Pharmacokinetic Drug Interactions

Drugs labeled with stable isotopes have been successfully used in pharmacokinetic drug interaction studies. This technique provides precise information on the mechanisms responsible for drug interactions, e.g., changes in clearance due to induction or inhibition of drug metabolism, bioavailability, and volume of distribution. It offers the advantage that detailed studies on the pharmacokinetics and metabolism of a drug can be conducted in a clinical setting during steady-state conditions, thus avoiding problems in patient management that can arise from studies in which drug is withdrawn.