Hydralazine

Chemical

Hydrazinophthalazine

Hypertension

Tablets

Powder for reconstitution → NOT to be reconstituted with D5W because it degrades the drug quickly!

IV: 3 – 20mg every 30 mins

PO: 25mg QID

PO/IV

5 – 30 mins

?Unclear

Vascular smooth m → inhibits Ca²⁺ entry or prohibits intrac. Ca²⁺ store releases

CVS: ↓SVR, compensatory ↑HR

CNS: ↑CBF

GI: ↑RBF 2° ↑CO → ↑renin activity

Extensive 1^st pass

35% OBA

90% PPB

V_D = 4L/kg

Acetylation & oxidation, then conjugation

90% in urine

1% unchanged

t ½ B 0.5 – 3.5hrs