bictegraviremtricitabintenofovir

Bictegraviremtricitabintenofovir, commonly referred to as Biktarvy, is a fixed-dose combination antiretroviral medication used to treat HIV-1 infection. It combines three agents in a single tablet: bictegravir 50 mg, emtricitabine 200 mg, and tenofovir alafenamide (TAF) 25 mg. The tablet is taken once daily, with or without food.

Mechanism of action: Bictegravir is an integrase strand transfer inhibitor (INSTI) that blocks integration of HIV DNA into the host genome. Emtricitabine and tenofovir alafenamide are nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) that inhibit reverse transcription. Tenofovir alafenamide delivers active tenofovir diphosphate into HIV-infected cells with lower systemic exposure than tenofovir disoproxil fumarate, reducing some long-term toxicity while maintaining antiviral activity.

Indications and regimen: The product is indicated for the treatment of HIV-1 infection in adults and certain pediatric patients weighing at least 25 kg, as a complete regimen for antiretroviral therapy or as a switch regimen for virologically suppressed patients stable on this combination. It is not active against HIV-2.

Administration and safety: The dose is one tablet once daily, with or without food. Not recommended below an estimated glomerular filtration rate of 30 mL/min. Common adverse effects include diarrhea, nausea, fatigue, and headache. Serious events may include hepatotoxicity and lactic acidosis; these are rare. Tenofovir alafenamide is associated with less bone and renal toxicity than tenofovir disoproxil fumarate. Potent enzyme inducers (for example rifampin) can lower bictegravir levels; coadministration is generally not recommended.

Monitoring: Patients require regular monitoring of HIV-1 RNA levels, CD4 counts, renal function, and liver enzymes to assess efficacy and safety. The regimen has a high barrier to resistance when taken as prescribed.