Biktarvy Bictegravir Sodium Emtricitabine and Tenofovir Alafenamide Fumarate Tablets

1. Indications and Usage
HIV-1 Infection: Indicated as a complete regimen for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in adults and adolescents who currently have no treatment-experienced resistance to integrase inhibitors, emtricitabine, or tenofovir alafenamide.
2. Dosage and Administration
Recommended Dosage: The recommended dose for adults and adolescents (age 12 years and older and weighing at least 35 kg) is one tablet taken orally once daily.
Administration Requirements: The tablets can be taken with or without food. Do not chew, crush, or split the film-coated tablets.
Missed Doses: If a dose is missed within 18 hours of the usual time, take the missed dose as soon as possible and resume the normal schedule. If more than 18 hours have passed, do not take the missed dose; resume the usual schedule.
Vomiting: If vomiting occurs within 1 hour of taking a dose, take another tablet. If vomiting occurs more than 1 hour after taking a dose, do not take an extra tablet.
Renal Impairment: No dosage adjustment is required for estimated creatinine clearance (CrCl) ≥30 mL/min. Initiation is not recommended for patients with CrCl <30 mL/min.
Hepatic Impairment: No dosage adjustment is required for mild (Child-Pugh A) or moderate (Child-Pugh B) hepatic impairment. It is not recommended for severe (Child-Pugh C) hepatic impairment.
3. Mechanism of Action
Bictegravir: A next-generation integrase strand transfer inhibitor (INSTI) that inhibits the integration of HIV-1 DNA into the host cell genome.
Emtricitabine: A cytosine analogue (NRTI) that inhibits HIV-1 reverse transcriptase after being phosphorylated to its active triphosphate form.
Tenofovir Alafenamide: A nucleotide analogue (NRTI) of L-alanine, phenylalamine ester that inhibits HIV-1 reverse transcriptase and HBV polymerase.
4. Safety and Warnings
Immune Reconstitution Inflammatory Syndrome (IRIS): In HIV-1 patients with severe immunodeficiency at the time of starting antiretroviral treatment, an inflammatory response to asymptomatic or residual opportunistic infections may occur.
Hepatic Effects: Severe acute exacerbations of hepatitis B have been reported in patients coinfected with HIV-1 and HBV who discontinue emtricitabine or tenofovir alafenamide.
Renal Toxicity: New onset or worsening renal impairment, including acute renal failure and Fanconi syndrome (renal tubular injury with severe hypophosphatemia), has been reported with tenofovir alafenamide.
Fat Redistribution: Central adipose tissue redistribution has been reported in patients receiving antiretroviral therapy.
5. Adverse Reactions and Clinical Research
Adverse Reactions: The most common adverse reactions (incidence ≥5%) include headache, diarrhea, and nausea. Other reported adverse reactions include fatigue, insomnia, and depression.
Clinical Research: Clinical trials have demonstrated that this fixed-dose combination is effective in achieving and maintaining viral suppression in previously untreated HIV-1 infected adults and adolescents.
6. Drug Interactions
Antacids and Multivitamins: Dose separation is required. Bictegravir should be taken at least 2 hours before or 6 hours after oral antacids containing magnesium or aluminum, or oral supplements containing iron or calcium.
CYP Substrates: Bictegravir is a substrate of CYP3A; strong inducers of CYP3A may decrease bictegravir plasma concentrations.
Renal Transport Substrates: Concomitant use with drugs that compete for renal transport (e.g., tenofovir, adefovir) may increase the risk of renal toxicity.
7. Pharmaceutical Information
Composition: Each tablet contains bictegravir sodium (equivalent to 50 mg bictegravir), emtricitabine (200 mg), and tenofovir alafenamide fumarate (equivalent to 25 mg tenofovir alafenamide).
Appearance: The tablet is a bilayer film-coated tablet, white or off-white on one side and yellow on the other.
Storage: Store at 20°C to 25°C (68°F to 77°F). Protect from moisture.