Pharmacology · HIV protease inhibitors (PIs)
Atazanavir !
A once-daily PI. It causes benign jaundice from indirect bilirubin and needs stomach acid, so antacids and acid suppressants affect it.
Updated 2026-11-01
Also called: ATV
The figure shows atazanavir in the active site of wild-type HIV-1 protease.
Mechanism of action
It fills the HIV protease active site and prevents virus maturation. It also inhibits human UGT1A1, the enzyme that conjugates bilirubin, so indirect bilirubin rises without liver damage.
- It binds the HIV protease active site
- Viral polyproteins stay uncut
- Virions come out immature
Pharmacokinetics
- Absorption
- Taken with food; its solubility falls as gastric pH rises
- Metabolism
- Liver, by CYP3A; inhibits CYP3A and UGT1A1
Indications
- HIV-1 infection, combined with other antiretrovirals, usually boosted with ritonavir HIV infection and AIDS →
Adverse effects
Common
- Indirect hyperbilirubinaemia with jaundice or yellow eyes
- Nausea
- Rash
Contraindications
- Drugs highly dependent on CYP3A or UGT1A1 with serious risk if raised
- Strong inducers such as rifampicin or St John's wort
Key interactions
- Proton pump inhibitors, H2 blockers and antacids
- Lower atazanavir absorption; avoided or separated according to the label
- Tenofovir disoproxil
- Lowers atazanavir: boosted atazanavir is used
- Other PR-prolonging drugs
- Higher risk of AV block
What is monitored
- Bilirubin (indirect) and liver tests
- ECG if there is conduction disease
- Symptoms of kidney stones or gallstones
- Lipids
Administration and safety
- By mouth, with food
- Check the timing of antacids and acid suppressants relative to atazanavir
- Keep a full list of medicines and herbal products and review it with pharmacy before any new drug
Nursing care
- Explain that yellow eyes or skin are usually benign but must be reported and transaminases checked
- Encourage good hydration and teach to recognise renal colic pain
- Ask about heartburn medicines
Pregnancy and breastfeeding
Antiretroviral treatment in pregnancy protects the mother and lowers HIV transmission to the baby; the treating team chooses the regimen.
Test yourself
Think of the answer, then tap the question to see it.
Why does atazanavir cause jaundice with normal transaminases?
It inhibits UGT1A1, which conjugates bilirubin: indirect bilirubin rises without liver injury.
Why do proton pump inhibitors interact with atazanavir?
Atazanavir dissolves less when gastric pH rises, so less is absorbed.
Which kidney complication is linked to atazanavir?
Nephrolithiasis (kidney stones).
Related drugs
Related conditions
← Back to the class: HIV protease inhibitors (PIs)
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - ATAZANAVIR capsule (DailyMed (U.S. National Library of Medicine), 2025); Atazanavir: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); eEML - Electronic Essential Medicines List (World Health Organization, 2025).
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Representative model, for educational purposes only.