Vasodilator

Causes direct dilation of arterioles, increases contractility.
For treatment severe HTN if unresp to safer drugs
Side effects: Reflex tachycardia, Na+ and H2O retention (may need loop diuretics), hypertrichosis

Direct dilation of arterioles.
Side effects: orthostatic hypotension, systemic lupus erythematosus-like syndrome, reflex tachycardia, increased blood volume.
DDI with beta blockers and anti-HTN drugs

Vasodilator which releases nitric oxide, activates cellular cascade (similar to nitroglycerin)
For treatment of HTN emergencies (drug of choice)
Side effects: thiocyanate toxicity with prolonged use, cyanide poison if too fast, hypotension, reflex tachycardia

Other vasodilators