Vasodilator Antihypertensive Drugs

Hydralazine:

Indications: moderate to severe hypertension (adjunct); heart failure (with long-acting nitrate), hypertensive crisis (including during pregnancy)

Contraindications: Hypersensitivity to hydralazine; coronary artery disease; mitral valvular rheumatic heart disease.

Dose and Administration: By slow intravenous injection, hypertension with renal complications and hypertensive crisis, 5–10 mg diluted with 10 mL sodium chloride 0.9%; may be repeated after 20–30 minutes. By intravenous infusion, hypertension with renal complications and hypertensive crisis, initially 200– 300 micrograms/minute; maintenance usually 50–150 micrograms/minute

Sodium Nitroprusside:

Indications: Sodium nitroprusside is indicated for the immediate reduction of blood pressure of patients in hypertensive crises. Concomitant longer-acting antihypertensive medication should be administered so that the duration of treatment with sodium nitroprusside can be minimized. also indicated for producing controlled hypotension in order to reduce bleeding during surgery. also indicated for the treatment of acute congestive heart failure.

Contraindications: Sodium nitroprusside should not be used in the treatment of compensatory hypertension, where the primary hemodynamic lesion is aortic coarctation or arteriovenous shunting. should not be used to produce hypotension during surgery in patients with known inadequate cerebral circulation. should not be used for the treatment of acute congestive heart failure associated with reduced peripheral vascular resistance such as high-output heart failure that may be seen in endotoxic sepsis.

Dose and Administration:  Hypertensive crisis, by intravenous infusion, initially 0.5–1.5 micrograms/kg/minute, then increased in steps of 500 nanograms/kg/minute every 5 minutes within      range   0.5–8 micrograms/kg/minute (lower doses if already receiving other antihypertensives); stop if response unsatisfactory with max. dose in 10 minutes.