Comparative Pharmacology
Head-to-head clinical analysis: HYDRALAZINE HYDROCHLORIDE W HYDROCHLOROTHIAZIDE 100 50 versus METAHYDRIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HYDRALAZINE HYDROCHLORIDE W HYDROCHLOROTHIAZIDE 100 50 versus METAHYDRIN.
HYDRALAZINE HYDROCHLORIDE W/ HYDROCHLOROTHIAZIDE 100/50 vs METAHYDRIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Hydralazine: Direct vasodilation of arterioles via unknown mechanism, possibly involving nitric oxide. Hydrochlorothiazide: Thiazide diuretic that inhibits the Na+/Cl- cotransporter in the distal convoluted tubule, increasing excretion of sodium and water.
Metahydrin (trichlormethiazide) is a thiazide diuretic that inhibits the sodium-chloride symporter (NCC) in the distal convoluted tubule of the nephron, reducing sodium and chloride reabsorption and increasing excretion of water, sodium, chloride, and potassium.
1 tablet (hydralazine 100 mg / hydrochlorothiazide 50 mg) orally once daily. Maximum: 1 tablet daily. Titrate from lower doses of individual components.
Oral, 50-100 mg once daily. Maximum 200 mg/day.
None Documented
None Documented
Hydralazine: 2-8 hours (prolonged in renal impairment); Hydrochlorothiazide: 6-15 hours (increased in renal impairment)
18-30 hours (clinically relevant for once-daily dosing in hypertension; prolonged in renal impairment)
Hydralazine: 90% renal metabolites, 10% feces; Hydrochlorothiazide: >95% renal (tubular secretion) as unchanged drug
Renal: 30% (fecal: 70% as unabsorbed drug, primarily biliary elimination; <1% unchanged in urine)
Category A/B
Category C
Thiazide Diuretic
Thiazide Diuretic