Nurses Compass
Drug Guide
Etravirine
Classification
Therapeutic: Antiretroviral agent, HIV-1 non-nucleoside reverse transcriptase inhibitor (NNRTI)
Pharmacological: Nucleoside reverse transcriptase inhibitor
FDA Approved Indications
- Treatment of HIV-1 infection in combination with other antiretroviral agents
Mechanism of Action
Etravirine binds directly to reverse transcriptase enzyme, causing an enzyme conformational change that inhibits its activity, thereby preventing viral replication.
Dosage and Administration
Adult: 200 mg twice daily after meals
Pediatric: Not FDA approved for pediatric use
Geriatric: Adjust dosing based on hepatic function; no specific dose adjustments established solely based on age.
Renal Impairment: Use with caution; no specific adjustment recommended.
Hepatic Impairment: Use caution, especially in moderate to severe hepatic impairment; no specific dosing adjustments established.
Pharmacokinetics
Absorption: Rapidly absorbed with food, with increased bioavailability when taken with meals.
Distribution: Widely distributed; plasma protein binding ~99.7%.
Metabolism: Primarily metabolized in the liver via CYP3A4 and CYP2C9/19.
Excretion: Excreted mainly in feces; minimal renal excretion.
Half Life: approx. 49 hours.
Contraindications
- Co-administration with certain drugs metabolized by CYP3A4 or that have QT prolongation risk.
Precautions
- Use with caution in patients with known hypersensitivity, hepatic impairment, or QT prolongation risk.
- Monitor for drug interactions reducing efficacy or increasing toxicity.
Adverse Reactions - Common
- Rash (Common)
- Nausea (Common)
- Diarrhea (Common)
Adverse Reactions - Serious
- Hepatotoxicity (Less common)
- Hypersensitivity reactions (Rare)
- QT prolongation (Less common)
Drug-Drug Interactions
- CYP3A4 inducers and inhibitors (e.g., rifampin, ketoconazole, ritonavir)
- Other antiretrovirals, especially those affecting CYP enzymes
Drug-Food Interactions
- High-fat meals increase absorption, but should be taken consistently with food.
Drug-Herb Interactions
- St. John’s Wort and other herbal products inducing CYP3A4 could reduce efficacy.
Nursing Implications
Assessment: Monitor for signs of efficacy (viral load decreasing) and adverse effects. Assess hepatic function before and during therapy.
Diagnoses:
- Risk for infection due to immune suppression
- Risk for adverse drug reactions
Implementation: Administer with food; counsel patients on adherence.
Evaluation: Monitor viral load and CD4 counts; observe for adverse reactions and drug interactions.
Patient/Family Teaching
- Take medication with food to improve absorption.
- Do not alter dose or discontinue without healthcare provider’s advice.
- Report signs of rash, jaundice, or cardiovascular symptoms.
- Maintain regular follow-up appointments for LAB assessments.
Special Considerations
Black Box Warnings:
- Potential for severe skin reactions and hypersensitivity syndromes.
- QT prolongation and torsades de pointes.
Genetic Factors: Pharmacogenomic variations in CYP450 enzymes may alter drug levels.
Lab Test Interference: May interfere with laboratory measurement of serum laboratory parameters.
Overdose Management
Signs/Symptoms: Nausea, vomiting, dizziness, possible arrhythmias.
Treatment: Supportive care, activated charcoal if within 1 hour of ingestion, cardiac monitoring if QT prolongation is suspected.
Storage and Handling
Storage: Store at room temperature, 20°C to 25°C (68°F to 77°F).
Stability: Stable for the duration of the labeled shelf life when stored properly.