Sodium nitroprusside crystals are also of interest for optical storage. For this application, sodium nitroprusside can be reversibly promoted to a metastable excited state by blue-green light, and de-excited by heat or red light.In physiology research, sodium nitroprusside is frequently used to test endothelium-independent vasodilation. Iontophoresis, for example, allows local administration of the drug, preventing the systemic effects listed above but still inducing local microvascular vasodilation. Sodium nitroprusside is also used in microbiology, where it has been linked with the dispersal of Pseudomonas aeruginosa biofilms by acting as a nitric oxide donor. Analytical reagent
Sodium nitroprusside is also used as an analytical reagent under the name sodium nitroferricyanide for the detection of methyl ketones, amines, and thiols. It is also used as a catalyst in the quantitative determination of Ammonia in water samples via the Phenate Method. Ketones
The nitroprusside reaction is used for the identification of ketones in urine testing. Sodium nitroprusside was found to give a reaction with acetone or creatine under basic conditions in 1882. Rothera refined this method by the use of ammonia in place of sodium or potassium hydroxide. The reaction was now specific for methyl ketones. Addition of ammonium salts (e.g. ammonium sulfate) improved the sensitivity of the test, too.In this test, known as Rotheras test, methyl ketones (CH3C(=O)-) under alkaline conditions give bright red coloration (see also iodoform test). Rotheras test was initially applied to detecting ketonuria (a symptom of diabetes) in urine samples. This reaction is now exploited in the form of urine test strips (e.g. "Ketostix").
Sodium nitroprusside (SNP), sold under the brand name Nitropress among others, is a medication used to lower blood pressure. This may be done if the blood pressure is very high and resulting in symptoms, in certain types of heart failure, and during surgery to decrease bleeding. It is used by continuous injection into a vein. Onset is nearly immediate and effects last for up to ten minutes. It has been known to cause reflex tachycardia. It is often used as the vasodilator of choice in acute, emergency situations. The pharmacological activation is in relation to the release of nitric oxide which occurs from sodium nitroprusside which serves to activate Sodium Guanylyl Cyclase. Common side effects include low blood pressure and cyanide toxicity. Other serious side effects include methemoglobinemia. It is not generally recommended during pregnancy due to concerns of side effects. High doses are not recommended for more than ten minutes. It works by increasing nitric oxide levels in the blood, which increases cGMP levels in cells, and causes dilation of blood vessels.Sodium nitroprusside was discovered as early as 1850 and found to be useful in medicine in 1928. It is on the World Health Organizations List of Essential Medicines. Sodium nitroprusside is light sensitive, so it needs to be shielded from light to prevent degradation. Medical use
Sodium nitroprusside 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.