Escitalopram is an antidepressant drug belonging to the selective serotonin reuptake inhibitor (SSRI) class. Actually, the escitalopram is nothing but the S enantiomer of citalopram (in fact, we read es-citalopram).
(R, S) - Citalopram - Chemical Structure
In the literature, studies are reported which state that the activity of citalopram is to be attributed exclusively to the S enantiomer, while the R enantiomer weakens only the action of the other isomer competing with it for the link with the SERT (the transporter responsible for serotonin reuptake). Furthermore, the R enantiomer is eliminated more slowly than the S enantiomer, therefore - when the drug is administered in the form of a racemate (citalopram) - the inactive R isomer predominates, thus preventing the binding of the active S isomer. All these reasons are an incentive for using the enantiomerically pure S-citalopram form, ie for the use of escitalopram.
The escitalopram has the same identical affinity and selectivity as citalopram towards the transporter responsible for the reuptake of serotonin within the presynaptic termination. Therefore, the mechanism of action and pharmacokinetics of escitalopram are similar to those of citalopram. The same goes for side effects and contraindications.
However, unlike citalopram, escitalopram - in addition to being used for the treatment of major depression and anxiety disorders with panic attacks, with or without agoraphobia - can also be used to treat:
- Social anxiety disorder;
- Generalized anxiety disorder;
- Obsessive-compulsive disorder.
