exclusive to patients of African origin. Among the more severe side effects patients may experience are a hepatotoxicity or a lactic acidosis. Mechanism of action Emtricitabine is an analogue of cytidine. The drug works by inhibiting reverse transcriptase, the enzyme that copies HIV RNA into new viral DNA. By interfering with this process, which is central to the replication of HIV, emtricitabine can help to lower the amount of HIV, or "viral load", in a patient's body and can indirectly increase the number of immune system cells (namely T cells/CD4+ T-cells). Both of these changes are associated with healthier immune systems and decreased likelihood of serious illness. History Emtricitabine was discovered by Dennis C. Liotta, Raymond F. Schinazi, and Woo-Baeg Choi of Emory University and licensed to Triangle Pharmaceuticals by Emory in 1996. Triangle Pharmaceuticals was acquired in 2003 by Gilead Sciences, which completed development and now markets the product with the brand name Emtriva. It was approved by the FDA July 2, 2003. It is very similar to lamivudine (3TC) and cross-resistance between the two is near-universal. References External links Gilead Sciences Hepatotoxins Nucleoside analog reverse transcriptase inhibitors Oxathiolanes Organofluorides Pyrimidones World Health Organization essential medicines Hydroxymethyl compounds