Novalgetol

Metamizole or dipyrone, is a painkiller, spasm reliever and fever reliever. Like ibuprofen, it has anti-inflammatory effects. It is most commonly given by mouth or by injection. Metamizole or dipyrone, is a painkiller, spasm reliever and fever reliever. Like ibuprofen, it has anti-inflammatory effects. It is most commonly given by mouth or by injection. Although it is still available over-the-counter in some countries, it is prescription or banned in other countries, due to its potential for adverse events, including agranulocytosis. It is in the ampyrone sulfonate family of medicines. It was patented in 1922. It was first used medically in Germany under the brandname 'Novalgin' and for many years it was available over-the-counter in most countries, until its toxicities became apparent. Metamizole is marketed under various trade names. It is primarily used for perioperative pain, acute injury, colic, cancer pain, other acute/chronic forms of pain and high fever unresponsive to other agents. 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. Metamizole has a potential of blood-related toxicity (blood dyscrasias), but causes less kidney, cardiovascular, and gastrointestinal toxicity than non-steroidal anti-inflammatory drugs (NSAIDs). Like NSAIDs, it can trigger bronchospasm or anaphylaxis, especially in those with asthma. Serious side effects include agranulocytosis, aplastic anaemia, hypersensitivity reactions (like anaphylaxis and bronchospasm), toxic epidermal necrolysis and it may provoke acute attacks of porphyria, as it is chemically related to the sulfonamides. The relative risk for agranulocytosis appears to greatly vary according to the country of estimates on said rate and opinion on the risk is strongly divided. Genetics may play a significant role in metamizole sensitivity. It is suggested that some populations are more prone to suffer from metamizole induced agranulocytosis than others. As an example, metamizole-related agranulocytosis seems to be an adverse effect more frequent in British population as opposed to Spaniards. Previous hypersensitivity (such as agranulocytosis or anaphylaxis) to metamizole or any of the excipients (e.g. lactose) in the preparation used, acute porphyria, impaired haematopoiesis (such as due to treatment with chemotherapy agents), third trimester of pregnancy (potential for adverse effects in the newborn), lactation, children with a body weight below 16 kg, history of aspirin-induced asthma and other hypersensitivity reactions to analgesics. Oral anticoagulants (blood thinners), lithium, captopril, triamterene and antihypertensives may also interact with metamizole, as other pyrazolones are known to interact adversely with these substances.