Comparative Pharmacology
Head-to-head clinical analysis: CAPTOPRIL AND HYDROCHLOROTHIAZIDE versus HYDRO RX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CAPTOPRIL AND HYDROCHLOROTHIAZIDE versus HYDRO RX.
CAPTOPRIL AND HYDROCHLOROTHIAZIDE vs HYDRO-RX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Captopril is an angiotensin-converting enzyme (ACE) inhibitor that inhibits the conversion of angiotensin I to angiotensin II, resulting in vasodilation and decreased aldosterone secretion. Hydrochlorothiazide is a thiazide diuretic that inhibits the Na+/Cl- cotransporter in the distal convoluted tubule, increasing excretion of sodium and water.
Hydrochlorothiazide is a thiazide diuretic that inhibits the sodium-chloride symporter (NCC) in the distal convoluted tubule of the nephron, reducing sodium and chloride reabsorption, leading to increased diuresis, decreased plasma volume, and vasodilation. It also reduces peripheral vascular resistance.
1 tablet (captopril 25 mg / hydrochlorothiazide 15 mg) orally once daily, titrated up to a maximum of 1 tablet (captopril 50 mg / hydrochlorothiazide 25 mg) twice daily.
Initial: 25 mg orally once daily; may increase to 50 mg once daily after 2 weeks based on response. Maximum: 50 mg daily.
None Documented
None Documented
Captopril: ~2 hours (prolonged to 6-8 hours in heart failure or renal impairment). Hydrochlorothiazide: 5.6-14.8 hours (mean ~9.6 hours; prolonged in renal impairment).
Terminal elimination half-life is 8-12 hours in adults with normal renal function; extended to 20-30 hours in severe renal impairment (CrCl <30 mL/min).
Captopril: renal (95%), primarily as unchanged drug and disulfide metabolites. Hydrochlorothiazide: renal (≥95%) as unchanged drug via tubular secretion.
Renal excretion of unchanged drug accounts for 60% of elimination; biliary/fecal excretion accounts for 30%; 10% metabolized.
Category A/B
Category C
Thiazide Diuretic
Thiazide Diuretic