Comparative Pharmacology
Head-to-head clinical analysis: HYDRALAZINE AND HYDROCHLOROTHIAZIDE versus TRICHLORMAS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HYDRALAZINE AND HYDROCHLOROTHIAZIDE versus TRICHLORMAS.
HYDRALAZINE AND HYDROCHLOROTHIAZIDE vs TRICHLORMAS
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.
TRICHLORMAS is a sedative-hypnotic agent. Its mechanism of action is not fully understood but is believed to involve potentiation of GABAergic inhibition in the central nervous system, similar to other chloral derivatives. It is metabolized to trichloroethanol, which is the active hypnotic compound.
Oral: 1 tablet (hydralazine 25 mg / hydrochlorothiazide 25 mg) 1-2 times daily. Maximum: hydralazine 200 mg/day, hydrochlorothiazide 50 mg/day.
500 mg orally once daily at bedtime, increased as needed to a maximum of 1 g per day in divided doses; for insomnia, 1-2 g orally at bedtime.
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 is approximately 8-11 hours for the parent drug in adults with normal renal function. In patients with hepatic impairment, half-life may be prolonged up to 30 hours; in severe renal impairment, half-life of metabolites may increase significantly.
Hydralazine: 80-90% renal (mostly as metabolites), <10% unchanged. Hydrochlorothiazide: 95-99% renal (unchanged).
Primarily renal via glomerular filtration and tubular secretion; about 70-80% of the dose excreted unchanged in urine within 24 hours. The remainder is metabolized to trichloroethanol (active) and trichloroacetic acid; these metabolites are also eliminated renally.
Category A/B
Category C
Thiazide Diuretic
Thiazide Diuretic