Chemotherapy drugs work in different ways to damage cancer cells and stop their growth and replication. Some key classes of chemotherapy drugs include alkylating agents which damage DNA, antimetabolites which interfere with cell metabolism, anthracyclines which attack enzymes in DNA, mitotic inhibitors which stop cell replication, and topoisomerase inhibitors which also attack cell division enzymes. Steroids are also used to reduce side effects of chemotherapy like nausea and vomiting. While chemotherapy targets fast-growing cancer cells, it can also damage healthy cells and cause side effects.