Comparative Pharmacology
Head-to-head clinical analysis: HYDRALAZINE HYDROCHLORIDE W HYDROCHLOROTHIAZIDE 50 50 versus MICROZIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HYDRALAZINE HYDROCHLORIDE W HYDROCHLOROTHIAZIDE 50 50 versus MICROZIDE.
HYDRALAZINE HYDROCHLORIDE W/ HYDROCHLOROTHIAZIDE 50/50 vs MICROZIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Hydralazine is a direct-acting vasodilator that relaxes arteriolar smooth muscle via mechanisms involving interference with calcium ion movement and possibly nitric oxide release. Hydrochlorothiazide is a thiazide diuretic that inhibits the sodium-chloride symporter in the distal convoluted tubule, reducing sodium and water reabsorption and decreasing plasma volume.
Inhibits the sodium-chloride symporter (NCC) in the distal convoluted tubule of the nephron, reducing reabsorption of sodium and chloride, leading to increased excretion of water and electrolytes, and a decrease in blood volume and peripheral vascular resistance.
1 tablet (hydralazine 50 mg/hydrochlorothiazide 50 mg) orally twice daily, maximum 2 tablets daily.
12.5-25 mg orally once daily for hypertension; 25-100 mg orally once daily for edema.
None Documented
None Documented
Hydralazine: 2-8 hours (acetylator phenotype dependent; slow acetylators up to 8h, fast acetylators 1-2h). Hydrochlorothiazide: 6-15 hours (mean 10h).
Terminal elimination half-life: 8-12 hours (prolonged in renal impairment; up to 30 hours in severe insufficiency).
Hydralazine: 80% renal (mainly as metabolites, 1-2% unchanged), 10% fecal. Hydrochlorothiazide: >95% renal (unchanged) via organic anion transporters.
Primarily renal (approximately 70% unchanged drug; remainder as metabolites and conjugates); minimal biliary/fecal (<10%).
Category A/B
Category C
Thiazide Diuretic
Thiazide Diuretic