Drug Guide
Tafamidis Meglumine
Classification
Therapeutic: Treatment of transthyretin amyloid cardiomyopathy, transthyretin amyloidosis
Pharmacological: Tafamidis is a selective transthyretin stabilizer
FDA Approved Indications
- Transthyretin amyloid cardiomyopathy (ATTR-CM)
Mechanism of Action
Tafamidis binds to the thyroxine-binding sites of transthyretin, stabilizing the tetramer and preventing dissociation into monomers that form amyloid deposits, thereby reducing amyloid formation and deposition.
Dosage and Administration
Adult: 80 mg once daily, with food
Pediatric: Not approved for pediatric use
Geriatric: No specific dose adjustment required, but caution in elderly patients
Renal Impairment: No dose adjustment needed for mild to moderate impairment; limited data in severe impairment
Hepatic Impairment: No dose adjustment specified
Pharmacokinetics
Absorption: Rapidly absorbed with peak plasma levels in approximately 1 hour
Distribution: Extensively bound to plasma proteins (~99%)
Metabolism: Primarily metabolized via glucuronidation; limited CYP involvement
Excretion: Excreted mainly in feces; minimal unchanged drug in urine
Half Life: Approximately 49 hours
Contraindications
- Hypersensitivity to tafamidis or any component of the formulation
Precautions
- Use with caution in hepatic impairment; monitor for adverse effects; pregnancy category C, risk cannot be ruled out; breast-feeding: no data available, consider risks
Adverse Reactions - Common
- Increased liver enzymes (ALT, AST) (Less common)
- Hypersensitivity reactions (Uncommon)
Adverse Reactions - Serious
- Progressive multifocal leukoencephalopathy (very rare) (Rare)
- Heart failure exacerbation (Rare)
Drug-Drug Interactions
- No significant interactions reported
Drug-Food Interactions
- No specific interactions
Drug-Herb Interactions
- Limited data, caution advised
Nursing Implications
Assessment: Baseline liver function tests, cardiac function monitoring as appropriate
Diagnoses:
- Risk for hepatic injury
- Ineffective tissue perfusion related to amyloid cardiomyopathy
Implementation: Administer with food, monitor for side effects, educate patient about adherence and side effects
Evaluation: Assess symptom progression, monitor liver enzymes, evaluate for adverse reactions
Patient/Family Teaching
- Take medication exactly as prescribed, with food
- Report any signs of liver problems (jaundice, dark urine), allergic reactions, or unusual symptoms
- Maintain regular follow-up appointments for monitoring
Special Considerations
Black Box Warnings:
- No black box warnings currently
Genetic Factors: Genetic testing for transthyretin mutations may inform treatment
Lab Test Interference: Potential for elevated liver enzymes; monitor accordingly
Overdose Management
Signs/Symptoms: No specific overdose data, but watch for hypersensitivity or hepatic toxicity
Treatment: Supportive care; consider activated charcoal if ingestion recent; consult poison control
Storage and Handling
Storage: Store at room temperature between 20°C and 25°C (68°F to 77°F)
Stability: Stable at room temperature for up to 24 months