Studies on the clinical pharmacokinetics of imidazopyrazole

Plasma decay kinetics were analyzed for seven patients (400-5700 mg) during a Phase I clinical trial of imidazopyrazole. A two-compartment open pharmacokinetic model was able to account for the data. The median alpha-phase half-life was found to be 0.65 hour, with a median beta-phase half-life of 23.1 hours. Twelve per cent of the administered drug was excreted unchanged in 72 hours, whereas the total amount of imidazopyrazole equivalents excreted in that period was 38.6%. The median plasma equivalent space was found to be 15.9 l./m2, and volume of distribution at steady state was 40.2 l./m2. Renal and plasma clearance for imidazopyrazole was found to be 0.2 and 1.7 l./m2/hr, respectively.