Lack of effect of physical exercise on pharmacokinetics of acetaminophen tablets in healthy subjects

The study was designed to evaluate the effect of physical exercise on the pharmacokinetics of acetaminophen. Ten healthy volunteers were drawn to the investigation. Each person was subjected to the pharmacokinetic study twice, i.e. at rest and on an exercise day. On the exercise day the subjects were performing 3 hours long physical exercise which consisted of a walk on a treadmill at 3 mph for 20 minutes of each half an hour. Acetaminophen was given orally at a single dose of 1.0 g prior to the exercise. Blood for pharmacokinetic assay was sampled within 24 hours following the drug administration. Acetaminophen concentrations were determined by the FPIA method. The total concentrations versus time curve were described by the one-compartment open model for extravascular administration. It was revealed, that the standard submaximal physical exercise does not affect the pharmacokinetics of acetaminophen statistically significantly.