May 25, 2021
Dipyrone (Metamizole): A Toxic Adulterant Found in Illicit Street Drugs
Dipyrone is a non-opioid analgesic with antipyretic activity, which was developed by the German company Hoechst AG in 1920 with mass production starting in 1922. It is a pro-drug, which is rapidly metabolized after oral administration to active pyrazolone compounds. Dipyrone is also know under different generic names such as metamizole, noramidopyrine, and others. Dipyrone was sold as an over-the-counter (OTC) analgesic until the 1970s, at which time it was banned in several countries, including the United States, several European nations, Japan, and Australia following reports of users developing agranulocytosis, occasionally resulting in death. The safety of the drug is still controversial, resulting in varying levels of restriction and regulation worldwide. Dipyrone is still available, however, by prescription and OTC in many countries in Europe, South America, and Asia.