Darunavir — what you need to know

If you or someone you care for is on HIV treatment, darunavir is one of the commonly used protease inhibitors. It works by stopping the HIV protease enzyme, which helps the virus make new infectious copies. That lowers viral load and protects the immune system when taken correctly with other antiretrovirals.

Darunavir is almost always used with a booster—either ritonavir or cobicistat. The booster raises darunavir levels so one dose works better. Don’t stop or change the booster without talking to your provider; doing so can make the treatment fail.

Practical dosing and adherence tips

Typical dosing is once daily when the virus is susceptible and combined with other appropriate drugs. For some resistant cases, doctors use twice-daily dosing. Exact dose depends on your treatment history and lab results. Always follow the prescription on your bottle and ask your clinic if you’re unsure.

Take darunavir with food—this improves absorption. Use a simple routine: pair the dose with a regular meal or an evening activity. If you miss a dose, take it as soon as you remember unless it's almost time for the next dose; then skip the missed dose. Never double-dose to catch up.

Side effects, interactions, and what to watch for

Common side effects include nausea, diarrhea, headache, and sometimes rash. Darunavir can raise liver enzymes and blood lipids. If you have liver disease or hepatitis, your doctor will monitor you more closely. Stop and call your provider right away if you develop a severe rash, yellowing of the skin, dark urine, or persistent stomach pain.

Darunavir interacts with many medicines because it affects the CYP3A enzyme system. That includes some heart drugs, statins, sedatives, and herbal supplements like St. John’s wort. Before starting any new drug, prescription or over-the-counter, check with your prescriber or pharmacist.

Routine monitoring usually includes viral load and CD4 counts to check effectiveness, plus liver tests and lipid panels. These tests tell your team whether the regimen is working and whether side effects need managing.

Thinking of pregnancy? Talk to your provider. Some antiretroviral regimens are preferred in pregnancy; clinicians balance benefits and risks and may adjust drugs based on the latest guidelines.

If you’re buying medication online, use only licensed pharmacies that require a prescription. Avoid sites that offer darunavir without asking for a prescription or that have suspiciously low prices. Counterfeit or wrong drugs can be dangerous and may lead to resistance.

Final practical note: keep darunavir in its original container at room temperature, away from moisture. Keep a list of all your medicines and bring it to appointments. If you notice side effects or changes in how you feel, contact your clinic—early action keeps treatment on track.