Lexapro is the brand name for escitalopram oxalate. Escitalopram is an antidepressant, one of a class of drugs called selective serotonin reuptake inhibitors (SSRIs.) Other SSRIs include citalopram (Celexa,) fluoxetine (Prozac, Prozac Weekly,) paroxetine (Paxil, Paxil Weekly) and sertraline (Zoloft.)
SSRIs are thought to work by blocking the reabsorption (reuptake) of a particular neurotransmitter (serotonin) by certain neurons in the brain, thus increasing the available pool of serotonin to stimulate other neurons to fire. This seems to elevate mood.
What Is In the Pill?
The active ingredient in Lexapro is escitalpram oxalate or S-(+)-1-[3-(dimethyl-amino)propyl]-1-(p-fluorophenyl)-5-phthalancarbonitrile oxalate. The molecular formula for Escitalpram oxalate is C20H21FN20 . C2H2O4, and its molecular weight is 414.40 g/mol. It is a fine powder that is white to slightly yellow.
Three different strengths of the active ingredient within Lexapro tablets are marketed: 5 mg, 10 mg and 20 mg.
Lexapro tablets also contain the following excipients, or inactive compounds, used in the manufacturing of the tablet: croscarmellose sodium, microcrystalline cellulose/colloidal silicon dioxide, magnesium stearate and talc. With only a few inactive ingredients, this is a very simple tablet. The tablets are film-coated with hypromellose, titanium dioxide and polyethylene glycol.
The oral solution of Lexapro, which has 1 mg/mL of active escitalopram oxalate, also includes purified water, sorbitol, citric acid, malic acid, sodium citrate, glycerin, propylene glycol, methylparaben, propylparaben and natural peppermint flavor.
You should not take Lexapro if you are allergic to any of the ingredients.
What Should I Know?
Lexapro is available only by prescription and is only approved for adults and adolescents 12 to 17 years of age. It is not approved for children.
In adolescents, especially during the first few weeks of therapy, Lexapro and all SSRI therapies may increase the risk of suicidal thoughts and suicide. Bipolar disorder or a family history of bipolar disorder increases this risk. Suicidal thoughts or attempts should be reported to your physician immediately.
This effect was not seen in adults over 24 years of age, and a statistical decrease in suicidal thoughts was seen almost immediately in adults over 65 years of age.
Cool Science Stuff
Lexapro or escitalopram is a new product similar to Forest Lab's earlier SSRI drug citalopram hydrobromide (Celexa.)
Citalopram HBr is a racemic mixture of two enantiomers of a bicyclic phthalane derivative. The scientific name is (±)-1-(3-dimethylaminopropyl)-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5-carbonitrile, HBr. A "racemic mixture" means that Celexa is a mixture of two subtly different structural compounds that have the same formula. All the atoms are the same, but the structures of the two molecules are slightly different.
Lexapro, however, is only the S-enantiomer from the racemic mixture Celexa. The S-enantiomer in Lexapro is at least 100 times more active than the R-enantiomer.
Thus, a drug that contains only the very active enantiomer (instead of a mixture of both the very active and much less active forms of the drug) should use a lower dosage to achieve the same effects and thus reduce side effects.
