What is Atazanavir (Reyataz) ?
Atazanavir is an HIV Protease Inhibitor (PI) drug that is active against both mutant and wild-type HIV-1. It is used in the treatment of an HIV-1 infection in combination with other antiretroviral drugs; this usually includes a low-dose of ritonavir. The drug is not active against HIV-2. It works by inhibiting HIV protease function, thereby potently blocking the formation of mature virions.
Atazanavir is indicated for the treatment of an HIV-1 infection, but it is also used in an off-label manner for post-exposure prophylaxis for HIV following occupational exposure; in either case, it should be used in conjunction with other drugs. The drug may be used in adults, children, and infants three months and older weighing 5 kg or more. Atazanavir oral capsules must be swallowed whole and should not be opened. This drug also comes in the form of an oral powder. Dosage instructions and considerations are given in further detail in the package insert.
Atazanavir HIV drug requires a dosage reduction in patients with hepatic dysfunction, and the drug should not be used in patients with severe hepatic impairment. Patients with a Hepatitis B virus (HBV) or Hepatitis C virus (HCV) co-infection or preexisting liver dysfunction should be monitored as outlined 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 a hypersensitivity to the drug, in patients with severe liver dysfunction (Child-Pugh Class C), and when combined with ritonavir for patients with moderate liver impairment. This medication is contraindicated for use with certain medications listed in the package insert.
Atazanavir Side Effects
Atazanavir can cause serious liver and heart rhythm-related side effects.
Other potential adverse effects include:
- renal calculi,
- fat redistribution.
A complete list of potential adverse effects is provided in the package insert.
Atazanavir should be used with caution in patients with a cardiac AV block, as it may prolong the PR interval in some patients. Capsules should be used with caution in hemophiliacs due to the increased bleeding risk.
All patients who test positive for HIV should be screened for comorbid HBV and HCV infection. Co-infected patients should be started on an antiretroviral treatment regimen targeting co-infected viruses, regardless of CD4 counts or viral loads. Current HIV treatment guidelines outline drug regimens and prescribing considerations.
Atazanavir is associated with a large number of drug-drug interactions, so prescribers should familiarize themselves with the list provided in the product’s package insert.
Pregnancy & Lactation
When indicated, highly active retroviral combination treatment should be used in all pregnant women, regardless of viral load and CD4 count. Data from the Antiretroviral Pregnancy Registry does not associate atazanavir with any increase in the risk of overall major birth defects occurring compared to the baseline.
Atazanavir is excreted in the breast milk. The CDC recommends that all HIV positive women, treated or untreated, avoid breastfeeding to prevent vertical transmission of the virus.
There is no treatment that is specific for an overdose of atazanavir. Patients should be closely monitored and provided with supportive care. The drug is most likely not removed by hemodialysis.
Alternative Brand Names
Atazanavir is also available under the brand name Reyataz.