Pharmacokinetic relationships between cinromide and its metabolites in the rhesus monkey I: 3-Bromocinnamamide, an active metabolite.

Fifty percent of a cinromide dose was metabolized to an active metabolite in the rhesus monkey. The steady-state concentration of this metabolite was 3-6 times that of the parent drug, depending on the route of administration. Cinromide is a medium-extraction ratio drug with a short half-life (0.92 +/- 0.23 hr) when compared with the active metabolite, which has a low extraction ratio and a longer half-life (4.43 +/- 0.76 hr). Incomplete oral bioavailability of cinromide is a result of first-pass metabolism rather than incomplete absorption.