Posted by Patson on August 19, 2002, at 23:04:43
In reply to Re: Lexapro, posted by christophrejmc on February 18, 2002, at 22:39:32
> A lot of people think this is just a gimmick to extend the patent of Celexa.
>I don't think Celexa's patent runs out for at least another year due to an extension for pediatric studies. Further, it takes up to 18 months for a generic to be approved as "equal" by the FDA. That means generic citalopram won't be available until... 2005?
> Celexa (citalopram) contains the R- and S- enantiomers (just means it contains equal amounts of molecules that have different atomic ordering -- called a racemic mixture). Lexapro (escitalopram) only contains the S- enantiomer (the R- (right) enantiomer is thought to have no anti-depressant effect and may be responsible for some of the side-effects). They probably knew about this all along, but decided to release Celexa just so they could later introduce a new-and-improved version to capture market share they would've lost from Celexa going generic. (Incidentally, S-, as in S-citalopram, stands for sinister (meaning left) -- irony?)
>
> -Christophre
>
> Hmm.. my knowledge of chemistry (especially stereochemistry) is pitiful, someone correct me if I've made a mistake.
>
>
poster:Patson
thread:94498
URL: http://www.dr-bob.org/babble/20020814/msgs/117029.html