Metamizole-Induced Agranulocytosis

A 27-year-old female patient presented with a suspected recurrence of her IgA immune complex vasculitis. Following 3-week treatment with prednisolone 15 mg/day and metamizole 2250 mg/day, she developed fever, a sore throat, and wounds at the healed sites of vasculitis. An examination of the patient revealed her significantly reduced general condition, enlarged tonsils with a coating that could be easily removed, and agranulocytosis of 0.01 GpT/l in conjunction with an elevated C-reactive protein level. Besides the superinfected ulcers, other foci of infection were excluded. Bone marrow biopsy revealed an almost complete absence of granulopoiesis. Complete recovery was achieved with antibiotic therapy, isolation, and granulocyte colony stimulating factor (G-CSF) The relative risk of agranulocytosis while taking metamizole is reported to be between 1.5 and 40.2 according to the Drug Commission of the German Medical Association (Arzneimittelkommission der Deutschen Ärzteschaft). While the pathomechanism is unknown, an immunological process is suspected. The reaction is dose-dependent. Metamizole is a prescription-only drug and is not approved in many countries due to its side effects profile. When prescribing the drug, it is the physician’s duty to inform patients about the risk of agranulocytosis and the need to immediately seek medical attention if they experience any suspicious symptoms (fever, sore throat, and inflammation).

Figure

Superinfected ulcers

Dr. med. Diana Kohn, PD Dr. med. Tino Wetzig, Dermatologie, Asklepios Klinik Weißenfels, [e-mail]

Conflict of interest statement: The authors declare that no conflict of interest exists.

Translated from the original German by Christine Rye.

Cite this as: Kohn D, Wetzig T: Metamizole-induced agranulocytosis. Dtsch Arztebl Int 2025; 122: 210b. DOI: 10.3238/arztebl.m2024.0245