Comparative Pharmacology
Head-to-head clinical analysis: HYDRALAZINE AND HYDROCHLOROTHIAZIDE versus MICROZIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HYDRALAZINE AND HYDROCHLOROTHIAZIDE versus MICROZIDE.
HYDRALAZINE AND HYDROCHLOROTHIAZIDE vs MICROZIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Hydralazine is a direct-acting smooth muscle vasodilator that relaxes arterioles, reducing peripheral resistance. Hydrochlorothiazide is a thiazide diuretic that inhibits the sodium-chloride symporter in the distal convoluted tubule, increasing excretion of sodium and water.
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.
Oral: 1 tablet (hydralazine 25 mg / hydrochlorothiazide 25 mg) 1-2 times daily. Maximum: hydralazine 200 mg/day, hydrochlorothiazide 50 mg/day.
12.5-25 mg orally once daily for hypertension; 25-100 mg orally once daily for edema.
None Documented
None Documented
Hydralazine: 2-4 hours (fast acetylators), 4-8 hours (slow acetylators); extended in renal impairment. Hydrochlorothiazide: 6-15 hours; prolonged in renal impairment.
Terminal elimination half-life: 8-12 hours (prolonged in renal impairment; up to 30 hours in severe insufficiency).
Hydralazine: 80-90% renal (mostly as metabolites), <10% unchanged. Hydrochlorothiazide: 95-99% renal (unchanged).
Primarily renal (approximately 70% unchanged drug; remainder as metabolites and conjugates); minimal biliary/fecal (<10%).
Category A/B
Category C
Thiazide Diuretic
Thiazide Diuretic