Yes, Lexapro (escitalopram), can treat panic disorder. Although Lexapro is only FDA-approved for the treatment of major depressive disorder and generalized anxiety disorder, Lexapro can also treat panic disorder. All of the major anxiety disorder except for specific phobia can be treated with Lexapro.
Lexapro is a Selective Serotonin Reuptake Inhibitor (SSRI), which blocks the reuptake of serotonin and increases serotonin in neuronal synapses. This increase in serotonin is how SSRIs such as Lexapro relieve anxiety symptoms in someone with panic disorder. Lexapro cools down the hyperactive anxiety circuits, of which the amygdala is a major component.
The advantage of Lexapro over other SSRIs for panic disorder is that it has fewer side effects. Additionally, Lexapro has fewer drug-drug interactions when combining with other medications. Lexapro is the active S-enantiomer of the racemic mixture Celexa (citalopram). In other words, Celexa contains both enantiomers of the molecule, which are mirror-images of each other, and Lexapro only has one enantiomer, the active S-enantiomer. Consequently, Lexapro is more potent than Celexa, requiring lower doses for effectiveness in anxiety and depression, and this may be associated with less side effects, given the lower dosage.
Lexapro went off patent in 2012, so it is available in generic form. As such, it is priced lower than brand name Lexapro. In addition, generic Lexapro is now priced similarly to generic Celexa. What this means is that there is no longer a big price differential between Lexapro and Celexa, as Lexapro recently went off patent, making cheaper generics available.
In summary, Lexapro can treat panic disorder. Lexapro is also now available as a generic, so it is comparable in price to generic Celexa. In general, Lexapro is associated with fewer side effects and less drug-drug interactions when compared to the other SSRIs.