Chemotherapy — Hemorrhagic Cystitis & Mucositis

Cyclophosphamide is an alkylating agent used in cancer treatment and severe autoimmune conditions. Its liver metabolism produces acrolein, a toxic byproduct that accumulates in urine and directly damages the bladder mucosa, causing hemorrhagic cystitis — presenting as dysuria, urinary frequency, and frank hematuria that can become life-threatening. The key nursing intervention is aggressive hydration (typically 3 L/day or IV fluids) to dilute acrolein and promote frequent voiding. Mesna (sodium 2-mercaptoethane sulfonate) is the specific uroprotectant: it binds acrolein in the bladder, neutralizing it before damage occurs. Mesna is given IV or orally, timed with cyclophosphamide doses. Patients must void every 1–2 hours during and after infusion — holding urine concentrates acrolein. Mucositis is the other hallmark adverse effect across many chemotherapy agents but is prominent with cyclophosphamide and methotrexate. Rapidly dividing mucosal cells in the mouth and GI tract are destroyed, causing painful oral ulceration, difficulty swallowing, and infection risk. Nursing care includes oral assessments using a standardized tool before each cycle, soft-bristle toothbrushes, bland rinses (normal saline or sodium bicarbonate — never alcohol-based mouthwash), and cryotherapy (ice chips during short infusions to vasoconstrict oral mucosa and reduce drug delivery to those tissues).