What is capecitabine and what is a characteristic toxicity?

• A. Capecitabine is an oral prodrug of 5-FU; hand-foot syndrome is a common toxicity.
• B. Capecitabine is a monoclonal antibody; infusion reactions.
• C. Capecitabine is a platinum-based compound; nephrotoxicity.
• D. Capecitabine is a radioisotope; causes radiation dermatitis.

Answer: (A)

Capecitabine is an oral prodrug that is converted to the chemotherapy agent 5-fluorouracil in the body, with activation favored in tumor tissue due to higher levels of the activating enzyme thymidine phosphorylase. A characteristic toxicity of this drug is hand-foot syndrome (palmar-plantar erythrodysesthesia), which presents as redness, swelling, tenderness, and sometimes peeling of the skin on the palms and soles and can limit dosing. This toxicity is particularly associated with fluoropyrimidines like capecitabine and helps distinguish it from drugs in other classes. Capecitabine is not a monoclonal antibody and doesn’t typically cause infusion reactions; it is not platinum-based and isn’t mainly nephrotoxic; and it is not a radioisotope and does not cause radiation dermatitis.