Drug Detail:Biktarvy (Bictegravir, emtricitabine, tenofovir [ bik-teg-ra-vir, em-trye-sye-ta-been, and-ten-of-oh-vir- ])
Drug Class: Antiviral combinations
1. How it works
- Biktarvy is a combination tablet that contains three antiviral agents: bictegravir, emtricitabine, and tenofovir alafenamide that may be used to treat human immunodeficiency virus type 1 (HIV-1).
- Each one of the antiviral agents contained in Biktarvy has a slightly different way of working. Bictegravir inhibits an enzyme that is required by HIV to replicate, called HIV-1 integrase. Bictegravir belongs to the class of medicines known as integrase strand transfer inhibitors (INSTIs). Emtricitabine inhibits another HIV enzyme, called HIV-1 reverse transcriptase that copies HIV RNA into new viral DNA. Emtricitabine belongs to the class of medicines called nucleoside reverse transcriptase inhibitors (NRTIs). Tenofovir alafenamide is a prodrug of tenofovir that inhibits HIV-1 replication by inhibiting an enzyme called reverse transcriptase, which is used by HIV-infected cells to make new viruses. Tenofovir belongs to the class of medicines called nucleoside reverse transcriptase inhibitors (NRTIs).
- Biktarvy belongs to the class of medicines known as antiviral combinations.
2. Upsides
- May be used to treat adults and children infected with HIV-1 who weigh 25kg (55lb) or more and have never taken antiretroviral medicines before.
- May also be used by those replacing their current antiretroviral medicines that they have been stable on as long as they have viral suppression (this means that the HIV-1 virus levels are less than 50 copies per mL), and no history of treatment failure in the past with other HIV medicines including the 3 antivirals contained in Biktarvy (namely bictegravir sodium, emtricitabine, and tenofovir alafenamide fumarate).
- Taken once a day, every day.
- May be taken with or without food.
- Approved as a complete regimen.
- Effective at reducing the number of HIV viruses in the blood to an undetectable level (which is less than 50 copies /mL). This reduces the transmission of the virus from one person to another.
- With fewer HIV-1 viruses in the body, the CD4 T-cell count increases, so that the immune system is more able to fight infection and illness, which keeps a person well.
- If taken as directed, there is less chance of HIV becoming drug-resistant.
- Contains the integrase strand transfer inhibitor (INSTI) bictegravir, along with the nucleoside analog reverse transcriptase inhibitors (NRTIs) emtricitabine (FTC), and tenofovir alafenamide (TAF).
- Well tolerated; side effects only affect around 6% of patients.
3. Downsides
If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:
- Diarrhea, nausea, and headache are the most common side effects reported. Side effects are uncommon and generally reported in < 6% of people taking Biktarvy. About 2% to 3% of patients report elevated cholesterol levels. Rarely, serious side effects may occur, including immune system changes; kidney problems; liver problems; or lactic acidosis.
- Not used as pre-exposure prophylaxis (PrEP) (to prevent HIV infection) or as post-exposure prophylaxis (PEP) (immediately after exposure). Biktarvy is only used for the treatment of HIV-1.
- May not be suitable for people with liver disease, including hepatitis B virus (HBV), kidney impairment, or osteoporosis. Not recommended in patients with severe renal impairment (estimated CrCl < 30 mL/min) or severe hepatic impairment (Child-Pugh Class C).
- Because Biktarvy contains three different medications this risk of drug interactions is reasonably high.
- Although weight gain is not listed as a side effect of Biktarvy, a large meta-analysis associated bictegravir, a component of Biktarvy, with significant weight gain alongside several other HIV medications. The risk appears higher in people with a lower baseline CD4 cell count (< 200 cells/mm3), lower baseline weight or body mass index (BMI), and African American race. Studies have demonstrated a median weight gain of between 1 kg (2.2 lbs) and 4 (8.8 lbs) kg over one to two years of follow-up. However, some patients have seen a >10% weight gain.
- Elevated cholesterol levels (eg, LDL cholesterol > 190 mg/dL) has been reported in 2% to 3% of patients.
- Severe exacerbations of hepatitis B have been reported in people who have a current or prior hepatitis B virus (HBV) infection and HIV and have discontinued products such as Biktarvy. Closely monitor liver function and initiate hepatitis B treatment if appropriate. Test for hepatitis B before starting Biktarvy.
- Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy.
