Efavirenz, emtricitabine, and tenofovir combination is used alone or with other anti-HIV medicines to treat human immunodeficiency virus (HIV) infection. HIV is the virus that causes acquired immune deficiency syndrome (AIDS). Efavirenz comes as a capsule and as a tablet to take by mouth. Take once a day with plenty of water on an empty stomach (at least 1 hour before or 2 hours after a meal). Taking efavirenz at bedtime may make certain side effects less bothersome. Take efavirenz at around the same time every day. Take efavirenz exactly as directed. Do not take more or less of it or take it more often than. Find patient medical information for Efavirenz (Sustiva) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Efavirenz (EFV), sold under the brand names Sustiva among others, is an antiretroviral medication used to treat and prevent HIV/AIDS. [1] It is generally recommended for use with other antiretrovirals. [1] Efavirenz works with other medication to treat HIV. HIV slowly weakens your immune system. You can take this capsule by mouth as directed. Efavirenz: side effects, dosage, interactions, FAQs, reviews. Used for: HIV-1 infection, nonoccupational exposure, occupational exposure Efavirenz is a drug prescribed for the treatment of the human immunodeficiency virus (HIV). Review side effects, dosage, drug interactions, warnings and precautions, and pregnancy safety information. Efavirenz is an FDA-approved antiretroviral medication introduced in 1998 (and approved for use in the UE in 1999) that has played a pivotal role in the treatment and prevention of HIV. As a member of the non-nucleoside reverse transcriptase inhibitor (NNRTI) class, efavirenz is an integral component of antiretroviral therapy (ART) regimens. By selectively inhibiting the reverse transcriptase. Drug information about efavirenz for patients: important things to know, what to tell your doctor before using, how to use, side effects, and more. Efavirenz is a non-nucleoside reverse transcriptase inhibitor indicated in combination with other antiretroviral agents for the treatment of human immunodeficiency virus type 1 infection in adults and in pediatric patients at least 3 months old and weighing at least 3.5 kg. (1).