<unk>  is a vasodilator that is FDA approved for the treatment of hypertensive crisis and acute congestive heart failure. It is also indicated for producing controlled hypotension in order to reduce bleeding during surgery.. There is a Black Box Warning for this drug as shown here.  Common adverse reactions include excessive hypotension and cyanide toxicity.
Nitroprusside
Imolamine
Captopril
Milrinone
Balsalazide
Endralazine
Terodiline
Amrinone