Capecitabine

Capecitabine is indicated for the treatment of several solid tumors, typically as part of combination chemotherapy regimens in adult patients.

• Colorectal cancer, often in metastatic or adjuvant settings.
• Breast cancer, especially HER2‑negative disease.
• Gastric (stomach) cancer, including advanced stages.
• Combination with oxaliplatin (CAPOX) for colorectal cancer.
• Use in clinical trials for other gastrointestinal malignancies.
• Pancreatic cancer in selected patients.
• Anal canal carcinoma as part of multimodal therapy.

Capecitabine may cause a range of adverse effects, varying from mild to severe, that are related to its impact on rapidly dividing cells.

Common

• Nausea and vomiting, often mild to moderate in intensity.
• Diarrhea or loose stools, which may be intermittent.
• Hand‑foot syndrome (palmar‑plantar erythrodysesthesia) causing redness, swelling, or tingling of the palms and soles.
• Fatigue or generalized weakness affecting daily activities.
• Decreased appetite leading to weight loss.

Serious

• Severe neutropenia or leukopenia, increasing infection risk.
• Thrombocytopenia (low platelet count) that may cause easy bruising or bleeding.
• Severe or persistent diarrhea that can lead to dehydration and electrolyte imbalance.
• Cardiotoxicity, including chest pain, shortness of breath, or arrhythmia.
• Severe allergic reactions such as widespread rash, Stevens‑Johnson syndrome, or anaphylaxis.

Before initiating capecitabine therapy, several precautions and warnings should be considered to ensure patient safety and optimal treatment outcomes.

• Assess renal and hepatic function, as impairment can increase drug exposure.
• Monitor complete blood counts regularly to detect neutropenia or thrombocytopenia.
• Evaluate for pre‑existing cardiac disease, given the risk of cardiotoxicity.
• Counsel patients on recognizing early signs of hand‑foot syndrome.
• Avoid use during pregnancy; discuss contraception with women of childbearing potential.
• Adjust dose in elderly patients or those with poor performance status.

Capecitabine may interact with other medicines, affecting its efficacy or increasing toxicity; known interactions are grouped below.

Avoid

• Strong CYP2C9 inhibitors (e.g., fluconazole) that can raise capecitabine levels.
• Anticoagulants such as warfarin, which may have enhanced anticoagulant effect.

Use with caution

• Antiemetics containing dexamethasone, which may alter metabolism.
• Other fluoropyrimidines or 5‑FU–based regimens, increasing risk of overlapping toxicity.
• Drugs causing myelosuppression (e.g., carboplatin) that may exacerbate blood‑cell suppression.
• Herbal supplements like St. John’s wort that induce hepatic enzymes.