Case Report of Temozolamide Associated Steroid-Refractory ITP and Successful Treatment with Rituximab.

We report the first case of temozolamide associated ITP and successful treatment with Rituximab. A 59 year-old male with grade III anaplastic astrocytoma is treated with resection followed by adjuvant temozolamide and gamma knife radiation therapy (XRT). He had been taking ramipril for hypertension, and atorvastatin for hyperlipidemia for greater than 1 year. He began taking phenytoin for seizure prophylaxis at the time of his original diagnosis in December of 2004. His CBC is normal at baseline. He recieves XRT from 2/1/05 until 2/15/05 with a normal platelet count of 142 on 4/21/05. He restarts temozolamide from 4/22 to 4/26 and presents with petechiae and platelet count 0. He receives platelet transfusion but platelet count remians at 3. A bone marrow biopsy confirms adequate megakaryoctes. He develops subcutaneous hemorrhage in the neck and is hospitalized for airway precautions. Prednisone at 2mg/kg and IVIG are given with no response. Rituximab is given weekly x 4 weeks at 375 mg/m2 with response by day 22 to platelet count of 123. The response is durable. See table 1.