Drug Guide
Elvitegravir
Classification
Therapeutic: Antiretroviral Agent
Pharmacological: Integrase Strand Transfer Inhibitor
FDA Approved Indications
- Treatment of HIV-1 infection
Mechanism of Action
Elvitegravir inhibits the HIV integrase enzyme, preventing the integration of viral DNA into the host cell genome, thereby hindering viral replication.
Dosage and Administration
Adult: Typically 85 mg once daily in combination with other antiretroviral agents. Dose adjustments may be needed based on coadministration with other drugs.
Pediatric: Not approved for pediatric use.
Geriatric: No specific dosage adjustments indicated, but caution advised due to potential comorbidities and concomitant medications.
Renal Impairment: Adjustments may be necessary; assess renal function before initiation and periodically during treatment.
Hepatic Impairment: No specific dosing recommendations; use with caution.
Pharmacokinetics
Absorption: Absorption is enhanced when taken with food.
Distribution: Widely distributed in tissues, plasma protein binding approximately 99%.
Metabolism: Metabolized primarily by CYP3A4 and UGT1A1 pathways.
Excretion: Primarily excreted in feces, minimal urinary excretion.
Half Life: Approximately 3 to 4 hours.
Contraindications
- Hypersensitivity to elvitegravir or components.
- Co-administration with drugs highly dependent on CYP3A4 for clearance and with a narrow therapeutic window.
Precautions
- Use with caution in patients with pre-existing liver disease, especially hepatitis B or C. Monitor liver function tests regularly.
Adverse Reactions - Common
- Nausea (Frequent)
- Diarrhea (Frequent)
- Headache (Frequent)
Adverse Reactions - Serious
- Lactic acidosis (Rare)
- Hepatotoxicity (Rare)
- Allergic reactions including rash or hypersensitivity (Rare)
Drug-Drug Interactions
- Rifampin (significantly reduces elvitegravir levels).
- CYP3A4 inhibitors or inducers (alter elvitegravir plasma levels).
- Other antiretrovirals, especially those with overlapping toxicities.
Drug-Food Interactions
- No significant interactions reported, but take with food to enhance absorption.
Drug-Herb Interactions
- St. John’s Wort (reduces effectiveness).
Nursing Implications
Assessment: Monitor HIV viral load, CD4 counts, liver function tests, and renal function periodically.
Diagnoses:
- Risk for ineffective tissue perfusion related to HIV infection.
- Risk for imbalanced fluid volume.
Implementation: Ensure medication adherence, monitor for side effects, educate patient on importance of compliance and reporting adverse effects.
Evaluation: Assess viral load suppression, side effect profile, and hepatic and renal function over time.
Patient/Family Teaching
- Take medication exactly as prescribed, with food.
- Report any signs of allergic reactions, severe rash, or hepatotoxicity.
- Use consistent dosing schedule and do not stop abruptly.
- Inform healthcare provider about all medications and supplements.
Special Considerations
Black Box Warnings:
- None specifically for elvitegravir, but caution with co-administration of drugs affecting renal function and increased risk of lactic acidosis.
Genetic Factors: Consider testing for HLA-B*5701 allele in some antiretroviral therapies; no specific association with elvitegravir.
Lab Test Interference: May increase serum creatinine without affecting actual renal function.
Overdose Management
Signs/Symptoms: Unknown; may include nausea, vomiting, or other nonspecific symptoms.
Treatment: Supportive care, monitor vitals, and manage symptoms. No specific antidote.
Storage and Handling
Storage: Store at room temperature 20-25°C (68-77°F). Keep container tightly closed.
Stability: Stable under recommended storage conditions for the duration specified on the packaging.