Posted by moxy1000 on September 1, 2002, at 14:14:07
In reply to lexapro (P.I.) dose dependant adverse events, posted by pharmrep on September 1, 2002, at 0:00:38
Seems there is a lot of talk about generic Celexa again, and I think there a couple of things to think about. One, no Celexa generic will be available in the U.S. until approx mid 2005. I think Celexa's patent/exclusivity runs through the end of 2004 and they just received another 6 month patent extension for some studies they did in pediatrics. (I assume generic Celexa/Cipralex formulations are available now in Europe?) Second, Lexapro will be priced Cheaper then Celexa, and thus all other SSRI's. Therefore, if you think about the fact that the folks that run HMOs and formularies usually choose the least expensive agents to make available to their customers, it's probably safe to assume that Lexapro will replace Celexa/or other AD's on a lot of formularies. (Another thing to think about is that very soon the company that makes both drugs will no longer be making much $ on Celexa anymore.) In the case of Lexapro being introduced to the states, one thing is clear - this was Not an invention/product release that came about due to a "patent emergency."
So why is Lexapro being released here? It has been said that it is "basically the same as Celexa." Why would a company introduce a drug that is effectively the same as a drug they have three years left to make money off of? Yes, the two drugs are the same in regards to their mechanism of action - both are SSRI's. But saying they are the same is effectively like saying Lexapro is the same as Prozac. It's like saying an apple is the same as an orange. They are two different molecules, thus having different effects on the body. A couple of things to consider - in vitro data shows Lexapro as being 100 times more potent then Celexa for the inhibition of serotonin reuptake - this means simply that Lexapro will increase serotonin levels at a much higher rate then Celexa. (Does anyone want to hear a disertation about receptor binding of Celexa, the R-enantiomer, and the S-enantiomer? I didn't think so - but I can give the sources and further data if necessary.) However, That is one important difference. The second difference is that in every study I've seen to date - authored by many different physicians - the onset of Lexapro in improving depression occured in 1-2 weeks. This is also a difference, as Celexa and all the other SSRI's claim onset at 4-6 weeks. Also, Lexapro's high life is a bit shorter, and protein binding is less. The side effect profile is cleaner, and Lexapro has the less potential for drug interactions then even Celexa does. I wont go into detail here about the significance of those things, however, it furthers the argument that Lexapro is NOT the same as Celexa.
How does one pose an argument based on this: The authors of a study give their findings on Lexapro. The data looks encouraging. The only argument against the data is that the authors cannot be trusted because the studies were sponsored by a drug company. Funny, when Prozac was introduced, all of their studies were sponsored by the parent drug company, yet physicians through "caution to the wind" and began prescribing it anyway. Thankfully, this brought about a revolution in AD treatment and the patients that finally ditched their irritating Tricyclic meds gave a round of applause for a better tolerated medication.
I still don't think anyone has explained successfully why the company that makes celexa would abandon it's marketing and sampling of Celexa in the U.S. when the patent is good for three more years. And why they would introduce the "same drug under a different name" as some claim requires an explanation also. There seems to be only one school of thought that makes sense - they looked at both Celexa and Lexapro, examined all the relevant studies for both agents, and decided to introduce a superior agent, rather then sit on Celexa until it's patent ran out in a few years. (Can you imagine the backlash against the company if they said, "Yeah, we knew about Lexapro back in 2002, but gee, we had Celexa and were making money hand over fist, so we just tucked Lexapro away for a rainy day." People would be furious if they then tried to market Lexapro as being superior.) Heck, they probably even did some research and believe in the long haul they'll make even more money on Lexapro, if we stick with the "drug companies are fundamentally concerned only with their bottom line and really don't care about patients" approach.What other feasible explanation could there be for Lexapro's release in the U.S.? I'd love to hear any feedback on this...as I have been noodling this concept for several weeks and have been unable to arrive at any other conclusion. If there's another explanation that factually makes sense, I'd probably change my mind completely on Lexapro. But so far, the only argument against Lexapro that I've heard is one based on the authors of every study being dishonest. Is it a conspiracy?
Sorry about the long post. I was banned for a week (apologies Dr. Dave) so I had a lot of thoughts to share.
poster:moxy1000
thread:109458
URL: http://www.dr-bob.org/babble/20020829/msgs/118428.html