Metamizole and the possible risks for those taking fever and pain medications that contain it. AIFA warns with seven fundamental indications

The risks associated withtaking metamizole have been highlighted again byItalian Medicines Agency (Aifa), which with an information note agreed with the European regulatory authorities, and released on 9 December, once again placed emphasis on the serious outcomes of agranulocytosisa known side effect of the active ingredient belonging to the class of NSAIDs, non-steroidal anti-inflammatory drugs.

Agranulocytosis, what it is and how it manifests itself

Agranulocytosis is an acute pathological condition of the blood, characterized by a severe decrease in the number of circulating granulocytes and one resulting in increased susceptibility to infections. Common symptoms can be fever, asthenia and candidiasis. Agranulocytosis can be caused by congenital alterations of medullary myelopoiesisbut it can also be caused by specific drugssuch as anticancer chemotherapeutics, antipsychotics, some non-steroidal anti-inflammatory drugs and other drugs with a sulphonamide structure.

«Agranulocytosis is a very rare known side effect (<1/10,000) of metamizole, which in some cases can have a fatal outcome", we read on the website of the Swiss Institute for Therapeutic Products SwissMedic. “THE Typical signs are inflammatory lesions of the mucosa (oropharyngeal, anorectal, genital), pharyngeal pain And fever. In patients on antibiotic therapy, the typical signs may also be minimal. Agranulocytosis caused by metamizole is an allergic immune reaction which lasts at least a week. This reaction is not at all related to the dose administered and can occur at any time during treatment.”

7 key information according to AIFA

With its note, AIFA reiterated that patients treated in particular with medicinal products containing metamizole should be informed accordingly:

1.to the early symptoms suggestive of agranulocytosisincluding fever, chills, sore throat, and painful sores of the mucous membranes, especially in the mouth, nose, and throat or in the genital or anal regions;

2.to the need to maintain high attention on these symptoms, since they can occur at any time during treatment, even shortly afterwards interruption of treatment;

3.to the need to stop treatment and seek medical attention immediately if they develop these symptoms.

4.If metamizole is taken for feversome symptoms of an emerging agranulocytosis may go unnoticed. Furthermore, symptoms may be masked in patients being treated with antibiotic therapy.

5.If agranulocytosis is suspecteda complete blood count (including white blood cell count) should be performed immediately and treatment discontinued pending the results. If agranulocytosis is confirmed, treatment should not be reintroduced.

6.The routine blood count monitoring it is not recommended in patients treated with medicinal products containing metamizole.

7.The metamizole is contraindicated in patients with a history of agranulocytosis induced by metamizole (or other pyrazolones or pyrazolidines), with impairment of bone marrow function or with diseases of the hematopoietic system.