Adecuación de la seguridad del metamizol y agranulocitosis

OBJECTIVE: To analyze whether the drug safety update issued by the Spanish Agency of Medicines and Healthcare Products (AEMPS), dated October 30, 2018, on agranulocytosis and metamizole contains accurate and necessary information to protect patients from the presentation of this adverse reaction (AR) and if the official documentation of medicines containing metamizole for doctors, pharmacists and the general population conforms to the guidelines of the AEMPS to reduce this risk. SETTING AND PARTICIPANTS: Drug safety update, bibliographic search, information at the European Medicines Agency on metamizole drugs marketed in Spain, technical datasheets, leaflets, Bot PLUS Health Information Database and Catalog of Pharmaceutical Specialties. Notification of 4 cases of agranulocytosis due to metamizole after the drug safety update was issued. MAIN INTERVENTIONS AND MEASUREMENTS: Comparison of the key points of the drug safety update and official documents on metamizole with the bibliography. Description of the 4 cases of agranulocytosis due to metamizole and application of the causality and severity algorithm. RESULTS: The drug safety update contains omissions and contradiction in respect to the bibliography and the actual use of metamizole in healthcare practice. The official documents show a lack of updating, unapproved indications and doses higher than those recommended. The drug safety update has not stopped the presentation of cases of agranulocytosis due to metamizole. CONCLUSIONS: The AEMPS drug safety update can be improved and it is necessary to update the official information documents on metamizole for health professionals and patients in order to decrease the risk of agranulocytosis.