Capecitabine is a prodrug to be activated preferentially at tumor sites, thus improving the therapeutic efficacy of 5-fluorouracil
(5-FU). This drug is converted to 5-FU in a three-step process. First, it is metabolized to 5 -deoxy-5-fluorocyti-dine (5 DFCR) by a liver enzyme. Second, 5 DFCR is converted into 5 -deoxy-5-fluoridine by the enzyme cytidine deaminase. This conversion occurs in hepatic and tumor tissues.

Patients with metastatic breast cancer refractory to paclitaxel and an anthracycline-containing regimen, or cancer resistant to paclitaxel and for whom further anthracycline therapy is not indicated.

Capecitabine is metabolized in the liver and at the cellular level, and is excreted from the lungs and in the urine. Half-life: 45 minutes.

♦ Adult: 2500 mg/m2 daily PO in two divided doses about 12 hours apart given at the end of a meal for 2 weeks followed by a one-week rest period. Given in a three-week cycle.