Escitalopram is a selective serotonin reuptake inhibitor (SSRI) that is usually used in the treatment of depression. It is usually preferred over other SSRIs due to its relative lack of drug interactions (it is the only one, aside from citalopram, to not interact with the metabolism of drugs in the liver), superior efficacy and relative lack of side effects.[1] It is one of only two SSRIs that are known to cause QT interval prolongation.