Drug Database: Cobicistat

What is cobicistat?What is cobicistat?

What is cobicistat?

Cobicistat (brand name: Tybost) is a prescription medicine approved by the U.S. Food and Drug Administration (FDA) for use in adults and children along with the HIV medicines atazanavir (brand name Reyataz) or darunavir (brand name Prezista). Cobicistat is not active against HIV and is only used as a pharmacokinetic enhancer to boost the activity of other HIV medicines.

• When taken with atazanavir, cobicistat is approved for use in adults and children who weigh at least 77 lb (35 kg).  (A fixed-dose combination tablet containing atazanavir and cobicistat [brand name: Evotaz] is also available.)
• When taken with darunavir, cobicistat is approved for use in adults and children who weigh at least 88 lb (40 kg). (A fixed-dose combination tablet containing darunavir and cobicistat [brand name: Prezcobix] is also available.)

For more information on the use of cobicistat in people with HIV, please refer to the Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents with HIV and the Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection.

Cobicistat is not an antiretroviral medicine and does not treat HIV. Even if you take cobicistat and atazanavir or darunavir, you must also take all the HIV medicines prescribed by your health care provider. Do not cut down on, skip, or stop taking cobicistat or any HIV medicines unless your health care provider tells you to.

What should I tell my health care provider before taking cobicistat?What should I tell my health care provider before taking cobicistat?

What should I tell my health care provider before taking cobicistat?

Before taking cobicistat, tell your health care provider:

• If you are allergic to cobicistat, atazanavir, darunavir, or any other medicines. 
• If you have kidney problems.
• If you have liver problems.
• If you have any other medical conditions.
• If you are pregnant or plan to become pregnant. Talk to your health care provider about the risks and benefits of taking cobicistat during pregnancy. For more information on the use of cobicistat during pregnancy, please refer to the Recommendations for the Use of Antiretroviral Drugs During Pregnancy and Interventions to Reduce Perinatal HIV Transmission in the United States.
• If you are breast/chestfeeding or plan to breast/chestfeed. For people with HIV in the United States, the Guideline recommends speaking with your health care provider to discuss options for feeding your baby. People with suppressed viral load have a less than 1% chance of transmitting HIV to their baby via their own milk. 
• If you are using hormone-based birth control (such as pills, implants, or vaginal rings). Cobicistat may make these forms of birth control less effective. Your health care provider can help you decide how to adjust your birth control while you are taking cobicistat. For more information about using birth control and HIV medicines at the same time, view the HIVinfo HIV and Birth Control infographic.
• About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products (including St. John's wort) you are taking or plan to take. Cobicistat may affect the way other medicines or products work, and other medicines or products may affect how cobicistat works. Taking cobicistat together with atazanavir or darunavir and certain other medicines may cause serious or life-threatening side effects.

How should I take cobicistat?How should I take cobicistat?

How should I take cobicistat?

Cobicistat comes in tablet form. Each tablet contains 150 mg of cobicistat.

Take cobicistat according to your health care provider’s instructions. Do not miss a dose of cobicistat, and do not change your dose or stop taking cobicistat without first talking with your health care provider.

Take cobicistat once each day at the same time you take atazanavir or darunavir. It is important to take these medicines on a regular dosing schedule.

Take cobicistat and atazanavir or darunavir by mouth with food.

If you take cobicistat with atazanavir and also take antacids or H2 blockers (medicines for reducing stomach acid), carefully follow instructions on how to take them with cobicistat and atazanavir.

If you take cobicistat with atazanavir and also take proton-pump inhibitors (medicines for reducing stomach acid), check with your health care provider to find out if you can take these medicines with cobicistat and atazanavir. Certain people should NOT take proton-pump inhibitors during treatment with cobicistat and atazanavir. If your health care provider tells you to continue taking proton-pump inhibitors, carefully follow instructions on how to take them with cobicistat and atazanavir.

If you have taken too much cobicistat, contact your health care provider or local poison control center (1-800-222-1222 or online) right away, or go to the nearest hospital emergency room.

For more information on how to take cobicistat, see the FDA drug label.

What should I do if I forget a dose?What should I do if I forget a dose?

What should I do if I forget a dose?

If you miss a dose of cobicistat, take the missed dose as soon as you remember it. But if it is almost time for your next dose, skip the missed dose and just take your next dose at the regular time. Do not take two doses at the same time to make up for the missed dose.

What side effects can cobicistat cause?What side effects can cobicistat cause?

What side effects can cobicistat cause?

Cobicistat may cause side effects. Some side effects of cobicistat can be serious as noted above. Many side effects from HIV medicines, such as nausea or occasional dizziness, are manageable. See the HIVinfo fact sheet on HIV Medicines and Side Effects for more information.  

When cobicistat is taken with atazanavir, the most common side effects include yellowing of your skin or the whites of your eyes (jaundice) and rash.

Tell your health care provider if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of cobicistat. To learn more about possible side effects of cobicistat, read the drug label or package insert or talk to your health care provider or pharmacist.

You can report side effects to FDA at 1-800-FDA-1088 (1-800-332-1088) or online.

How should cobicistat be stored?How should cobicistat be stored?

How should cobicistat be stored?

• Store cobicistat at room temperature, 68°F to 77°F (20°C to 25°C).
• Keep cobicistat in the container that it came in and keep the container tightly closed. If the container has a small packet of drying agent (called a desiccant), do not remove it. The desiccant protects the medicine from moisture.
• Do not use cobicistat if the original seal over the container opening is broken or missing.
• Throw away cobicistat that is no longer needed or expired (out of date). Follow FDA guidelines on how to safely dispose of unused medicine.
• Keep cobicistat and all medicines out of reach of children.

Where can I find more information about cobicistat?Where can I find more information about cobicistat?

Where can I find more information about cobicistat?

• For more information on the use of cobicistat in people with HIV, please refer to the Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents with HIV and the Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection.
• This Patient Version drug summary is based on the following FDA label(s): Tablet (film coated). The Patient Package Insert includes information for people taking cobicistat.
• The American Hospital Formulary Service (AHFS) Patient Medication Information for cobicistat available from MedlinePlus.  
• Cobicistat-related research studies, from ClinicalTrials.gov. (The ClinicalTrials.gov search can be modified so that you can get results that better match your interests.)
• A list of FDA-approved HIV medicines, from HIVinfo.