Products
Nitroprusside is available as an infusion preparation in some countries (eg, Nitropress). It was approved in many countries in 2019. Nitroprusside is an old drug, developed in the 19th century and first used medically in the 1920s.
Structure and properties
Nitroprusside (Na2(Fe(CN)5NO) – 2H2O), Mr = 298.0 g/mol) is present in the drug as nitroprusside sodium, a reddish-brown powder that is soluble in water. It is a prodrug of nitric oxide (NO). Nitroprusside is a complex of iron (Fe2+) with 5 cyanide ions and nitric oxide.
Effects
Nitroprusside (ATC C02DD01) has vasodilator and antihypertensive properties. The effects are due to relaxation of vascular smooth muscle. This dilates the peripheral veins and arteries, resulting in a reduction in blood pressure and preload and afterload. The effect comes on quickly, after one to two minutes, and wears off as soon as the infusion is stopped. Nitroprusside has a short half-life in the range of minutes and is readily controllable.
Indications
- Acute hypertensive crises
- To reduce the risk of bleeding during surgery.
- Acute heart failure
Dosage
According to the professional information. The drug is administered as an intravenous infusion.
Contraindications
For complete precautions, see the drug label.
Adverse effects
Nitroprusside is a toxic agent. It reacts in the blood with hemoglobin in red blood cells, producing methemoglobin and cyanide, among other things. This blocks the transport of oxygen. Possible adverse effects include low blood pressure, methemoglobinemia, and the toxic effects of nitroprusside metabolites (including cyanide toxicity).