Evotaz (atazanavir + cobicistat) - HIV Drug Information

Image courtesy Bristol-Myers Squibb


Evotaz (atazanavir + cobicistat) is a fixed dose combination antiretroviral drug used in the treatment of HIV. The two components of the drug are individually marketed as Reyataz (atazanavir) and Tybost (cobicistat).

The single-pill co-formulation allows for easy, once-daily dosing, with the cobicistat component effectively "boosting" and sustaining plasma concentration of atazanavir in the body.

Evotaz was approved by the U.S. Food and Drug Administration (FDA) in January 2015 for both new and experienced adult patients with HIV-1 infection.


A film-coated oblong tablet, comprised of 300mg atazanavir and 150mg cobicistat, is pink in color and embossed with the numbers "3641" on one side.


One tablet taken daily with food. Evotaz cannot be used alone but must be taken in combination with one or more accompanying antiretroviral drug(s).


Before starting, patients should be tested to assess their estimated creatinine clearance as Evotaz can potentially impair renal (kidney) function, most often in patients with known or undiagnosed renal dysfunction. When coadministered with Viread (tenofovir)—a drug which may cause renal impairment in some—it is recommended that patients be tested for estimated creatinine clearance, urine glucose, and urine protein.

It is also recommended that treatment-experienced patients, particularly those exposed to HIV protease inhibitors, be provided genetic resistance testing before being prescribed Evotaz. If genotypic testing is not available, Evotaz should be avoided for anyone previously exposed to HIV protease inhibitors.

Common Side Effects

In Phase III human clinical studies, a number of potential drug side effects have been identified when using Evotaz. The most common adverse events, reported in 2% or less of newly treated patients, were:

  • Jaundice (yellowing of the skin and eyes)
  • Ocular icterus (yellowing of the eyes)
  • Rash
  • Nausea

Less common side effects include fatigue, headache, insomnia, vomiting and upper abdominal pain. Kidney stones were also noted in some patients when Evotaz was coadministered with Viread (tenofovir), although the cases were considered mild and did not result in treatment discontinuation.

Drug Contraindications

Evotaz should not be taken with the following drugs or herbal supplements:

  • Anti-anginal medication: Ranexa
  • Anti-arrhythmic medications: Multaq
  • Anti-cholesterol medications: Mevacor, Zocor
  • Anti-gout medications: Uroxatral
  • Anti-hypertension medications: Revatio
  • Antipsychotic medications: Latuda, Orap
  • Cancer medications: Camptosar, Campto
  • Ergot-containing anti-migraine derivatives: DHE 45, Ergotrate, Hydergine, Migranal
  • Rifampin-based anti-tuberculosis medications: Mycobutin, Rifater, Rifamate, Rimactane, Rifadin, Priftin
  • Sedatives: Dormicum, Halcion, Hypam, Hyponvel, Trilam, Versed
  • St. John's Wort

Antiretroviral Drug Interactions

The use of Tybost with following antiretroviral drugs may result either in the loss of therapeutic effect of the accompanying drug or an increase of side effects:

Other Interactions or Considerations

  • Inform your doctor of any known or suspected renal (kidney) condition you may have before starting Evotaz.
  • Inform your doctor of any known or suspected hepatic (liver) condition you may have before starting Evotaz, including hepatitis A, hepatitis B or hepatitis C.
  • Antacids with aluminum or magnesium hydroxide can prevent Evotaz from being properly absorbed. If you are using an over-the-counter antacid (e.g. Rolaids, Tums, Milk of Magnesia), it is suggested that it be taken either two hours before or after a dose of Evotaz.
  • Proton pump inhibitors (e.g., Losec, Prilosec, Prevacid, Nexium, Pariet) can similarly block absorption of Evotaz. It is suggested that they be taken either 12 hours before or after a dose of Evotaz.
  • Erectile dysfunction medication (Viagra, Levitra, Cialis) should be used with caution as Evotaz can boost the level of adverse side effects, including visual disturbances, hypotension, and priapism (painful, sustained erections). It is recommended that Viagra dosage be decreased to no more than 25mg in 48 hours; Levitra dosage be decreased to no more than 2.5mg in 72 hours; and Cialis dosage be decreased to no more than 10mg in 72 hours.
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    • H2-receptor antagonists used to block stomach acid (e.g., Tagamet, Pepcid, Axid, Zantac) can also block absorption of Evotaz. It is suggested that they be taken either with Evotaz or, alternately, 10 hours before or after a dose of Evotaz.
    • During pregnancy, Evotaz should not be prescribed during the second or third trimester, if the pregnant patient is taking either an H2-receptor antagonist or Viread (tenofovir) as there may be a risk of kernicterus (a rare condition that occurs in newborns with severe jaundice).
    • Sources:
    • Bristol-Myers Squibb. "Evotaz (Atazanvir +cobicistat) - FULL PRESCRIBING INFORMATION." New York, New York; accessed February 3, 2015.