Antiretroviral medicines can have many side effects. Some can be very serious, even life-threatening, such as liver failure or inflammation of the pancreas (pancreatitis). Most are not serious but may reduce the quality of your life. Some people who don't have any symptoms of HIV infection may feel worse while taking the medications if they have side effects from the medicines.

Because highly active antiretroviral therapy (HAART) requires the use of 3 or more antiretroviral medicines, some side effects are likely to occur, including:

• Nausea or vomiting.
• Diarrhea.
• Abdominal pain.
• Severe fatigue.
• Muscle aches.
• Rash.
• Fever.

Common long-term side effects of antiretroviral medicines include:

• Redistribution of body fat.
• Increased cholesterol and triglyceride levels.

A serious, potentially life-threatening allergic reaction occurs in a small number of people who take abacavir. A screening test (HLA-B*5701 screening test) is available to help predict who may have a serious reaction to abacavir.¹ The U.S. Department of Health and Human Services (DHHS) recommends that anyone who may receive abacavir should get tested for sensitivity to it first.²

For information on side effects of specific antiretroviral medicines, see:

• Nucleoside/nucleotide reverse transcriptase inhibitors, also called nucleoside analogs, such as tenofovir, emtricitabine, lamivudine, and abacavir.
• Nonnucleoside reverse transcriptase inhibitors (NNRTIs), such as efavirenz, nevirapine, or etravirine.
• Protease inhibitors (PIs), such as atazanavir, darunavir, saquinavir, ritonavir, indinavir, nelfinavir, fosamprenavir, lopinavir/ritonavir, or tipranavir.
• Entry and fusion inhibitors, such as enfuvirtide and maraviroc.
• Integrase inhibitors, such as raltegravir.

Report all side effects to your doctor at your next visit. He or she can adjust your dose or give you other medicines to reduce side effects. Some mild side effects, such as nausea, improve as your body adjusts to the medicine.