Generic Name

Bexarotene

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Classification

FDA Approved Indications

• Cutaneous T-cell lymphoma (CTCL) refractory to at least one prior systemic therapy

Mechanism of Action

Bexarotene selectively activates retinoid X receptors, leading to modulation of gene expression involved in cell differentiation and apoptosis, which helps control malignant T-cell proliferation in CTCL.

Dosage and Administration

Adult: Starting dose typically 300 mg/m²/day orally, adjusted based on response and tolerance.

Pediatric: Not approved for pediatric use; safety and efficacy not established.

Geriatric: Use with caution, considering potential increased sensitivity and comorbidities.

Renal Impairment: No specific dosage adjustment recommended; monitor closely.

Hepatic Impairment: Use with caution; hepatic function should be monitored, dose adjustments may be necessary.

Pharmacokinetics

Absorption: Well absorbed orally, with peak plasma concentrations within 2 hours.

Distribution: Highly plasma protein bound (~99%).

Metabolism: Primarily metabolized by the liver via CYP3A4 enzymes.

Excretion: Metabolites excreted mainly in the feces, minor renal excretion.

Half Life: Approximately 7 hours, but can be longer due to tissue binding.

Contraindications

• Hypersensitivity to bexarotene or other retinoids.

Precautions

• Risk of hyperlipidemia, hypothyroidism, pancreatitis, hepatotoxicity; requires regular monitoring.
• Use with caution in pregnancy; teratogenic risk.

Adverse Reactions - Common

• Hyperlipidemia (Very common)
• Hypothyroidism (Common)
• CNS effects (headache, fatigue) (Common)

Adverse Reactions - Serious

• Pancreatitis (Rare)
• Hepatotoxicity (Rare)
• Teratogenicity (category X) (N/A, contraindicated in pregnancy)

Drug-Drug Interactions

• CYP3A4 inhibitors (e.g., ketoconazole, erythromycin) may increase bexarotene levels.
• CYP3A4 inducers (e.g., rifampin) may decrease effectiveness.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Patient/Family Teaching

• Take medication with a meal containing fat to improve absorption.
• Report symptoms of hyperlipidemia, hypothyroidism, or pancreatitis.
• Use effective contraception during therapy and for at least 1 month after discontinuation.

Special Considerations

Black Box Warnings:

• Pregnancy Category X: contraindicated in pregnant women due to high teratogenic risk.

Genetic Factors: None specifically identified.

Lab Test Interference: May cause hyperlipidemia and hypothyroidism, requiring routine labs.

Overdose Management

Signs/Symptoms: Severe hyperlipidemia, hepatotoxicity, hypothyroidism.

Treatment: Discontinue drug; provide supportive care; manage symptoms accordingly.

Storage and Handling

Storage: Store at room temperature away from light and moisture.

Stability: Stable under recommended storage conditions.