Detailed information

Evotaz is a fixed-dose combination tablet containing 300mg of atazanavir and 150mg of cobicistat.

Atazanavir is an HIV protease inhibitor. Cobicistat is used to boost blood levels of atazanavir and has no antiviral activity of its own. Together, these drugs reduce the amount of HIV in the body and prevent the development of AIDS-defining illnesses. Evotaz received marketing approval in the United States in January 2015 and in the European Union in July 2015.


Evotaz was approved based on data showing equivalence between atazanavir boosted by cobicistat and atazanavir boosted by ritonavir. For further information on the effectiveness of boosted atazanavir, see atazanavir.

Taking it

The standard dose of Evotaz is one pink tablet taken once daily with food. Evotaz is approved for use in combination with two or more other antiretroviral drugs.

Evotaz should not be initiated in patients with creatinine clearance less than 70 ml/min if any co-administered agent (e.g. emtricitabine, lamivudine, tenofovir disoproxil fumarate) requires dose adjustment based on creatinine clearance.

Side effects

Common side effects of Evotaz include (most common in bold):

Yellowing of the skin or eyes (jaundice), nausea, increased appetite, sense of taste affected, dry mouth, headache, dizziness, insomnia (difficulty sleeping), abnormal dreams, somnolence (sleepiness), vomiting, diarrhoea, abdominal pain, indigestion, bloating, flatulence, increased levels of bilirubin in the blood, rash, fatigue.

A common side effect of Evotaz is the development of a rash. This is usually mild, but in rare cases it can be the sign of a more severe reaction.

Drug interactions

The use of cobicistat to boost blood levels of atazanavir means that drug interactions with other medications are somewhat different from those reported for atazanavir, due to the potential for interactions between both cobicistat and boosted atazanavir and other medications.


boosting agent

Booster drugs are used to ‘boost’ the effects of protease inhibitors and some other antiretrovirals. Adding a small dose of a booster drug to an antiretroviral makes the liver break down the primary drug more slowly, which means that it stays in the body for longer times or at higher levels. Without the boosting agent, the prescribed dose of the primary drug would be ineffective.


How well something works (in real life conditions). See also 'efficacy'.


A rash is an area of irritated or swollen skin, affecting its colour, appearance, or texture. It may be localised in one part of the body or affect all the skin. Rashes are usually caused by inflammation of the skin, which can have many causes, including an allergic reaction to a medicine.


Pain or discomfort in the chest or stomach caused by eating or drinking.


Breakdown product of creatine phosphate in muscle, usually produced at a fairly constant rate by the body (depending on muscle mass). As a blood test, it is an important indicator of the health of the kidneys because it is an easily measured by-product of muscle metabolism that is excreted unchanged by the kidneys.

Evotaz should not be used in combination with HIV protease inhibitors or non-nucleoside reverse transcriptase inhibitors with the exception of rilpivirine. Evotaz should not be used with proton pump inhibitors and if taken with tenofovir, it should not be used with H2 receptor antagonists (e.g. famotidine). In people not taking tenofovir, Evotaz and famotidine should be taken together, with food, or at least ten hours apart.

Indigestion remedies or calcium supplements should be taken at least two hours before or one hour after atazanavir. ‘Buffered’ medicines (drugs that have been prepared so they are released slowly into the body) should be taken at least two hours before or one hour after atazanavir.

Hormonal contraceptives containing ethinyl estradiol 30μg or more should be avoided when taking Evotaz due to the risk of high oestrogen exposure. Alternative forms of contraception should be considered.

Use of the following medicines is also contraindicated with Evotaz:

  • alfuzosin
  • amiodarone
  • astemizole
  • avanafil
  • bepridil
  • bosentan
  • carbamazepine
  • cisapride
  • colchicine
  • dihydroergotamine
  • dronedarone
  • ergometrine
  • ergonovine
  • ergotamine
  • lidocaine (injectable)
  • lovastatin
  • methylergonovine
  • midazolam (oral)
  • phenobarbital
  • phenytoin
  • pimozide
  • quetiapine
  • quinidine
  • rifampicin
  • simvastatin
  • St John’s wort
  • terfenadine
  • ticagrelor
  • triazolam


Evotaz should be avoided if pregnant or planning to conceive owing to a lack of information about its effects in pregnancy.


Evotaz is not approved for use in people under 18.

Further information

Refer to the entry on atazanavir for further information on potential side effects, efficacy and drug resistance.

Next review date