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.