Metamizole: Current status of the safety and efficacy

Abstract

Metamizole is a nonsteroidal anti-infl ammatory drug, with analgesic, antipyretic, spasmo-lytic, and weak anti-infl ammatory properties. The analgesic eff ect of metamizole seems to be based on the inhibition of cyclooxygenase enzyme activity and stimulation of cannabi-noid receptors. Its use is still controversial, mainly due to agranulocytosis, metamizole-induced serious adverse reaction. While in many countries it is withdrawn from the market, in some countries metamizole is available as a medication prescribed for strictly defi ned indications, while in the others like Mexico, Brazil and China it can be obtained as an Over-The-Counter drug. The most common adverse eff ects of metamizole are the skin and subcutaneous tissue disorders. Metamizole appears to be of similar effi cacy to analgesics which are frequently used in the treatment of moderate to severe postoperative pain.