Thrombotic thrombocytopenic purpura following zoledronic acid infusion with a fatal outcome.

A 56-year-old woman presented with generalised bone pain with bone mineral density showing severe osteoporosis for which she received a single 4 mg infusion of zoledronic acid (ZA). On the second day following the infusion, she developed fever with altered sensorium. A complete blood count showed anaemia and thrombocytopenia with peripheral blood smear repeatedly showing schistocytes, anisopoikilocytes and target cells. Serum biochemistry revealed elevation of serum creatinine at 1.5 mg/dl. In view of microangiopathic haemolytic anaemia, fever, renal insufficiency, neurological abnormality and thrombocytopenia, the patient was presumed to have developed thrombotic thrombocytopenic purpura (TTP). Accordingly, a combination therapy with glucocorticoids and fresh frozen plasma transfusion was begun pending plasmapharesis. She manifested a fluctuating level of mental status with progressive purpuric and ecchymotic lesions and she sustained cardiorespiratory arrest from which she could not be revived. The temporal sequence of events following ZA infusion with typical manifestations of TTP strongly suggests ZA as the most probable cause of her fatal TTP.