Comparative Pharmacology
Head-to-head clinical analysis: HYDRALAZINE HYDROCHLORIDE AND HYDROCHLOROTHIAZIDE versus TRICHLORMETHIAZIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HYDRALAZINE HYDROCHLORIDE AND HYDROCHLOROTHIAZIDE versus TRICHLORMETHIAZIDE.
HYDRALAZINE HYDROCHLORIDE AND HYDROCHLOROTHIAZIDE vs TRICHLORMETHIAZIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Hydralazine is a direct-acting arteriolar vasodilator that reduces peripheral vascular resistance via relaxation of vascular smooth muscle, possibly by interfering with calcium transport. Hydrochlorothiazide is a thiazide diuretic that inhibits the sodium-chloride symporter in the distal convoluted tubule, increasing excretion of sodium and water, and reducing plasma volume.
Inhibits sodium-chloride symporter in distal convoluted tubule, increasing excretion of sodium, chloride, and water.
Initially one capsule (25 mg hydralazine/25 mg hydrochlorothiazide, or 50 mg hydralazine/50 mg hydrochlorothiazide) twice daily, increase as needed to a maximum of 200 mg hydralazine/200 mg hydrochlorothiazide daily.
2-4 mg orally once daily; maximum 4 mg/day.
None Documented
None Documented
Clinical Note
moderateTrichlormethiazide + Digoxin
"The risk or severity of adverse effects can be increased when Trichlormethiazide is combined with Digoxin."
Clinical Note
moderateTrichlormethiazide + Digitoxin
"The risk or severity of adverse effects can be increased when Trichlormethiazide is combined with Digitoxin."
Clinical Note
moderateTrichlormethiazide + Deslanoside
"The risk or severity of adverse effects can be increased when Trichlormethiazide is combined with Deslanoside."
Clinical Note
moderateHydralazine: 2-8 hours (terminal, prolonged in renal impairment; acetylator phenotype affects clearance; slow acetylators have 2-fold longer half-life). Hydrochlorothiazide: 6-15 hours (terminal, prolonged in renal impairment; clinically relevant for once-daily dosing).
Terminal elimination half-life is approximately 2-6 hours (average 3.5 h); clinical context: short half-life necessitates once or twice daily dosing for sustained diuresis.
Hydralazine: 90% renal (primarily as metabolites, 10-15% unchanged); Hydrochlorothiazide: >95% renal (unchanged). Biliary/fecal: negligible for both.
Primarily renal (tubular secretion); ~70% excreted unchanged in urine; minor biliary/fecal (<10% total).
Category A/B
Category C
Thiazide Diuretic
Thiazide Diuretic
Trichlormethiazide + Acetyldigitoxin
"The risk or severity of adverse effects can be increased when Trichlormethiazide is combined with Acetyldigitoxin."