<unk>  is intravenously infused in cases of acute hypertensive crises. Its effects are usually seen within a few minutes. Nitric oxide reduces both total peripheral resistance and venous return, thus decreasing both preload and afterload. So, it can be used in severe congestive heart failure where this combination of effects can act to increase cardiac output. In situations where cardiac output is normal, the effect is to reduce blood pressure. It is sometimes also used to induce hypotension (to reduce bleeding) for surgical procedures (for which it is also FDA, TGA, and MHRA labelled). The medication is extremely beneficial for use in medical patients because the effects of the medication will directly stop the second that it stops being infuse. This is due to the metabolism of the drug, and the rapid inactivation to thiocyanin once conversion of the drug stops. This compound has also been used as a treatment for aortic valve stenosis, oesophageal varices, myocardial infarction, pulmonary hypertension, respiratory distress syndrome in the newborn, shock, and ergot toxicity.
Sodium nitroprusside
Balsalazide
Adenosine
Ergotamine
Isoprenaline
Dobutamine
Nitroglycerin 
Labetalol