What is Atazanavir (Reyataz)?
Atazanavir is an HIV Protease Inhibitor (PI) drug, which is active against both types of HIV-1 (mutant and wild-type). It is used in combination with a low-dose antiretroviral drug (usually ritonavic) for the treatment of HIV-1 infection. This medication inhibits the HIV protease function which blocks the formation of mature virions. The drug does not treat HIV-2.
Atazanavir is indicated for the treatment of HIV-1 infection, or off-label as post-exposure prophylaxis for HIV following occupational exposure, as part of a combination drug regimen. It may be used in adults, children, and infants three months and older weighing 5 kg or more. The drug oral capsules must be swallowed whole and should not be opened. An oral powder is also available. Dosing instructions and considerations are given in detail in the package insert.
Atazanavir requires dose reduction in patients with hepatic dysfunction, and the drug should not be used in severe hepatic impairment. Patients with Hepatitis B virus (HBV) or Hepatitis C virus (HCV) co-infection or pre-existing liver dysfunction should be monitored as described in the package insert. No dosage adjustments are necessary for patients with renal impairment, except for those receiving hemodialysis.
Atazanavir is contraindicated in patients with severe liver dysfunction (Child-Pugh Class C), or in those with hypersensitivity to the drug. It is also contraindicated in patients with moderate liver impairment with it is combined with ritonavir. As described in the package insert, Atazanavir is contraindicated for use with some medications.
Atazanavir Side Effects
This medication can cause serious liver and heart rhythm side effects.
Other potential adverse effects include:
- renal calculi,
- fat redistribution.
A complete list of potential adverse effects is provided in the package insert.
In the presence of cardiac AV block, Atazanavir should be used with caution because it may prolong the PR interval in some patients. It should also be used in caution in those with hemophilia as it poses an increased risk of bleeding.
For those who test positive for HIV infection, they should also be screened for HCV infection and comorbid HBV. Regardless of viral loads or CD4 counts, patients who are considered co-infected should be started on an antiretroviral regimen targeting co-infected viruses.
Atazanavir is associated with a large number of drug-drug interactions and contraindications and prescribers should familiarize themselves with the list provided in the package insert.
Pregnancy & Lactation
Pregnant women who are HIV positive should use highly active retroviral combination treatment, regardless of viral load and CD4 count. Research done by the Antiretroviral Pregnancy Registry does not show any risk of an increase in major birth defects compared to baseline numbers. The CDC recommends that all HIV positive women, treated or untreated, avoid breastfeeding since Atazanavir is excreted in breast milk.
There is no treatment that is specific for Atazanavir overdose. Patients should be closely monitored and provided with supportive care. The drug is probably not removed by hemodialysis.
Alternative Brand Names
Atazanavir can also be purchased under the brand name, Reyataz.