Capecitabine

Capecitabine is an oral tablet formulation containing the active ingredient capecitabine, an antimetabolite fluoropyrimidine used as a prescription (Rx) medication in the European Union. It is a prodrug that is converted to 5‑fluorouracil in tumor tissue, where it interferes with DNA and RNA synthesis, helping to control the growth of certain cancers. The product is supplied without a specific brand name and is administered under medical supervision.

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.