Atripla

Atripla is a fixed-dose combination antiretroviral medication used to treat HIV-1 infection. It contains three active ingredients in a single tablet: efavirenz 600 mg, emtricitabine 200 mg, and tenofovir disoproxil fumarate 300 mg. It was developed jointly by Bristol-Myers Squibb and Gilead Sciences and received U.S. FDA approval in 2006. The tablet is taken once daily.

Atripla is indicated for the treatment of HIV-1 infection in adults and in certain pediatric patients weighing at least 40 kg. It is not approved for HIV-2 infection or for pre-exposure prophylaxis. As a combination regimen, it is used as part of combination antiretroviral therapy to achieve and maintain viral suppression.

Mechanism of action: Emtricitabine and tenofovir disoproxil fumarate are nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), while efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI). By inhibiting reverse transcription, the trio reduces HIV replication and helps lower viral load.

Administration and dosing: The standard dose is one tablet once daily. Atripla should be taken on an empty stomach because high-fat meals can markedly increase efavirenz exposure and worsen adverse effects. Some patients may take it at bedtime to mitigate CNS-related side effects.

Side effects and safety: Common adverse effects include dizziness, sleep disturbances, abnormal dreams, fatigue, nausea, and rash. Serious consequences can include hepatotoxicity, lactic acidosis, and severe skin reactions. Long-term use of tenofovir disoproxil fumarate can affect kidney function and bone mineral density. Atripla is not recommended during pregnancy due to potential teratogenic risk; pregnancy should be planned with a healthcare provider.

Interactions and contraindications: Efavirenz induces multiple cytochrome P450 enzymes, leading to numerous drug interactions. Coadministration with strong inducers or inhibitors of these enzymes, certain anticonvulsants, hormonal contraceptives, rifamycins, or St. John’s wort should be avoided or carefully managed.

Regulatory status: Atripla remains a widely used first-line regimen, though newer TAF-containing therapies with improved renal and bone safety have become more common. Neuropsychiatric effects and suicidality warnings are noted in labeling.

---