August 30, 2012
Stribild is a tablet that contains three drugs used to fight HIV: emtricitabine (Emtriva, see Fact Sheet 420), tenofovir (Viread, see Fact Sheet 419), and elvitegravir (see Fact Sheet 472), plus cobicistat, which boosts blood levels of elvitegravir but does not directly work against HIV.
The drugs in Stribild are an integrase inhibitor (elvitegravir, 150 mg) paired with a new booster, cobicistat (150 mg.) They are combined with two nucleoside analog reverse transcriptase inhibitors, or nukes (emtricitabine, 200 mg and tenofovir, 300 mg).
When HIV infects a cell, it combines its genetic code into the cell's own code. This is shown in fact sheet 400, step 5. Elvitegravir blocks this process. When elvitegravir blocks integration, HIV infects a cell but cannot make more copies of itself. Cobicistat is a booster. It increases the blood levels of elvitegravir. It does not directly work against HIV.
Stribild was approved in 2012 as an ARV for adults with HIV infection who have not yet taken any antiretroviral drugs. The FDA is requiring Gilead to study the drug's safety in women and children. People with liver or kidney problems may not be able to take Stribild.
There are no absolute rules about when to start antiretroviral therapy (ART). You and your health care provider should consider your CD4 cell count, your viral load, any symptoms you are having, and your attitude about taking ART. Fact Sheet 404 has more information about guidelines for the use of ART.
If you take Stribild, you can reduce your viral load to extremely low levels, and increase your CD4 cell counts. This should mean staying healthier longer.
Stribild provides a complete antiviral regimen in one pill. It can be more convenient to use Stribild than some other combinations of drugs. This could mean fewer missed doses and better control of HIV.
Many new copies of HIV are mutations. They are slightly different from the original virus. Some mutations can keep multiplying even when you are taking an ARV. When this happens, the drug will stop working. This is called "developing resistance" to the drug. See Fact Sheet 126 for more information on resistance.
Sometimes, if your virus develops resistance to one drug, it will also have resistance to other ARVs. This is called "cross-resistance." It is likely that HIV that has developed resistance to raltegravir (see Fact Sheet 471) will also be resistant to elvitegravir.
Resistance can develop quickly. It is very important to take ARVs according to instructions, on schedule, and not to skip or reduce doses.
Stribild is taken by mouth as a tablet. The normal adult dose is one tablet, once a day with food. If you miss your dose, you can take Stribild up to 12 hours late. Otherwise, take your next dose at the regular time. Take Stribild and antacids at least 2 hours apart.
When you start any ART, you may have temporary side effects such as headaches, high blood pressure, or a general sense of feeling ill. These side effects usually get better or disappear over time.
The most common side effects of Stribild are the same as with the drugs it contains: elvitegravir (see Fact Sheet 472), emtricitabine (see Fact Sheet 420), and tenofovir (see Fact Sheet 419). They include headache, diarrhea, nausea, vomiting, vivid dreams, anxiety, rash, dizziness, insomnia, and loss of appetite.
Tenofovir can cause kidney damage. Creatinine levels should be monitored in people taking tenofovir. Tenofovir can also damage the liver. People taking tenofovir should have their liver health monitored. Tenofovir can reduce bone mineral density (see Fact Sheet 557).
Stribild is not approved for the treatment of chronic hepatitis B virus (HBV) infection. Severe worsening of hepatitis B has been reported in patients who are coinfected with HBV and HIV-1 and have stopped Emtriva or Viread, which are components of Stribild. If you have had hepatitis B or C, your liver function tests may increase significantly. These should be monitored carefully.
Stribild can interact with other drugs or supplements you are taking. These interactions can change the amount of each drug in your bloodstream and cause an under- or overdose. New interactions are constantly being identified. Make sure that your health care provider knows about ALL drugs and supplements you are taking.
Gilead will conduct additional studies of Stribild's safety in women and children, how resistance develops, and the possibility of interactions between Stribild and other drugs. Drugs to watch out for include other ARVs, drugs to treat tuberculosis (see Fact Sheet 518), for erectile dysfunction (such as Viagra), for heart rhythm (antiarrhythmics), and for migraine headaches. Interactions are also possible with several antihistamines (allergy medications), sedatives, drugs to lower cholesterol, and anti-fungal drugs.