Metamizole-induced agranulocytose- a rare but potentially fatal side effect

Introduction In 2019, metamizole was the second most commonly prescribed drug in Germany despite the known risk of agranulocytosis and despite the strict indication.

Case report We report about a female patient who presented with fever and sore throat for 7 days. The examination revealed acute tonsillitis and cervical lymphadenopathy. Laboratory diagnostics showed a leucopenia of 1.01 * 103/µl (granulocytes below 1%). CRP was 30.68 mg/dl and IL-6 was 237.8 pg/ml. In the medical history, the patient reported that she had taken metamizole 7 days ago. In addition, she reported about pain in the left thigh. An inspection of the thigh revealed an extensive phlegmon. High-dose i.v. antibiotic therapy with piperacillin/tazobactam and clindamycin was given and a visceral surgery consultation was performed. When necrotising fasciitis was diagnosed in the thigh area, an emergency surgical intervention was performed with VAC therapy and split skin graft covering in the course. The patient was isolated in our intensive care unit. G-CSF 34 million units were administered s.c. once daily. After 3 days, the administration of G-CSF could be stopped. The patient stayes a total of 29 days in hospital.

Conclusion Agranulocytosis is a dangerous side effect of taking metamizole. Since many of the unspecific symptoms of agranulocytosis occur in the ENT area, this side effect should always be considered by the ENT physician. In general, a strict indication, the exhaustion of alternative analgesics and regular blood count checks are recommended.

Conflict of Interest

The author declares that there is no conflict of interest.

Publication History

Article published online:
24 May 2022