Late hemorrhagic cystitis following low-dose cyclophosphamide therapy.

Hemorrhagic cystitis is a recognized acute complication of cyclophosphamide (Cytoxan) therapy in the treatment of malignant disease. More recently, lower dose, long-term cyclophosphamide therapy has been used in the treatment of autoimmune diseases including rheumatoid arthritis. In 3 patients hemorrhagic cystitis developed after long-term cyclophosphamide therapy for rheumatoid arthritis. Even in low dosage, this drug may cause hemorrhagic cystitis.