Drug Guide
Floxuridine
Classification
Therapeutic: Antineoplastic agent
Pharmacological: Antimetabolite (Thymidylate synthase inhibitor)
FDA Approved Indications
- Adjunctive therapy for gastrointestinal carcinomas (primarily colorectal cancer)
Mechanism of Action
Floxuridine is a pyrimidine analog of deoxyribonucleoside that inhibits DNA synthesis by interfering with thymidylate synthase, leading to subsequent inhibition of DNA replication and cell proliferation.
Dosage and Administration
Adult: Typically, 370-550 mcg/m2 administered intra-arterially or intravenously daily for 5 consecutive days, repeated every 4 weeks, as per treatment protocol.
Pediatric: Data is limited; use is generally off-label and based on specific clinical protocols, with careful dosing adjustments.
Geriatric: No specific dosage adjustment required, but caution and close monitoring are advised due to possible decreased renal or hepatic function.
Renal Impairment: Dose adjustment may be necessary; consult specific protocols.
Hepatic Impairment: Use cautiously; no specific adjustments established.
Pharmacokinetics
Absorption: Variable, depends on administration route; intra-arterial infusion provides high local concentrations.
Distribution: Widely distributed, including crossing the blood-brain barrier in some cases.
Metabolism: Metabolized in the liver to inactive metabolites.
Excretion: Primarily excreted through the kidneys.
Half Life: Approximately 15-30 minutes in plasma.
Contraindications
- Hypersensitivity to floxuridine or other pyrimidine analogs.
Precautions
- Use with caution in patients with hepatic or renal impairment, pregnancy, or lactation. Monitor for hypersensitivity reactions, myelosuppression, and hepatic toxicity.
Adverse Reactions - Common
- Myelosuppression (Common)
- Stomatitis (Common)
- Nausea and vomiting (Common)
- Elevated liver enzymes (Common)
Adverse Reactions - Serious
- Myelodysplastic syndrome or secondary leukemia (Rare)
- Severe hepatotoxicity (Rare)
- Anaphylactic reactions (Rare)
Drug-Drug Interactions
- Other myelosuppressive agents, live vaccines, hepatotoxic drugs.
Drug-Food Interactions
- No significant food interactions reported.
Drug-Herb Interactions
- Limited data; caution with herbal products affecting hepatic or hematologic function.
Nursing Implications
Assessment: Monitor complete blood count (CBC), liver function tests, renal function, and signs of toxicity.
Diagnoses:
- Risk for infection related to myelosuppression.
- Impaired oral mucous membrane related to stomatitis.
Implementation: Administer as prescribed, monitor laboratory values, assess for signs of toxicity, provide supportive care.
Evaluation: Efficacy of tumor response, tolerance to medication, and absence of toxicities.
Patient/Family Teaching
- Report any signs of infection, bleeding, unusual fatigue.
- Maintain good oral hygiene, report mouth sores.
- Follow administration schedule strictly.
- Avoid live vaccines during treatment.
Special Considerations
Black Box Warnings:
- Potential for severe myelosuppression leading to infections or bleeding, which can be life-threatening.
Genetic Factors: Not well established.
Lab Test Interference: May cause elevated liver enzymes or altered blood counts, which can interfere with other diagnostic labs.
Overdose Management
Signs/Symptoms: Severe myelosuppression, hepatotoxicity, gastrointestinal toxicity.
Treatment: Supportive care, including hematopoietic growth factors, transfusions, and symptomatic management; no specific antidote.
Storage and Handling
Storage: Store at controlled room temperature, away from light and moisture.
Stability: Stable under recommended storage conditions until expiration date.