Escitalopram (Lexapro, Lexaprin, Cipralex, Sipralexa, Entact and Seroplex) is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. It is approved for the treatment of major depressive disorder and generalized anxiety disorder; other indications include social anxiety disorder, panic disorder and obsessive-compulsive disorder. Escitalopram is the S-stereoisomer (enantiomer) of the earlier Lundbeck drug citalopram (Celexa), hence the name escitalopram. Escitalopram is noted for its high selectivity of serotonin reuptake inhibition and, as a result has fewer side effects not related to its serotonergic activity. The drug is marketed in the United States under the name Lexapro by Forest Laboratories and elsewhere under various brand names by Lundbeck.

Escitalopram

Escitalopram was developed in a close cooperation between Lundbeck and Forest Laboratories. Its development was initiated in the summer of 1997, and the resulting new drug application was submitted to the FDA in March 2001. The short time (3.5 years) it took to develop escitalopram can be attributed to the previous extensive experience of Lundbeck and Forest with citalopram, which has similar pharmacology. The FDA issued the approval of escitalopram for major depression in August 2002 and for generalized anxiety disorder in December 2003. Escitalopram can be considered an example of "lifecycle management" - the strategy pharmaceutical companies use in order to extend the lifetime of a drug, in this case of the citalopram franchise. Escitalopram is an enantiomer of citalopram, used for the same indication, and for that reason it required less investment and less time to develop. Two years after escitalopram's launch, when the patent on citalopram expired, the escitalopram sales successfully made up for the loss. On May 23, 2006, the FDA approved a generic version of escitalopram by Teva. However, on July 14th, 2006 the US District Court of Delaware decided in favor of Lundbeck regarding the patent infringement dispute and ruled the patent on escitalopram valid.

Despite the drug's similarity, preclinical as well as various clinical studies (including double-blinded studies—considered the gold standard of clinical evidence) have shown differentiated effects of citalopram and escitalopram as well as a clinical superiority compared to a variety of other SSRIs, such as paroxetine especially in severely depressed patients and sertraline. Compared to newer serotonin-norepinephrine reuptake inhibitors such as venlafaxine and duloxetine escitalopram was shown to be at least as effective.