mitomycin /mītəmī″sin/ , an antineoplastic antibiotic. INDICATIONS: It is prescribed in the treatment of malignant neoplastic diseases, including disseminated adenocarcinoma of the stomach and pancreas, bladder cancer, and colon cancer. CONTRAINDICATIONS: Clotting deficiency, thrombocytopenia, or known hypersensitivity to this drug prohibits its use. ADVERSE EFFECTS: The most serious adverse effect is bone marrow depression. GI disturbances, alopecia, and skin reactions commonly occur.