Capecitabine (2 brand names, 1 dosage form, 1 route)
Available dosage forms: TABLET.
Routes of administration: ORAL.
Brand Names
- CAPECITABINE
- XELODA
Boxed Warning
Increased risk of serious adverse reactions or death in patients with complete DPD deficiency Test patients for genetic variants of DPYD prior to initiating capecitabine tablets unless immediate treatment is necessary. Avoid use of capecitabine tablets in patients with certain homozygous or compound heterozygous DPYD variants that result in complete DPD deficiency [see Warnings and Precautions (5.1)]. Increased risk of bleeding with concomitant use of Vitamin K antagonists Altered coagulation parameters and/or bleeding, including death, have been reported in patients taking capecitabine tablets concomitantly with oral vitamin K antagonists, such as warfarin [see Warnings and Precautions (5.2) , Drug Interactions ( 7.2 )] . Clinically significant increases in prothrombin time (PT) and international normalized ratio (INR) have been reported in patients who were on stable doses of a vitamin K antagonist at the time capecitabine tablets was introduced. These events occurred in patients with and without liver metastases. Monitor INR more frequently and adjust the dose of the vitamin K antagonist as appropriate [see Drug Interactions (7.2)].
Contraindications
Capecitabine tablets are contraindicated in patients with history of severe hypersensitivity reaction to fluorouracil or capecitabine [see Adverse Reactions (6.1)].
Adverse Reactions
The following clinically significant adverse reactions are described elsewhere in the labeling: Cardiotoxicity [see Warnings and Precautions (5.3)] Diarrhea [see Warnings and Precautions (5.4)] Dehydration [see Warnings and Precautions (5.5)] Renal Toxicity [see Warnings and Precautions (5.6)] Serious Skin Toxicities [see Warnings and Precautions (5.7)] Palmar-Plantar Erythrodysesthesia Syndrome [see Warnings and Precautions (5.8)] Myelosuppression [see Warnings and Precautions (5.9)] Hyperbilirubinemia [see Warnings and Precautions (5.10)]
Mechanism of Action
Capecitabine is metabolized to fluorouracil in vivo. Both normal and tumor cells metabolize fluorouracil to 5-fluoro-2’-deoxyuridine monophosphate (FdUMP) and 5-fluorouridine triphosphate (FUTP). These metabolites cause cell injury by two different mechanisms. First, FdUMP and the folate cofactor, N5-10-methylenetetrahydrofolate, bind to thymidylate synthase (TS) to form a covalently bound ternary complex. This binding inhibits the formation of thymidylate from 2’-deoxyuridylate. Thymidylate is the necessary precursor of thymidine triphosphate, which is essential for the synthesis of DNA, so that a deficiency of this compound can inhibit cell division. Second, nuclear transcriptional enzymes can mistakenly incorporate FUTP in place of uridine triphosphate (UTP) during the synthesis of RNA. This metabolic error can interfere with RNA processing and protein synthesis.
Overdosage
Administer uridine triacetate within 96 hours for management of capecitabine tablets overdose. Although no clinical experience using dialysis as a treatment for capecitabine tablets overdose has been reported, dialysis may be of benefit in reducing circulating concentrations of 5’-DFUR, a low– molecular-weight metabolite of the parent compound.