Comparative Pharmacology
Head-to-head clinical analysis: HYDRALAZINE HYDROCHLORIDE versus PRISCOLINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HYDRALAZINE HYDROCHLORIDE versus PRISCOLINE.
HYDRALAZINE HYDROCHLORIDE vs PRISCOLINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Vasodilation of arterioles by direct relaxation of vascular smooth muscle, likely involving interference with calcium movement.
Priscoline (tolazoline) is a competitive alpha-adrenergic receptor antagonist; also has direct vasodilatory and histamine-like effects, leading to peripheral vasodilation and decreased peripheral vascular resistance.
Oral: Initiate with 10 mg 4 times daily for 2-4 days, then increase to 25 mg 4 times daily for the remainder of the week, then titrate to 50 mg 4 times daily. Maximum daily dose: 300 mg. Intravenous: 5-20 mg IV bolus, may repeat every 20-30 minutes as needed, or continuous IV infusion 0.5-10 mg/hour.
10-50 mg subcutaneously or intramuscularly every 4-6 hours; intravenous administration (10 mg slow IV push) reserved for acute vasospastic episodes.
None Documented
None Documented
The terminal elimination half-life of hydralazine is approximately 2–4 hours in patients with normal renal function, but it is prolonged in renal impairment (up to 7–16 hours). The antihypertensive effect often lasts longer than the half-life due to persistent binding to arteriolar receptors.
Terminal elimination half-life is approximately 3-4 hours in adults; prolonged in renal impairment.
Hydralazine is primarily metabolized in the liver via N-acetylation (polymorphic) and hydroxylation. Less than 10% of the dose is excreted unchanged in urine. The major metabolites are hydralazine pyruvic acid hydrazone and other conjugates, which are excreted renally. Fecal elimination is negligible.
Primarily renal excretion of unchanged drug (approximately 90%); minor fecal excretion (<10%).
Category A/B
Category C
Vasodilator
Vasodilator