Quinapril
Quinapril. ACE inhibitor prodrug — same conversion-to-active-form mechanism as enalapril / ramipril. Once-daily dosing for hypertension + heart… Oral half-life 1.2 h.
ACE inhibitor prodrug — same conversion-to-active-form mechanism as enalapril / ramipril. Once-daily dosing for hypertension + heart failure.
PK: Rojanasthien 2008 (PMID:18672641), 24 healthy volunteers, single 20 mg, verbatim "The half-life of quinapril (1.2 h)" and "the volume of distribution (Vd/F) of quinapril (1.1 L/kg)" (x 70 kg = 77 L). This record models the PARENT prodrug, matching its stored mw; the active species is quinaprilat (t1/2 1.8-1.9 h, Vd/F 0.3 L/kg in the same paper). F is pinned to 1 BECAUSE that volume is apparent (Vd/F) and already contains bioavailability; the measured absolute value is "approximately 50%" (Breslin 1996, PMID:8739020, IV quinaprilat vs oral quinapril), and applying it again would halve the true volume. ka dropped 2026-09-06: the stored 1.4 traces to quinaprilat's median tmax of "1.4 - 1.5 h" in the cited abstract, a time in hours, not a rate constant. Do NOT add a terminal accumulation phase — PMID:2144994 found "no accumulation between 2 and 7 days, even in severe renal impairment"; the 24 h duration of action is slow dissociation from tissue ACE, a PD effect with no matching plasma phase.
Pharmacokinetics
- Oral — t½ 1.2 h · F 100% · Vd 77 L
Sources: PMID:18672641, PMID:8739020, PMID:2144994