Therapeutic Classification: antihypertensives
Pharmacologic Classification: vasodilators
Absorption: Rapidly absorbed following oral administration; well absorbed from IM sites. IV administration results in complete bioavailability.
Distribution: Widely distributed.
Metabolism/Excretion: Mostly metabolized by the GI mucosa and liver by N-acetyltransferase (rate of acetylation is genetically determined [slow acetylators have ↑ hydralazine levels and ↑ risk of toxicity; fast acetylators have ↓ hydralazine levels and ↓ response]).
Half-Life: 2–8 hr.
( antihypertensive effect)
| ROUTE | ONSET | PEAK | DURATION |
|---|
| PO | 45 min | 2 hr | 2–4 hr |
| IM | 10–30 min | 1 hr | 3–8 hr |
| IV | 5–20 min | 15–30 min | 2–6 hr |
