Metamizole-induced agranulocytosis from a German intensive care perspective

Background/objectives Metamizole (dipyrone) is a non-opioid analgesic and antipyretic widely used in Germany, with prescriptions having increased more than tenfold since 1997. Despite its popularity, metamizole remains controversial due to the risk of agranulocytosis–a potentially life-threatening adverse reaction that can occur independently of dose or duration of therapy. This study aimed to describe severe cases of metamizole-induced agranulocytosis requiring intensive care treatment and to contextualize them within current consumption data. Methods A retrospective analysis was conducted of all patients admitted to the interdisciplinary medical intensive care units of a tertiary university hospital in southern Germany between April 2022 and April 2025 due to metamizole-associated agranulocytosis. Demographic, clinical, and laboratory data were collected. Bone marrow examinations, microbiological findings, treatment regimens, and outcomes were analyzed descriptively. Results Seven patients required intensive care for metamizole-induced agranulocytosis. All presented with profound neutropenia and severe infections. Two patients died from multiorgan failure despite maximal supportive care. The five survivors experienced prolonged ICU stays (11–60 days) with complications including septic shock, acute respiratory distress syndrome, and renal failure requiring dialysis. None of the patients had pre-existing hematologic disorders or immunosuppression. Conclusion Metamizole-induced agranulocytosis is a rare but potentially severe adverse reaction. Even though its absolute incidence is low relative to the widespread use of metamizole, affected patients may experience life-threatening complications. Awareness of this risk, combined with careful benefit–risk assessment and consideration of alternative analgesics, remains essential for safe and rational use of metamizole in clinical practice.