Cyclophosphamide, sold under the trade names Neosar and Cytoxan, is one of a class of drugs known as alkylating agents. It is used as chemotherapy to treat cancer and autoimmune diseases like rheumatoid arthritis, birdshot retinochoroidopathy and Wegener's granulomatosis.
Against cancer, cyclophosphamide is often combined with doxorubicin, vincristine or bleomycin. It is one of the older, but more effective, antineoplastics.
Like many anti-cancer agents, this drug is associated with severe side effects. It causes nausea and vomiting in 50-80% of those receiving it. It can also cause bladder damage, hair loss, diarrhea and neutropenia, while increasing the risk for life-threatening infections and secondary cancers.