Pharmacokinetics of intravenous N-acetylcysteine in men at rest and during exercise

Abstract

Objective: We aimed to determine the pharmacokinetics (PK) of N-acetylcysteine (NAC) at rest and during exercise when given by continuous intravenous infusion intended to maintain relatively constant plasma concentrations. Methods: Plasma concentrations of NAC were measured in 24 healthy male subjects during and after a two-stage intravenous infusion designed to provide constant NAC concentrations during cycling exercise, including intense exercise to fatigue. Results: A three-compartment, open PK model was the best fit using population PK analysis with NONMEM. Whole-body clearance (CL) was 0.58 1 kg-1 h-1 (95% CI 0.44-0.72) for reduced NAC (NACR) and 0.16 (0.13-0.20) 1 kg-1 h-1 for total NA..