Single intravenous dose and steady-state oral dose pharmacokinetics of nicardipine in healthy subjects.
Nicardipine HCl oral doses (10-40 mg) were administered sequentially to six healthy subjects. For each regimen the capsule dose was administered every 8 hours (q 8 h) for 3 days and the plasma profiles of nicardipine and its pyridine analogue (M5) were determined following the last dose on day 4. Steady-state plasma concentrations of nicardipine for each subject were fitted very well by the Michaelis-Menten equation. An intravenous tracer dose (0.885 mg nicardipine HCl) was administered simultaneously with the final oral dose on the fourth day of the 30 mg q 8 h regimen. The steady-state bioavailability of nicardipine was shown to be dose-dependent and averaged 19 per cent (10 mg), 22 per cent (20 mg), 28 per cent (30 mg), and 38 per cent (40 mg). Nicardipine undergoes linear first-pass metabolism to M5. Other metabolic pathways are responsible for the saturable first-pass metabolism observed for nicardipine.
D000284:Administration, Oral; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D009529:Nicardipine / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*
D009529:Nicardipine