Posted by Adam on November 26, 2001, at 9:26:34
In reply to Re: Escitalopram » nightlight, posted by Cam W. on November 25, 2001, at 19:15:02
The same approach has been taken with fluoxetine: Rather than sell a racemite, sell the active (or most active) enantiomer.
I'm not sure about citalopram, but in the case of fluoxetine, it is thought that its stereoisomers are not only different for 5-HT-reuptake inhibition, they may be different for some other properties (receptor agonism, perhaps). Most interestingly, this refinement of the drug is thus thought to reduce some side effects, and that is part of the patent-extension and marketing angle. The irony is, some of these alleged "side effects" have gotten Eli Lily sued, and Lily did their damnedest before to defend themselves against liability by claiming they didn't exist.
> Nightlight - Escitalopram is the "S" isomer of citalopram (Celexa) which is the more active isomer of this antidepressant (ie. the isomer that has much more antidepressant activity). The citalopram isomers (R and S) are mirror images of each other, and Celexa is a mixture of the R and S isomers. Theoretically, escitalopram will be a more potent version of Celexa).
>
> Since Forest will soon lose it's exclusivity of citalopram (ie. generic companies will be able to make and sell their own version), this is a way of extending the patent of their drug.
>
> - Cam
poster:Adam
thread:85011
URL: http://www.dr-bob.org/babble/20011123/msgs/85187.html