- There is insufficient data on using Biktarvy in pregnant women. Enroll women who become pregnant while taking Biktarvy on the Antiretroviral pregnancy registry (APR) at 1-800-258-4263. The CDC recommends women with HIV-1 should not breastfeed their infants to avoid the risk of postnatal transmission of HIV-1.
- Does not cure HIV-1. Tablets must be taken life-long.
- No generic available.is
Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects
4. Tips
- Take Biktarvy once a day, every day. You may take it with food or without food. Do not miss any doses.
- If you miss a dose of Biktarvy, take the missed dose as soon as you remember. If it is almost time for your next dose, just skip the missed dose and take your next dose at the regular time. Do not use two doses at one time to make up for a missed dose.
- If you take antacids that contain aluminum or magnesium, you should take your Biktarvy at least 2 hours before or 6 hours after you take these antacids.
- If you take supplements or antacids that contain iron or calcium, take Biktarvy with food at the same time that you take these supplements or antacids.
- Before you start taking Biktarvy your doctor will test you for hepatitis B virus (HBV) infection. This is because treating HCV may reactivate an underlying hepatitis B infection (HBV). Any underlying HBV infection should be treated before Biktarvy is started.
- Seek urgent medical attention if you develop a very slow heartbeat, feel faint or unwell, or experience symptoms such as dizziness or lightheadedness, weakness, excessive tiredness, shortness of breath, chest pains, confusion, or memory problems. Also see your doctor if you develop other worrying symptoms such as dark urine, abdominal pain, vomiting blood, yellowing of the skin or eyes, or you bleed or bruise more often than normal.
- Talk to your doctor or pharmacist before taking any new medication including supplements brought over the counter such as calcium. Biktarvy can also cause problems if you have certain medical conditions, such as liver disease, kidney disease, or osteoporosis.
- It is not known what effects Biktarvy has on the developing fetus in pregnant women. If you are or become pregnant while taking Biktarvy enroll on the Antiretroviral pregnancy registry (APR) at 1-800-258-4263. The CDC recommends women with HIV-1 should not breastfeed their infants to avoid the risk of postnatal transmission of HIV-1.
5. Response and effectiveness
- Usually starts working within the first 4 weeks, with a noticeable reduction in HIV viral load (the amount of HIV in your blood). Within three to six months, the viral load in most people falls to an undetectable level. The CD4+ T-cell count usually increases gradually.
- In one trial after 48 weeks 92.4 % of patients had a viral load of <50 copies/mL and 87.6% had a viral load of <20 copies/mL. The mean increase in CD4+ T-cell count was 233 cells/µL.
6. Interactions
Medicines that interact with Biktarvy may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with Biktarvy. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.
Biktarvy interacts with over 360 drugs and most of these interactions are considered moderate or major. Common medications that may interact with Biktarvy include:
- antacids that contain aluminum or magnesium (take Biktavry at least 2 hours before or 6 hours after you take these antacids)
- anticonvulsants, such as carbamazepine, phenytoin or phenobarbital
- antimicrobials, such as rifampin (contraindicated)
- atazanavir (contraindicated)
- dofetilide (avoid)
- cyclosporine
- other HIV medications, such as darunavir, efavirenz, lopinavir, tenofovir, tipranavir, or ritonovir (avoid)
- inducers of P-glycoprotein such as carbamazepine, dexamethasone, doxorubicin, nefazodone, phenobarbital, phenytoin, prazosin, rifampicin, St. John's wort, tenofovir, tipranavir, trazodone, and vinblastine
- medicines that are substrates of breast cancer resistance protein (BCRP)
- metformin
- rifabutin, rifapentine (not recommended)
- St. John's Wort (not recommended)
- supplements that contain magnesium, aluminum, calcium, and iron (including certain antacids, laxatives, sucralfate, and buffered medications) (may lower effectiveness for HIV and cause viral resistance)
- other drugs that are substrates of organic cation transporter 2 (OCT2), multidrug and toxin extrusion transporter 1 (MATE1), cytochrome P450 3A (CYP3A), or UDP-glucuronosyltransferase 1A1 (UGT1A1).
Because emtricitabine and tenofovir, two components of Biktarvy, are primarily excreted by the kidneys, coadministration of Biktarvy with drugs that are eliminated through the kidneys may increase the risk of adverse effects. Examples include acyclovir, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple nonsteroidal antiinflammatory drugs (NSAIDs) such as ibuprofen or naproxen.
Note that this list is not all-inclusive and includes only common medications that may interact with Biktarvy. You should refer to the prescribing information for Biktarvy for a complete list of interactions.