Atazanavir

Antiretrovirals

Drug Overview

Atazanavir is a protease inhibitor antiretroviral medication marketed under brand names such as Reyataz and Evotaz.

It is used in combination with other agents for the treatment of HIV-1 infection to suppress viral replication and maintain immune function.

Atazanavir works by inhibiting the HIV-1 protease enzyme, preventing the cleavage of viral polyproteins and resulting in noninfectious viral particles.

Relevant Genes and Their Roles

One key gene affecting atazanavir response is UGT1A1. UGT1A1 encodes the enzyme UDP-glucuronosyltransferase 1A1, which attaches a glucuronic acid molecule to bilirubin and certain drugs to help the body eliminate them.

Genetic variations in UGT1A1 can alter enzyme activity, leading to different metabolizer phenotypes. Reduced activity variants can slow bilirubin clearance and increase the risk of drug-related hyperbilirubinemia (jaundice).

Impact of Genetics on Drug Response

Individuals with reduced or absent UGT1A1 activity experience higher bilirubin levels when taking atazanavir, increasing the risk of jaundice and potential treatment discontinuation, while normal or enhanced activity results in lower risk and standard drug handling; unknown genotypes default to standard dosing with clinical monitoring.

Want to know what your genetics say about how you'll respond to Atazanavir?

A Gene2Rx report reads your own DNA to show how it may affect your response to Atazanavir and your other medications.

Find out today

Or see an example report first

Expected Clinical Effects of Genetic Variation

Ultra-rapid/Rapid Metabolizer

Effect on drug levels: Lower bilirubin levels than average
Clinical consequence: Minimal risk of hyperbilirubinemia
Side effects: No known additional side effects

Normal Metabolizer

Effect on drug levels: Expected (reference) bilirubin levels
Clinical consequence: Very low likelihood of developing jaundice
Side effects: Typical side effect profile; rare mild bilirubin elevations

Intermediate Metabolizer

Effect on drug levels: Moderate increase in bilirubin levels
Clinical consequence: Low likelihood of jaundice-related discontinuation
Side effects: Possible mild jaundice; usually transient and well-tolerated

Poor Metabolizer

Effect on drug levels: Markedly elevated bilirubin levels
Clinical consequence: High likelihood of jaundice and treatment discontinuation
Side effects: Pronounced jaundice (yellowing of eyes/skin); may be severe

Indeterminate/Not Available

Effect on drug levels: Unknown
Clinical consequence: No specific guidance; follow standard dosing
Side effects: Not well characterized

Dosing Guidelines

The following dosing guidelines are based on the available guidelines for atazanavir and UGT1A1 from CPIC.

UGT1A1 Dosing Guideline

Phenotype	Clinical Consequence	Guideline Recommendation
Normal Metabolizer	Reference UGT1A1 activity; very low likelihood of bilirubin-related discontinuation of atazanavir.	There is no need to avoid prescribing of atazanavir based on UGT1A1 genetic test result.
Intermediate Metabolizer	Somewhat decreased UGT1A1 activity; low likelihood of bilirubin-related discontinuation of atazanavir.	There is no need to avoid prescribing of atazanavir based on UGT1A1 genetic test result. Inform the patient that some patients stop atazanavir because of jaundice (yellow eyes and skin), but that this patient’s genotype makes this unlikely
Poor Metabolizer	Markedly decreased UGT1A1 activity; high likelihood of bilirubin-related discontinuation of atazanavir.	Consider an alternative agent particularly where jaundice would be of concern to the patient.
Indeterminate / Not available	Unknown impact	Initiate standard starting dose

Alternative Treatment Options

For patients identified as poor metabolizers (high risk of hyperbilirubinemia), consider alternative antiretroviral agents such as darunavir, lopinavir, or integrase inhibitors. These examples are drawn from CPIC guidance and are provided for informational purposes only.

Sources and References

CPIC – Guideline for atazanavir and UGT1A1

Genes that affect Atazanavir

See the full list of drugs affected by each gene:

UGT1A1

UDP Glucuronosyltransferase Family 1 Member A1

Brand names containing Atazanavir

See how your genetics affect each product Atazanavir shows up in:

Disclaimer: This document is for informational purposes only and is not a substitute for medical advice. Clinical decisions should be made by a qualified healthcare professional.

Interested in learning more about how your genetics may affect your response to medication? Get started with Gene2Rx today.

I'm Interested