Sodium nitroprusside

Intravenous
Heart failure

Intravenous
Hypertensive crisis

Intravenous
Induction of hypotension during anaesthesia

Dosage adjustments may be necessary.

Hypersensitivity, compensatory hypertension.

Hypothyroidism, renal and hepatic impairment, ischaemic heart disease, impaired cerebral circulation, elderly. Monitor blood thiocyanate concentration if treatment is longer than 3 days and should not exceed 100 mcg/ml. Monitor acid-base balance, venous oxygen concentration and BP. Caution to avoid extravasation. To be diluted with sterile dextrose 5% solution before infusion. Avoid sudden withdrawal. Leber's optic atrophy, low plasma-cobalamin concentrations, impaired pulmonary function. Pregnancy and lactation.

Nausea, retching, apprehension, headache, restlessness, muscle twitching, retrosternal discomfort; palpitation, dizziness, abdominal discomfort. Cyanosis and hypothyroidism (rare).

IV/Parenteral: C

Overdosage may result in excessive hypotension, cyanide or thiocyanate toxicity.

Additive effect when used with other antihypertensives. May prolong the fibrinolytic activity of alteplase. Risk of severe hypotension if used with phosphodiesterase inhibitors. May reduce serum digoxin levels.

Description: Sodium nitroprusside is a short-acting antihypertensive that acts directly on the venous and arteriolar smooth muscle causing peripheral vasodilation, thus decreasing peripheral resistance. It is also used to reduce preload and afterload in severe heart failure.
Pharmacokinetics:
Metabolism: Rapidly metabolised to cyanide in red blood cells and smooth muscle, leading to release of nitric oxide.
Excretion: Cyanide is further metabolised hepatically to thiocyanate and excreted in the urine. Plasma half-life of thiocyanate is about 3 days.

Store at 20-25°C.

Other Antihypertensives