Carmustine is a cancer medication that interferes with the growth and spread of cancer cells in the body. Carmustine is used to treat brain tumors, Hodgkin's disease, multiple myeloma, and non-Hodgkin's lymphoma. Although it is generally agreed that carmustine alkylates DNA and RNA, it is not cross-resistant with other alkylators. As with other nitrosoureas, it may also inhibit several key enzymatic processes by carbamoylation of amino acids in proteins. Pulmonary toxicity characterized by pulmonary infiltrates and/or fibrosis has been reported to occur from 9 days to 43 months after treatment with BiCNU and related nitrosoureas. A frequent and serious toxicity of BiCNU is delayed myelosuppression. Nausea and vomiting after intravenous administration of BiCNU are noted frequently. Greater myelotoxicity (e.g., leukopenia and neutropenia) has been reported when carmustine was combined with cimetidine.