Dipyrone(CAS: 5907-38-0)

Metamizole (INN), or dipyrone (BAN, USAN), is a ampyrone sulfonate analgesic (pain reliever),

antispasmodic (spasm reliever) and antipyretic (fever reducer) similar to paracetamol in that it has

minimal anti-inflammatory effects and which is most commonly given orally or parenterally (by

injection) to prevent and treat pain related to surgery or for the treatment of acute pain. It was first

introduced into clinical use inGermanyin 1921 and for many years it was available over-the-counter

in most countries, until its toxicities became so readily apparent, although in some countries it is

available over-the-counter, its use is usually restricted in developed countries, due to its potential

for causing toxic reactions.

Metamizole is marketed under various trade names, including Algozone, Algocalmin, Algopyrin,

Analgin, Dipirona, Novalgin, Neo-Melubrina and Optalgin . Metamizole has been used for decades

in many European (excluding the UK, but including most of continental Europe, including Germany,

Italy, Russia,Spain and Turkey), Asian (China, India, Indonesia and Thailand included), African

(including South Africa) and South American (including Argentina andBrazil) countries, despite this,

it has been found to have a potentially fatal side effect of agranulocytosis (a dangerously compromised

immune system; its rate varies significantly country-to-country), aplastic anaemia and hypersensitivity

reactions (like allergic reactions such as anaphylaxis).

Medical uses

It is primarily used for perioperative pain, although the clinical trial data to support this use is limited at

best. It is also used for acute injury, colic, cancer pain, other acute/chronic forms of pain and high fever

unresponsive to other agents.

Special populations

Its use in pregnancy is advised against, although animal studies are reassuring in that they show minimal

risk of birth defects; its use in the elderly or those with liver/kidney impairment is advised against, but if

these groups of people must be treated a lower dose and caution is usually advised; its use in lactation is

advised against as it is excreted in breast milk.