- Peptic ulcer disease, active bleeding diathesis, lower gastrointestinal bleeding, platelet or other hematologic abnormality currently active or clinically active in the past year, hematuria, positive stool guaiac, prolonged PT or PTT, BUN > 40mg%, serum creatinine > 2.0mg%, thrombocytopenia or neutropenia as defined by the lower limit of normal for the platelet count or white blood cell count, respectively (absolute neutrophil count of > 1800/mm3 required for participation), or > 2 times the upper range of normal on liver function tests (SGOT, SGPT, total bilirubin)