What Type of Drug Is Elvitegravir?
Elvitegravir is an integrase inhibitor, a class of antiretroviral drugs for treating human immunodeficiency virus (HIV). It targets the integrase enzyme, which HIV uses to insert its DNA into host cells, thus preventing viral replication. Elvitegravir is not used alone but in combination with other antiretroviral medications and a boosting agent to enhance effectiveness and prevent resistance.
Mechanism of Action
Elvitegravir works as an integrase strand transfer inhibitor (INSTI), blocking the integration of viral DNA into the host cell's genome. This prevents the virus from producing new copies of itself, reducing the viral load and increasing CD4+ cell counts.
Combination Therapy with Elvitegravir
To be effective, elvitegravir is combined with other drugs. Cobicistat is used as a pharmacokinetic enhancer to boost elvitegravir levels in the body, allowing for once-daily dosing. Elvitegravir is primarily available in single-tablet regimens (STRs) for convenience:
- Stribild®: Contains elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (TDF).
- Genvoya®: Contains elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide (TAF).
Comparison of Elvitegravir Combinations
Stribild and Genvoya both treat HIV but use different forms of tenofovir with different safety profiles, particularly regarding kidney and bone health.
| Feature | Stribild (Elvitegravir + TDF) | Genvoya (Elvitegravir + TAF) |
|---|---|---|
| Tenofovir Formulation | Tenofovir Disoproxil Fumarate (TDF) | Tenofovir Alafenamide (TAF) |
| Tenofovir Dose | Higher (300 mg) | Lower (10 mg) |
| Renal Function Impact | Greater potential for kidney toxicity | Lower potential for kidney toxicity |
| Bone Mineral Density | Greater potential for decreased bone mineral density | Lower potential for decreased bone mineral density |
| Use Case | Historically used but less common now | Preferred for many patients due to improved safety profile |
Potential Side Effects and Drug Interactions
Elvitegravir regimens are generally well-tolerated, but side effects and drug interactions can occur, largely due to the presence of cobicistat.
Common Side Effects
Common side effects may include nausea, diarrhea, headache, fatigue, dizziness, and abnormal dreams.
Serious Side Effects
Less common but serious side effects include severe allergic reactions, kidney or liver problems, lactic acidosis, and changes in mental health. Immediate medical attention is required for these.
Important Drug Interactions
Cobicistat interacts with many medications. It's crucial to inform doctors about all drugs, supplements, and herbal products, as some are contraindicated, such as St. John's wort. Interactions can occur with anti-seizure medications, anticoagulants, cholesterol drugs, and corticosteroids, among others.
Conclusion
Elvitegravir is a key integrase inhibitor in HIV treatment, preventing viral replication by blocking the integrase enzyme. It is used in boosted, multi-drug single-tablet regimens like Stribild and Genvoya. The cobicistat booster enables convenient once-daily dosing but necessitates careful drug interaction management. Genvoya, containing TAF, offers better renal and bone safety compared to the TDF in Stribild. Adherence to treatment and open communication with healthcare providers about all medications are essential for successful treatment and avoiding dangerous interactions. Integrase inhibitor-based regimens are a significant advancement in managing HIV.
