Thrombotic thrombocytopenic purpura following metronidazole use: a case report

Background: Drug-induced thrombotic thrombocytopenic purpura (TTP) is an uncommon but serious condition that requires prompt diagnosis and management to prevent severe complications. In TTP, the classic symptoms of fever, microangiopathic hemolytic anemia, thrombocytopenia, and neurological disturbances are intensified, often leading to significant morbidity. Recent evidence suggests that certain medications, including metronidazole, may trigger TTP. Metronidazole is a commonly prescribed antibiotic, and while its association with TTP is rare, it has been documented in the literature. Case report: A 16-year-old female presented to the emergency department after experiencing altered mental status and petechiae on her bilateral shoulders, periorbital, and chest areas. She had taken metronidazole 10 days prior to her presentation. Laboratory results revealed severe thrombocytopenia and other abnormalities consistent with TTP. The diagnosis was confirmed based on both clinical and laboratory findings. Following her diagnosis, she was promptly treated with plasmapheresis, totally receiving 21 units (4,200 ml) of fresh frozen plasma (FFP), along with corticosteroids and dialysis. Conclusion: Although drug-induced TTP is rare, metronidazole should be considered a potential precipitant in patients presenting with TTP. Awareness of such associations is crucial for early diagnosis and management to mitigate the risk of severe outcomes. Further research is needed to better understand the mechanisms by which drugs such as metronidazole may induce TTP and to refine diagnostic criteria for such cases.