Atazanavir – what it does, how to take it, and what to watch for

Atazanavir is an antiretroviral drug used to treat HIV. It belongs to the protease inhibitor class and helps stop the virus from making copies of itself. People use it as part of a combination therapy to lower viral load and protect the immune system.

How it works and practical dosing tips

Atazanavir blocks the HIV protease enzyme so new virus particles can’t mature. It’s usually taken once daily with food to improve absorption. Many regimens include a booster—either low‑dose ritonavir or cobicistat—to raise blood levels and keep the drug working well. Some doctors may prescribe an unboosted dose in select cases, but your exact dose depends on the whole treatment plan and any other drugs you take.

Timing matters. Take atazanavir with a meal and try to keep a consistent schedule. If you miss a dose, follow your clinic’s advice—don’t double up without checking with your provider.

Side effects, tests, and interactions you should know

Common side effects include nausea, stomach upset, and headache. A distinctive effect is increased bilirubin causing yellowing of the skin or eyes (jaundice). That looks alarming but is usually harmless; still, tell your clinician if you notice yellowing. Less common but important risks include liver enzyme changes, kidney stones, and changes in heart rhythm (PR prolongation). Your doctor will ask for baseline liver tests, bilirubin checks, and sometimes an ECG if there are heart concerns.

Drug interactions are a big deal with atazanavir because it relies on liver enzymes (CYP3A) and needs an acidic stomach to absorb properly. Avoid or adjust these common items:

• Proton pump inhibitors (like omeprazole) — they can cut absorption and make atazanavir ineffective.
• H2 blockers and antacids — they change stomach acidity. If you need them, timing rules apply (ask your pharmacist for the right schedule).
• Certain statins (simvastatin, lovastatin) and other meds that use CYP3A — these can cause dangerous drug levels.
• St. John’s wort and rifampin — these lower atazanavir levels and shouldn’t be used together.

Always tell every healthcare provider and your pharmacist that you take atazanavir. They’ll check for interactions and adjust doses or swap medicines when needed.

Quick checklist before you start or change atazanavir:

• Bring a full list of meds and supplements to your clinic visit.
• Expect baseline blood tests (liver, bilirubin, kidney) and follow-up tests.
• Plan to take the drug with food and avoid acid-suppressing drugs unless your doctor gives instructions.
• Report jaundice, dark urine, severe stomach pain, or fainting immediately.

If you have questions about pregnancy, breastfeeding, or long-term side effects, bring them up with your HIV care team. They’ll tailor choices to your situation and keep an eye on safety while helping you stay virally suppressed.