Etravirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that helps to block an enzyme which HIV needs to multiply. The FDA has approved etravirine tablets to be used in combination with other anti-HIV medications, in adults who have failed treatment with other antiretrovirals. Sold under the trade name Intelence (Tibotec Therapeutics, a division of Ortho Biotech Products), etravirine received a priority review by the FDA. Development of etravirine was triggered by the observations of in vitro anti-HIV activity of etravirine against mutant, NNRTI-resistant HIV strains. When used with other active anti-HIV medicines, etravirine reduces the amount of HIV in the blood and increases white blood cells that help fight off other infections. In addition, etravirine may reduce the risk of death or infections that can occur with a weakened immune system. The FDA’s approval of etravirine is based primarily on data from 599 adults who received etravirine in two randomized, double-blind, placebo-controlled trials. After 24 weeks of treatment, more of the patients who received etravirine along with background therapy, experienced reductions in the level of HIV in their blood than did those who received a placebo and background therapy. The most common adverse events reported were rash and nausea. Patients developing a rash while taking etravirine should contact their doctor. To avoid drug interactions, patients starting etravirine treatment should tell their prescribers and pharmacists about all the medications they are taking. In the overall development program for etravirine, rare cases of serious skin reactions such as Stevens-Johnson syndrome and erythema multiforme were reported. Patients taking etravirine may develop infections, including opportunistic infections or other conditions that may develop in patients living with HIV infection. The long-term effects of etravirine are not known, and its safety and effectiveness in children ages 16 years and younger has not been studied. Etravirine also has not been studied in pregnant women. Women who are taking HIV medications when they become pregnant are advised to consult their physician or other health care professional about use of etravirine during pregnancy and about registering with the Antiviral Pregnancy Registry.