Name

hydralazine (Apresoline®)

Class

Antihypertensive - direct acting vasodilator

Description/Mechanism

Reduces BP mainly by direct effect on vascular smooth muscles of arterial-resisance vessels, resulting in vasodilation. Has little effect on venous capacitance vessels. Diastolic response is often greater than systolic. The vasodilation reduces PVR (afterload) and, therefore, significantly improves cardiac output, renal and cerebral blood flow. Hypotensive effect may be limited by sympathetic reflexes which increase heart rate and stroke volume.

Onset

IV: 5-30 min

IM: 10-40 minutes

Duration

2-6 hours

Indications

Hypertensive crisis

Hypertension associated with renal failure, pre-eclampsia and eclampsia

Contraindications

Compensatory hypertension (i.e. if the hypertension is the only thing maintaining cerebral perfusion)

Coronary artery disease

Dissecting aneurysm

Hypersensitivity

Adverse Reactions

Reflex tachycardia

Hypotension

Facial flushing

Headache

Diaphoresis

Anxiety

Nausea and vomiting

Drug Interactions

Concurrent use of diazoxide may result in severe hypotension.

Color changes may occur when given with glucose solutions.

Supplied

20 mg in 1ml ampule (20mg/ml)

Dose/Administration

Adult

IV/IM: 10-40 mg , may be repeated in 10 min.

Pediatric

IV/IM: 0.1 - 0.2 mg/kg/dose every 4-6 hr, may be repeated as needed.

Special Consideration

Pregnancy Safety: C

Blood pressure and ECG should be continuously monitored