Comparative Pharmacology
Head-to-head clinical analysis: QUINAPRIL HYDROCHLORIDE AND HYDROCHLOROTHIAZIDE versus VASOTEC.
Peer-Reviewed Evidence
Head-to-head clinical analysis: QUINAPRIL HYDROCHLORIDE AND HYDROCHLOROTHIAZIDE versus VASOTEC.
QUINAPRIL HYDROCHLORIDE AND HYDROCHLOROTHIAZIDE vs VASOTEC
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Quinapril is an ACE inhibitor that inhibits the conversion of angiotensin I to angiotensin II, reducing vasoconstriction and aldosterone secretion; hydrochlorothiazide is a thiazide diuretic that inhibits sodium reabsorption in the distal convoluted tubule, increasing excretion of sodium and water.
Enalaprilat, the active metabolite of enalapril, competitively inhibits angiotensin-converting enzyme (ACE), preventing conversion of angiotensin I to angiotensin II. This reduces vasoconstriction, aldosterone secretion, and sodium reabsorption, leading to decreased blood pressure and afterload.
Initial: 10/12.5 mg (quinapril/hydrochlorothiazide) orally once daily. Titrate based on response to a maximum of 40/25 mg once daily.
2.5 to 10 mg orally twice daily; initial dose 5 mg once daily; titrate based on blood pressure response; maximum 40 mg/day.
None Documented
None Documented
Quinaprilat terminal half-life ~25 hours (effective half-life ~12 hours); hydrochlorothiazide ~6-15 hours (increased in renal impairment).
Terminal half-life of enalaprilat is 35-38 hours, with multiple-dose half-life ~11 hours due to prolonged terminal phase; clinical context: once-daily dosing achieves steady-state in 3-4 days.
Renal excretion of quinaprilat (active metabolite) ~50-60% unchanged; hydrochlorothiazide ~70% unchanged. Biliary/fecal elimination accounts for <10% for both components.
Renal: 60-70% as enalaprilat; fecal: 20-30% as enalaprilat; biliary: minor (<10%).
Category D/X
Category C
ACE Inhibitor
ACE Inhibitor