Generic Name

Capecitabine

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Classification

FDA Approved Indications

• Adjuvant treatment of breast cancer
• Metastatic colorectal cancer
• Metastatic breast cancer

Mechanism of Action

Capecitabine is a prodrug that is enzymatically converted into 5-fluorouracil (5-FU) within the body. 5-FU inhibits thymidylate synthase, disrupting DNA synthesis and leading to apoptotic cell death in rapidly dividing cancer cells.

Dosage and Administration

Adult: Typically 1250 mg/m² twice daily for 14 days followed by 7 days off; specific dosing varies based on indication and patient factors.

Pediatric: Not approved for pediatric use; dosing not established.

Geriatric: Use with caution; consider renal and hepatic function.

Renal Impairment: Adjust dose based on severity of impairment; generally, dose reduction is recommended in moderate to severe impairment.

Hepatic Impairment: Use with caution; monitor closely as metabolism may be affected.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed in body tissues.

Metabolism: Converted enzymatically to 5-FU mainly in tumor tissue; undergoes hepatic metabolism.

Excretion: Primarily renal excretion of metabolites.

Half Life: T1/2 of capecitabine approximately 0.75 hours; active metabolite 5-FU has a half-life of approximately 10-20 minutes.

Contraindications

• Hypersensitivity to capecitabine or fluoropyrimidines.
• History of severe pulmonary, cerebellar, or cardiotoxic reactions.

Precautions

• Monitor for signs of myelosuppression, hand-foot syndrome, diarrhea, and cardiotoxicity.
• Use with caution in renal or hepatic impairment.
• Pregnancy Category D: risk to fetus; avoid in pregnancy.

Adverse Reactions - Common

• Hand-Foot Syndrome (palmar-plantar erythrodysesthesia) (Common)
• Diarrhea (Common)
• Nausea and vomiting (Common)
• Mucositis/stomatitis (Common)
• Myelosuppression (neutropenia, anemia, thrombocytopenia) (Common)

Adverse Reactions - Serious

• Severe neutropenia and risk of infections (Serious)
• Thromboembolic events (Serious)
• Cardiotoxicity (angina, myocardial infarction) (Serious)
• Severe diarrhea leading to dehydration (Serious)
• Hand-foot syndrome leading to dose modification or discontinuation (Serious)

Drug-Drug Interactions

• Warfarin (may increase bleeding)
• Other myelosuppressive agents
• Virustatic agents

Drug-Food Interactions

• May influence absorption if taken with certain foods; generally administered without regard to food.

Drug-Herb Interactions

N/A

Nursing Implications

Patient/Family Teaching

• Advise patient to report symptoms such as severe diarrhea, hand-foot syndrome, or signs of infection immediately.
• Use sun protection, as skin may become more sensitive.
• Maintain hydration and nutritional intake.
• Avoid pregnancy; use effective contraception during and for at least 6 months after treatment.

Special Considerations

Black Box Warnings:

• Capecitabine can cause severe and sometimes fatal diarrhea, neutropenia, and hand-foot syndrome.
• Use with caution in patients with dihydropyrimidine dehydrogenase (DPD) deficiency.
• Cardiotoxicity risk may be increased in patients with underlying cardiac disease.

Genetic Factors: DPD deficiency can cause increased toxicity; testing may be considered.

Lab Test Interference: May cause false elevation of INR tests in patients on warfarin.

Overdose Management

Signs/Symptoms: Severe diarrhea, neutropenia, mucositis, neurotoxicity, or cardiotoxicity.

Treatment: Supportive care including hydration, blood transfusions, antibiotics for infection, and symptomatic management; no specific antidote.

Storage and Handling

Storage: Store at room temperature, 20°C to 25°C (68°F to 77°F).

Stability: Stable when stored properly; discard if expired or damaged.