Composition and mechanism of action
ERESTZ is a combination antiretroviral therapy (ART) in a single, once-daily tablet. It is comprised of three distinct active ingredients, each targeting the human immunodeficiency virus (HIV) life cycle in a specific way:
- Emtricitabine (NRTI): A nucleoside reverse transcriptase inhibitor (NRTI) that is incorporated into the viral DNA chain by the reverse transcriptase enzyme, halting viral replication.
- Rilpivirine (NNRTI): A non-nucleoside reverse transcriptase inhibitor (NNRTI) that binds directly to the reverse transcriptase enzyme, disrupting its function and stopping viral DNA synthesis.
- Tenofovir Disoproxil Fumarate (NRTI): A nucleotide reverse transcriptase inhibitor (NRTI) that also inhibits the reverse transcriptase enzyme. Combining these agents provides a powerful and convenient treatment that helps suppress the virus effectively, a cornerstone of modern HIV management.
Therapeutic indications and administration
ERESTZ is indicated for treating HIV-1 infection in adults under specific conditions and should be prescribed by an HIV expert. It is used as initial therapy for adults with a viral load up to 100,000 copies/mL and as a replacement in virologically suppressed individuals with no history of treatment failure or resistance to its components. The medication is taken once daily with food, which is essential for proper absorption. Strict adherence to the prescribed regimen is crucial to prevent drug resistance.
Potential side effects and contraindications
Erestz can cause side effects ranging from common to serious. Patients should discuss these with their healthcare provider.
Common side effects
Common side effects may include nausea, diarrhea, headache, dizziness, drowsiness, insomnia, abnormal dreams, rash, and changes in appetite.
Serious side effects and warnings
Serious side effects include rare but potentially fatal lactic acidosis and severe hepatomegaly with steatosis. Discontinuing Erestz in patients with co-occurring Hepatitis B (HBV) can cause severe HBV exacerbations, requiring liver function monitoring. Tenofovir can cause kidney problems, necessitating regular kidney health checks. Bone problems like density loss and fractures have been reported. Rilpivirine is associated with severe depressive symptoms, and patients experiencing mood changes should seek medical evaluation.
Contraindications
Erestz is contraindicated in patients with hypersensitivity to its ingredients. It should not be used with certain medications, including other NNRTIs and strong CYP3A enzyme inducers like carbamazepine, rifampicin, and St. John's Wort.
Comparison of Erestz and Atripla
Erestz and Atripla are both single-pill, once-daily HIV-1 treatments, but differ in their NNRTI component, leading to variations in side effects and usage.
| Feature | Erestz | Atripla (Generic: Efavirenz/Emtricitabine/Tenofovir) |
|---|---|---|
| NRTI Components | Emtricitabine and Tenofovir Disoproxil Fumarate | Emtricitabine and Tenofovir Disoproxil Fumarate |
| NNRTI Component | Rilpivirine | Efavirenz |
| Food Requirement | Must be taken with food | Often recommended at bedtime on an empty stomach due to potential neurological side effects of efavirenz |
| CNS Side Effects | Associated with depressive disorders and other mood changes | Commonly causes dizziness, abnormal dreams, and other neurological issues |
| Initial Viral Load | Recommended for patients with a viral load $\le$ 100,000 copies/mL at baseline | No such viral load restriction. |
| Drug Interactions | Contraindicated with strong CYP3A inducers (e.g., rifampicin, carbamazepine) and proton pump inhibitors | Contraindicated with certain medications metabolized by CYP enzymes |
Conclusion
ERESTZ is an effective single-pill option for HIV-1 treatment, combining three antiretroviral agents to suppress the virus. It is indicated for specific patient groups, and consistent daily dosing is crucial for effectiveness and preventing resistance. Monitoring for potential side effects, particularly concerning kidney, liver, and mental health, is important. Erestz simplifies treatment while providing potent viral control for individuals with HIV. For further information, consult resources like the U.S. National Institutes of Health.
