Background: Despite the controversial international debate on the use of metamizole as a standard analgesic, the prescription figures for Germany have increased constantly during recent years. However, metamizole can lead to the rare and severe medical condition called agranulocytosis.
Materials and methods: Between January 2009 and January 2014, 5 patients with metamizole-induced agranulocytosis presented themselves at the Interdisciplinary Emergency Center of the University Clinic Bonn. According to their leading ENT symptoms, they were transferred to the otorhinolaryngological department. We retrospectively evaluated metamizole medication, all general patient data and previous diseases, as well as disease course and the respective therapies.
Results: Within the scope of the different treatments--surgery after trauma (n=2), elective orthopedic surgery (n=2), tonsillitis treatment (n=1)--the patients (n=5; mean age 30 years) had made regular ambulant use of metamizole for several days or weeks (4-28 days, mean 16.8 days). Daily oral dose ranged from 625 to 2000 mg/d (mean 1500 mg/d). Subsequently, patients required treatment for clinical symptoms of agranulocytosis (e.g. tonsillitis with severe odynophagia and significantly reduced general condition). All patients were monitored in an intermediate or intensive care unit (3-14 days, mean 10 days). No patients died.
Discussion: As our cases show, when using metamizole as a standard analgesic, the treating otolaryngologist should look for clinical symptoms of agranulocytosis and inform patients about possible adverse effects. We recommend strict indication setting, regular blood analyses during long-term medication and consideration of alternative analgesics (e.g. NSAR).