Nurses Compass
Drug Guide
Telaprevir
Classification
Therapeutic: Antiviral Agent
Pharmacological: HCV NS3/4A Protease Inhibitor
FDA Approved Indications
- Treatment of chronic hepatitis C virus (HCV) genotype 1 infection in combination with pegylated interferon and ribavirin
Mechanism of Action
Telaprevir inhibits the HCV NS3/4A protease, an enzyme essential for viral replication, thereby preventing the virus from processing its polyprotein and forming mature viral proteins.
Dosage and Administration
Adult: 750 mg every 8 hours with food for 12 weeks in combination therapy.
Pediatric: Not approved for pediatric use.
Geriatric: No specific dose adjustment; use with caution as per general guidelines.
Renal Impairment: No dosage adjustment needed for mild to moderate impairment; limited data for severe impairment.
Hepatic Impairment: Use with caution; no specific dosing recommendations.
Pharmacokinetics
Absorption: Well absorbed; food increases absorption.
Distribution: Wide distribution including plasma.
Metabolism: Primarily metabolized by CYP3A4 and CYP1A2 enzymes.
Excretion: Primarily feces; minimal urinary excretion.
Half Life: 4-5 hours.
Contraindications
- Hypersensitivity to telaprevir or any component.
- Use with drugs highly dependent on CYP3A4 for metabolism and with a narrow therapeutic window.
Precautions
- Use with caution in patients with severe hepatic impairment.
- Monitor for rash, anemia, and gastrointestinal side effects.
- Potential for drug interactions; review all concomitant medications.
Adverse Reactions - Common
- Rash (Common)
- Anemia (Common)
- Discontinuation due to adverse events (Less common)
Adverse Reactions - Serious
- Severe skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis) (Rare)
- Hepatotoxicity (Rare, but serious)
- Anemia leading to atrial fibrillation, heart failure (Rare)
Drug-Drug Interactions
- Strong CYP3A4 inhibitors and inducers (e.g., ketoconazole, rifampin).
- Protease inhibitors and drugs metabolized by CYP3A4.
- HMG-CoA reductase inhibitors (statins).
Drug-Food Interactions
- None specifically noted.
Drug-Herb Interactions
- St. John’s Wort.
Nursing Implications
Assessment: Monitor liver function tests, hemoglobin levels, and signs of rash.
Diagnoses:
- Risk for infection due to immunosuppression.
- Risk for rash and skin integrity issues.
Implementation: Administer with food. Educate patient regarding adherence and monitoring for adverse effects.
Evaluation: Continual assessment of viral load, hepatic function, and side effects.
Patient/Family Teaching
- Take medication exactly as prescribed with food.
- Report signs of rash, jaundice, severe fatigue, or anemia.
- Avoid organ transplant rejection drugs without consulting a healthcare provider.
Special Considerations
Black Box Warnings:
- Serious skin reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis.
- Hepatotoxicity.
Genetic Factors: None specified.
Lab Test Interference: May cause falsely elevated cholesterol levels.
Overdose Management
Signs/Symptoms: N/A due to limited overdose data.
Treatment: Supportive care; eliminate drug exposure; no specific antidote.
Storage and Handling
Storage: Store at 20-25°C (68-77°F), protected from light.
Stability: Stable under recommended conditions.