Xeloda^® (capecitabine), a chemotherapy medication that is available by prescription, is commonly used to treat breast cancer and colorectal cancer. The medication works by interfering with a cell's ability to make new DNA, decreasing the amount of cancer cells that multiply. Xeloda also causes certain parts of the cells to stop functioning. Although most people tolerate the medication well, Xeloda is not suitable for everyone. A few of the conditions you should let your healthcare provider know about before taking the medication include kidney or liver disease, as well as any allergies you may have.