 1.5 (end of infusion group 2), 2, 4, 6, 8, 10, 12, 24, 36, and 48 and (if feasible) 72 hours post infusion (n=12 samples) for group 1 (1 mg/kg), 8 patients.The PK curve of group 2 (2 mg/kg, 8 patients) will be similar to group 1, except for the t=1.5 hour sampling point, which will be end of infusion due to the infusion time of 90 minutes. * Patients are considered to have completed the study if at least 9/11 samples of the PK curve up until 48 hours have been collected. * Patients will be selected by the research team to have a good spread in weight bands.