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Generic Name: cobicistat and darunavir (koe BIK i stat and dar UE na vir)
Brand Name: Prezcobix

What is cobicistat and darunavir?

Darunavir is a protease (PRO-tee-ayz) inhibitor antiviral medication that prevents human immunodeficiency virus (HIV) cells from multiplying in your body. Cobicistat reduces the action of enzymes in your liver that break down certain antiviral medicines. This allows the antiviral medicines to be used more safely and effectively at lower doses.

Cobicistat and darunavir is a combination medicine given together with other antiviral medicines to treat human immunodeficiency virus (HIV) in adults. HIV is the virus that causes acquired immunodeficiency syndrome (AIDS). This medicine is not a cure for HIV or AIDS.

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

What is the most important information I should know about cobicistat and darunavir?

Serious drug interactions can occur when certain medicines are used together with cobicistat and darunavir. Tell each of your healthcare providers about all medicines you use now, and any medicine you start or stop using.

Call your doctor at once if you have signs of a serious side effect--upper stomach pain, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes), little or no urinating, swelling in your feet or ankles, feeling tired or short of breath, fever, swelling in your face or tongue, skin pain, or a skin rash that spreads and causes blistering and peeling.

What should I discuss with my healthcare provider before taking cobicistat and darunavir?

You should not take this medicine if you are allergic to cobicistat or darunavir.

Some medicines can interact with cobicistat and darunavir and should not be used at the same time. Your doctor may need to change your treatment plan if you use any of the following drugs:

  • alfuzosin;

  • cisapride;

  • colchicine;

  • dronedarone;

  • lovastatin, simvastatin;

  • lurasidone;

  • oral midazolam, triazolam;

  • pimozide;

  • ranolazine;

  • rifampin;

  • sildenafil (Revatio, for treating pulmonary arterial hypertension);

  • St. John's wort; or

  • ergot medicine--dihydroergotamine, ergotamine, ergonovine, methylergonovine.

To make sure cobicistat and darunavir is safe for you, tell your doctor if you have:

  • liver disease (especially hepatitis B or C);

  • kidney disease;

  • a bleeding or blood clotting disorder such as hemophilia;

  • an allergy to sulfa drugs;

  • diabetes; or

  • if you also take tenofovir.

This medicine is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant. HIV can be passed to your baby if you are not properly treated during pregnancy. Take all of your HIV medicines as directed to control your infection.

If you are pregnant, your name may be listed on a pregnancy registry. This is to track the outcome of the pregnancy and to evaluate any effects of cobicistat and darunavir on the baby.

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

Cobicistat and darunavir is not approved for use by anyone younger than 18 years old.

How should I take cobicistat and darunavir?

Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Take this medicine with food.

While using cobicistat and darunavir, your blood may need to be tested often. Your kidney and liver function may also need to be tested.

HIV/AIDS is usually treated with a combination of drugs. Use all medications as directed by your doctor. Read the medication guide or patient instructions provided with each medication. Do not change your doses or medication schedule without your doctor's advice. Every person with HIV or AIDS should remain under the care of a doctor.

Store 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 missed dose as soon as you remember. If you are more than 12 hours late, skip the missed dose and take your medicine at the next scheduled dose. Do not take extra medicine to make up the missed dose.

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 and darunavir?

If you also take enteric-coated didanosine (Videx EC), take it 1 hour before or 2 hours after you take cobicistat and darunavir.

Taking this medication will not prevent you from passing HIV to other people. 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.

Cobicistat and darunavir 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.

This medicine may increase your risk of certain infections or autoimmune disorders by changing the way your immune system works. Symptoms may occur weeks or months after you start treatment with cobicistat and darunavir. Tell your doctor if you have:

  • signs of a new infection--fever, night sweats, swollen glands, mouth sores, diarrhea, stomach pain, weight loss;

  • chest pain (especially when you breathe), dry cough, wheezing, feeling short of breath;

  • cold sores, sores on your genital or anal area;

  • rapid heart rate, feeling anxious or irritable, weakness or prickly feeling, problems with balance or eye movement;

  • trouble speaking or swallowing, severe lower back pain, loss of bladder or bowel control; or

  • swelling in your neck or throat (enlarged thyroid), menstrual changes, impotence, loss of interest in sex.

Call your doctor at once if you have:

  • high blood sugar--increased thirst, increased urination, hunger, dry mouth, fruity breath odor, drowsiness, dry skin, blurred vision, weight loss;

  • liver problems--upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); or

  • severe skin reaction--fever, sore throat, swelling in your face or tongue, burning or redness in your eyes, skin pain, warmth or redness under your skin, red or purple skin rash that spreads and causes blistering and peeling.

Common side effects may include:

  • nausea, vomiting, stomach pain, diarrhea

  • headache;

  • rash; or

  • changes in the shape or location of body fat (especially in your arms, legs, face, neck, breasts, and waist).

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.

See also: Side effects (in more detail)

What other drugs will affect cobicistat and darunavir?

Many drugs can interact with cobicistat and darunavir, and some drugs should not be used together. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide. Tell your doctor about all medicines you use, and those you start or stop using during your treatment with cobicistat and darunavir. Give a list of all your medicines to any healthcare provider who treats you.

Where can I get more information?

  • Your pharmacist can provide more information about cobicistat and darunavir.
  • 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.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 1.01.

Date modified: October 14, 2016
Last reviewed: March 20, 2015