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Cobicistat

Generic name: cobicistat [ koe-BIK-i-stat ]
Brand name: Tybost
Dosage form: oral tablet (150 mg)
Drug class: Antiviral boosters

Medically reviewed by Drugs.com on Sep 11, 2023. Written by Cerner Multum.

What is cobicistat?

Cobicistat is given together with atazanavir (Reyataz) or darunavir (Prezista) to treat human immunodeficiency virus (HIV), the virus that can cause acquired immunodeficiency syndrome (AIDS).

Cobicistat is used to increase your blood levels of these medicines, helping to make them safer and more effective at lower doses.

Cobicistat is not an antiviral medicine and will not treat HIV or AIDS. Cobicistat is given only to help increase your blood levels of atazanavir or darunavir.

When given with atazanavir, cobicistat is for use in adults and children weighing at least 77 pounds (35 kilograms). When given with darunavir, cobicistat is for use in adults and children weighing at least 88 pounds (40 kilograms).

Cobicistat may also be used for purposes not listed in this medication guide.

Cobicistat side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Cobicistat may cause serious side effects. Call your doctor at once if you have:

Common side effects of cobicistat may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Warnings

Cobicistat is not a complete treatment and must be used in combination only with atazanavir or darunavir.

Tell your doctor about all your current medicines and any you start or stop using. Many drugs can interact with cobicistat and cause dangerous effects that could lead to death.

Before taking this medicine

Cobicistat is not a complete treatment and must be used in combination only with atazanavir or darunavir. You should not take cobicistat with any other antiviral medicines that your doctor has not prescribed.

You should not take cobicistat if you are allergic to it.

Many drugs can interact and cause dangerous effects that could lead to death. Some drugs should not be used together.

You should not take cobicistat with atazanavir if you also take:

You should not take cobicistat with atazanavir or darunavir if you also take:

You may not be able to take cobicistat if you also take:

Tell your doctor if you have ever had:

Cobicistat may not work as well if you take it during pregnancy. Do not start taking the medicine if you are pregnant. Tell your doctor right away if you become pregnant.

If you plan to get pregnant, ask your doctor for another antiviral medicine to use during pregnancy. Use all medications properly to control your infection. HIV can be passed to your baby if the virus is not controlled during pregnancy. Your name may be listed on a registry to track any effects of antiviral medicine on the baby.

If you do not plan to get pregnant, ask your doctor about using a non-hormonal birth control (condom, diaphragm with spermicide) to prevent pregnancy. Cobicistat can increase certain side effects when taken with hormonal birth control (pills, injections, implants, skin patches, vaginal rings).

Women with HIV or AIDS should not breastfeed a baby. Even if your baby is born without HIV, the virus may be passed to the baby in your breast milk.

How should I take cobicistat?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Cobicistat is usually taken once per day with atazanavir or darunavir.

Take your HIV medicines with food at the same time each day to be sure you do not miss a dose.

If you take cobicistat with atazanavir and you also take medicine to reduce stomach acid, follow these recommendations unless your doctor tells you otherwise:

You will need frequent medical tests.

Use all HIV medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice. Every person with HIV should remain under the care of a doctor.

Store in the original container at room temperature, away from moisture and heat. Keep the bottle tightly closed when not in use.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Get your prescription refilled before you run out of medicine completely.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking cobicistat?

Using cobicistat will not prevent your disease from spreading. Do not have unprotected sex or share razors or toothbrushes. Talk with your doctor about safe ways to prevent HIV transmission during sex. Sharing drug or medicine needles is never safe, even for a healthy person.

What other drugs will affect cobicistat?

When you start or stop taking cobicistat, your doctor may need to adjust the doses of any other medicines you take on a regular basis.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Tell your doctor about all your current antiviral medicines.

Many drugs can affect cobicistat, and some drugs should not be used at the same time. Tell your doctor about all your current medicines and any medicine you start or stop using. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.

Frequently asked questions

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.