Capecitabineinteractions

Allopurinol: Avoid concomitant use of allopurinol with capecitabine tablets.

Leucovorin: Closely monitor for toxicities when capecitabine tablets is coadministered with leucovorin.

CYP2C9 substrates: Closely monitor for adverse reactions when CYP2C9 substrates are coadministered with capecitabine tablets.

Vitamin K antagonists: Monitor INR more frequently and dose adjust oral vitamin K antagonist as appropriate

Phenytoin: Closely monitor phenytoin levels in patients taking capecitabine tablets concomitantly with phenytoin and adjust the phenytoin dose as appropriate.

Nephrotoxic drugs: Closely monitor for signs of renal toxicity when capecitabine tablets is used concomitantly with nephrotoxic drugs.

7.1 Effect of

Other Drugs on Capecitabine Tablets Allopurinol Concomitant use with allopurinol may decrease concentration of capecitabine’s active metabolites, which may decrease efficacy. Avoid concomitant use of allopurinol with capecitabine tablets. Leucovorin The concentration of fluorouracil is increased and its toxicity may be enhanced by leucovorin, folic acid, or folate analog products. Deaths from severe enterocolitis, diarrhea, and dehydration have been reported in elderly patients receiving weekly leucovorin and fluorouracil. Instruct patients not to take products containing folic acid or folate analog products unless directed to do so by their healthcare provider.

7.2 Effect of

Capecitabine Tablets on Other Drugs CYP2C9 Substrates Capecitabine tablets increased exposure of CYP2C9 substrates, which may increase the risk of adverse reactions related to these substrates. Closely monitor for adverse reactions of CYP2C9 substrates where minimal concentration changes may lead to serious adverse reactions when used concomitantly with capecitabine tablets (e.g., anticoagulants, antidiabetic drugs). Vitamin K Antagonists Capecitabine tablets increases exposure of vitamin K antagonist, which may alter coagulation parameters and/or bleeding and could result in death. These events may occur within days of treatment initiation and up to 1 month after discontinuation of capecitabine tablets. Monitor INR more frequently and refer to the prescribing information of oral vitamin K antagonist for dosage adjustment, as appropriate, when capecitabine tablets is used concomitantly with vitamin K antagonist. Phenytoin Capecitabine tablets may increases exposure of phenytoin, which may increase the risk of adverse reactions related to phenytoin. Closely monitor phenytoin levels and refer to the prescribing information of phenytoin for dosage adjustment, as appropriate, when capecitabine tablets is used concomitantly with phenytoin.

7.3 Nephrotoxic

Drugs Due of the additive pharmacologic effect, concomitant use of capecitabine tablets with other drugs known to cause renal toxicity may increase the risk of renal toxicity. Closely monitor for signs of renal toxicity when capecitabine tablets is used concomitantly with nephrotoxic drugs (e.g. platinum salts, irinotecan, methotrexate, intravenous bisphosphonates).