- Class: Antimetabolite – fluoropyrimidine prodrug.
- Type: Oral cytotoxic chemotherapy.
Mechanism of Action (MOA)
- Oral prodrug of 5-fluorouracil (5-FU).
- Converted in the liver and tumor tissues to 5-FU → inhibits thymidylate synthase.
- Disrupts DNA synthesis and RNA function → apoptosis.
- Preferential activation in tumor tissue due to higher thymidine phosphorylase.
Clinical Uses
- Metastatic colorectal cancer – monotherapy or combination with oxaliplatin (CAPOX) or irinotecan (CAPIRI).
- Breast cancer – metastatic or adjuvant therapy in combination regimens.
- Gastrointestinal cancers – off-label uses in some gastric, pancreatic tumors.
Dosing (Adults)
- Colorectal cancer (monotherapy): 1250 mg/m² orally twice daily for 14 days, followed by 7-day rest (21-day cycle).
- Dose adjustments required for:
- Renal impairment (CrCl <50 mL/min)
- Hepatic impairment
- Toxicity management (hand-foot syndrome, diarrhea, myelosuppression)
Toxicities
- Gastrointestinal: diarrhea, nausea, vomiting, mucositis.
- Dermatologic: hand-foot syndrome (palmar-plantar erythrodysesthesia).
- Hematologic: anemia, neutropenia, thrombocytopenia (less severe than IV 5-FU).
- Fatigue, weakness.
- Rare: cardiotoxicity (angina, ischemia), hyperbilirubinemia.
Monitoring
- CBC before each cycle.
- Renal function (CrCl, BUN, creatinine).
- Liver function tests.
- Monitor for hand-foot syndrome, diarrhea, and mucositis.
- Dose adjustments for toxicity (especially grade ≥2 adverse effects).
Summary
Capecitabine (Xeloda®) is an oral 5-FU prodrug used mainly in colorectal and breast cancer. Key concerns are GI toxicity, hand-foot syndrome, myelosuppression, and renal/hepatic dosing adjustments, requiring regular CBC, renal/liver monitoring, and patient education on skin care and hydration.