Metamizole Sodium Monohydrate

Chemical properties

White or almost white, crystalline powder

The Uses of Metamizole Sodium Monohydrate

antibacterial

The Uses of Metamizole Sodium Monohydrate

Metamizol Sodium Monohydrate is used in methods of using Metamizole for treatment of Pyrexia in equines.

Definition

ChEBI: Sulpyrine is an organic molecular entity.

brand name

Diprofarn (Farmitalia, Societa Farmaceutici Italia, Italy); Novaldin (Sterling Winthrop).

General Description

Metamizole sodium is a nonsteroidal anti-inflammatory drug (NSAID). It is widely used as an analgesic and antipyretic agent.

Biochem/physiol Actions

Metamizole (Dipyrone) is a potent analgesic and antipyretic. Metamizole inhibits prostaglandin synthesis in both the periphery and the central nervous system. Metamizole may act as a prodrug. It is rapidly hydrolyzed to N-methyl-4-aminoantipyrine (MAA) and 4-aminoantipyrine (AA) which inhibit cyclo-oxygenase activity and can be further acylated with arachidonic acid forming compounds that bind to central and peripheral cannabinoid (CB1 and CB2) receptors and TRPV1 receptors. It is believed that these metabolites play a major role in metamizole activity. Metamizole has been withdrawn from clinical use in several countries because of a side-effect of agranulocytosis in some patients.

Clinical Use

Metamizol is the water soluble sodium sulfonate of amidopyrine. After oral application it is rapidly hydrolyzed to 4-methylaminoantipyrine and metabolized to various active metabolites . Metamizol has strong analgesic, spasmolytic, and antipyretic, but no anti-inflammatory properties. The exact mechanism of action is unknown but may include inhibition of prostaglandin synthesis. Inhibition of both COX isoenzymes by metamizol has been demonstrated only when very high concentrations of this drug were used, thus questioning the relevance of this activity.
COX inhibition may be induced by the metabolites, but this is not yet systematically investigated. Metamizol is used for the treatment of medium to severe pain, often in combination with opioids, for fever reduction and for the treatment of colic pain. It is given by mouth in doses of 500 mg up to 4 g daily, by intravenous or by rectal application. Metamizol is relatively free of acute side effects but in rare cases may cause severe and life-threatening allergic reactions like agranulocytosis, allergic skin reactions, and allergic shock. The compound is not used in the UK, USA, and in Scandinavian countries.