When Iron Bites Back: Severe Thrombocytopenia After Intravenous Iron Sucrose Therapy (Venofer)

Iron deficiency anemia (IDA) commonly presents with normal or elevated platelet counts, while thrombocytopenia is rare. Intravenous iron sucrose (Venofer) is widely used and generally well tolerated. We report the case of a 71-year-old female with chronic IDA who developed severe thrombocytopenia following iron sucrose therapy. Baseline hemoglobin was 6.3 g/dL with a platelet count of 229 × 10³/µL. After two doses of intravenous iron, hemoglobin improved to 9.3 g/dL, but platelets rapidly declined to 11 × 10³/µL. Extensive workup excluded thrombotic microangiopathy, autoimmune disease, infection, and malignancy, and peripheral smear showed no schistocytes. Iron therapy was discontinued, and supportive treatment, including platelet transfusions, led to gradual recovery. Naranjo scoring suggested a probable drug-induced reaction. This case highlights a rare but important adverse effect of intravenous iron therapy and underscores the need for close hematologic monitoring.