Lexapro is a selective serotonin reuptake inhibitor that is used to treat depression and anxiety disorder. Lexapro is a brand name of the drug escitalopram, an antidepressant that belongs to the class of medications called selective serotonin reuptake inhibitor. This drug is used in treating anxiety and depressions as well as other mental or mood disorders like panic disorders and obsessive-compulsive disorder. Lexapro is available as an oral solution or in tablet form. The tablets are film-coated and the round ones contain escitalopram oxalate of varied strength equivalents of 5, 10 and 20 mg. The oral solution, on the other hand, contains escitalopram oxalate of strength equivalent 1 mg/mL. Lexapro works by initiating the blockage of reuptake or reabsorption of neurotransmitter (serotonin) in the brain. The drug takes weeks to initiate an effect.