Atazanavir: What it does, common side effects, and drug interactions

Atazanavir (brand name Reyataz) is an HIV protease inhibitor used with other antiretrovirals to keep viral load low. It’s usually given once daily and often boosted with ritonavir or cobicistat so levels stay high enough to work. If you or someone you care for is on atazanavir, this page gives practical, straightforward facts that help you use it safely.

How to take atazanavir

Take atazanavir with food — food increases absorption. Many people take it once a day at the same time to build a routine. If your doctor prescribes a booster (ritonavir or cobicistat), follow that exact schedule. Don’t stop or skip doses without talking to your clinician; missing doses can let the virus rebound and might cause resistance.

Want a quick rule? Always check with your prescriber before combining atazanavir with other medicines, vitamins, or OTC products. That includes herbal remedies and supplements — some look harmless but can alter drug levels.

Side effects and what to watch for

The most noticeable side effect is increased bilirubin. That can cause yellowing of the skin or eyes (jaundice), but it’s usually not a sign of liver damage. Other common issues: nausea, diarrhea, headache, and rash. Rarely, atazanavir can affect heart rhythm or kidney stones. Your clinic will likely check bilirubin and liver tests before and during treatment.

If you see dark urine, severe stomach pain, new yellowing, or unusual bleeding, contact your healthcare provider right away. Also tell your provider if you have a history of heart conduction problems or kidney stones — dosing or monitoring may change.

Pregnancy and breastfeeding require special discussion. The goal in pregnancy is a suppressed viral load to protect the baby. Your HIV specialist will weigh risks and pick the safest plan.

Interactions are a big deal with atazanavir. It needs an acidic stomach to be absorbed. That means acid-reducing drugs — especially proton pump inhibitors (PPIs) like omeprazole — can lower atazanavir levels and reduce effectiveness. H2 blockers and antacids also interfere. The safest move: avoid PPIs unless your doctor gives clear instructions. If antacids are needed, ask when to space them around your atazanavir dose.

Atazanavir interacts with many other medicines (statins, some heart rhythm drugs, rifampin and certain antibiotics, some sedatives). Always show your clinic a current list of medications and ask a pharmacist if you start something new.

Alternatives exist — other protease inhibitors (like darunavir) or different drug classes (integrase inhibitors) may be better for some people. If side effects or interactions are a problem, discuss switching options with your HIV provider.

If you want help reading a prescription label or checking a possible interaction, your pharmacist can run a quick check. Keep regular follow-ups, get blood tests as requested, and ask questions — that’s how you stay both safe and well controlled on therapy.