Treatment of radiation or cyclophosphamide induced hemorrhagic cystitis using conjugated estrogen.

Five patients with severe hemorrhagic cystitis induced by radiation and/or cyclophosphamide were systematically treated with conjugated estrogen. Two patients received conjugated estrogen twice each day (1 mg. per kg.) intravenously, followed on day 3 and thereafter by 5 mg. per day orally. Hematuria decreased markedly 6 to 8 hours after the initial dose and urine color became light yellow within 1 to 3 days. The other 3 patients received 5 mg. conjugated estrogen per day orally and urine color became clear within 4 to 7 days. Hematuria did not recur during 12 to 22 months in 4 patients who received daily conjugated estrogen (1.25 mg.). However, transient episodes of mild hematuria persisted in 1 patient during the 3-month followup despite a higher dose of conjugated estrogen (10 mg. per day). Complications, including thromboembolism and other side effects associated with conjugated estrogen, were not observed in these patients. We postulate that conjugated estrogen controls hematuria in hemorrhagic cystitis by decreasing the fragility of the mucosal microvasculature of the bladder.