![[dr. bob]](/dr-bob-sm.gif)
Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 246 to 270 of 8406. Go back in thread:
Posted by Dinah on September 1, 2002, at 18:40:44
In reply to Re: bad logic from Dr. Dave » dr. dave, posted by pharmrep on September 1, 2002, at 18:30:40
> why dont you try it instead of being Dr. Theory all the time. Afterall, you are in Europe and have had the opportunity where we in the US have not.
Dinah here.
Pharmrep, please don't post anything that could lead others to feel accused or put down.
I'd like to keep this discussion about ideas rather than about fellow posters.
Here is a link to Dr. Bob's civility guidelines:
http://www.dr-bob.org/babble/faq.html#civil
This is a volatile thread with feelings running high on all sides. Please remember to be careful how you phrase your posts (and your subject headings).
I appreciate your cooperation while Dr. Bob is away.
Dinah
Posted by dr. dave on September 1, 2002, at 18:47:56
In reply to Re: bad logic from Dr. Dave » dr. dave, posted by pharmrep on September 1, 2002, at 18:30:40
Just a couple of things. Firstly, I have a duty to be 'Dr Theory'. I need to know and understand research on new drugs and to be able to make out what the results mean. I would expect my doctor to do this. I would want my doctor to think for him- or herself, and I would not appreciate it if they tried new drugs out on me just because they were new, if they weren't convinced they were any better than the established drugs.
Secondly, I deal with the realities of prescribing antidepressants to people every working day, and have done for years. I would like to ask you to please refrain from sarcasm directed towards me - please can we stick to discussing the facts.
> You site the same studies that have opposite conclusions from what you are saying. The Sanchez study showed that s-citalopram is acutally being inhibited from r-citalopram in the microdialysis study. that 2mg of s-cit/Lexapro was more effective than 4mg of Celexa (2mg of s-cit + 2mg of r-cit). Therefore indicating that the r-cit does not help the racemic mixture at all.....and you said "s-citalopram is all that they realistically had." Did you know that the technology used to separate the isomers is so new that the scientists that invented it won the Nobel prize for chemistry for 2001? Lundbeck and Forest are not sitting and waiting, but being proactive and trying to develop better medicine....why dont you try it instead of being Dr. Theory all the time. Afterall, you are in Europe and have had the opportunity where we in the US have not.
Posted by pharmrep on September 1, 2002, at 18:49:08
In reply to Re: Please be civil » pharmrep, posted by Dinah on September 1, 2002, at 18:40:44
> > why dont you try it instead of being Dr. Theory all the time. Afterall, you are in Europe and have had the opportunity where we in the US have not.
>
> Dinah here.
>
> Pharmrep, please don't post anything that could lead others to feel accused or put down.
>
> I'd like to keep this discussion about ideas rather than about fellow posters.
>
> Here is a link to Dr. Bob's civility guidelines:
>
> http://www.dr-bob.org/babble/faq.html#civil
>
> This is a volatile thread with feelings running high on all sides. Please remember to be careful how you phrase your posts (and your subject headings).
>
> I appreciate your cooperation while Dr. Bob is away.
>
> Dinah*** My bad. I guess I am getting steamed. I have been in PB awhile now...and I was upfront on my "Pharmrep" to be open with everybody. I have the same right as anyone else to be here, and I take extra precautions to be sensitive and not "saleslike" in my posts, and site studies as often as I can. I have received mostly fair posts from others, and although topics get heated, I know we are entitled to our opinions (hopefully that can be based on facts and studies). So I agree...lets turn it down a notch and try to be a little more conscious of our posts and keep it fact-based.
Posted by LostBoyinNC1 on September 1, 2002, at 18:52:08
In reply to Re: Lexapro side-effects » dr dave, posted by pharmrep on August 31, 2002, at 22:13:49
.
>Stop trying to find a reason why you disagree >with the studies...and be a little more >objective, or better yet...let the folks >here in the US have the chance to decide for >themselves if they want to try Lexapro...since >you arent willing to and have had the chance for >some time now.How about if you try to be more objective pharmrep, instead of telling other depressives who have personally "been there, done that" what the real deal is with SSRIs? You can improve your objectivity by simply publicly admitting that:
1) Lexapro is just another "me too" serotonin SSRI. This is a hard fact, anyone who reads about it can see this for themselves. Its been proven that one SSRI is as good as another SSRI. No SSRI is any better than another.
2) By admitting to yourself and others on here that you are a Forest Labs drug salesman whose job is to sell Lexapro. Its difficult, if not impossible for you to be truly objective because of who you are. You have a conflict of interest. Do you know what a conflict of interest is, pharmrep? Because youve got one.
You have a lot of gaul telling people on here, sick people who have serious medical problems that they should "be objective" when you yourself are about as biased as a person can be. Youre a Lexapro drug salesman for Forest Labs.
LostBoyinNC
Posted by Simcha on September 1, 2002, at 18:53:32
In reply to Re: Generic Celexa Won't Happen: see bottom » Simcha, posted by pharmrep on September 1, 2002, at 16:59:45
>*** where do you get your info on Celexa being "knocked off" formulary?
Logic my man. Pure logic. Since Lexapro is supposed to be the "New and Improved Celexa" and it will be priced cheaper than Celexa, insurance companies *WILL* notice and dump Celexa from the formulary. It's simple economics.
>I dont think that will happen...Forest is not trying to have "happy" Celexa patients switch to Lexapro...just those who "need" to for adverse event reasons. And to concur..generic Celexa not in US til late 2005....
Um, I beg to differ. I still see no research that tells me that Lexapro is anything more than just another SSRI. Lexapro is 1/2 of what Celexa is and yes it still would take 20mg of Lexapro to equal 40mg of Celexa. This is my effective dose. The side effect profile for 20mg of Lexapro and 40mg of Celexa are not statistically significant.
>PS Will somebody tell Simcha about Howard Soloman and his story (and his son) so maybe this way Simcha might see Forest in a different light.
Um Forest Labs is soooo very far away from its early days. Now it is no more than any other Drug Giant.
If Forest were really so benificent then they would give up their patent for an allegedly inferior drug (Celexa) so that more patients might at least be able to afford it while introducing the lower-priced Lexapro. Instead we will see insurance companies drop the more expensive version of Forest's drug, Celexa, from their formularies. No, this is a marketing strategy to force Lexapro into market dominance.
>PPS...the above point about waiting til patent out is what GlaxoSmithKline did with Paxil...Paxil CR was approved by FDA 3 years ago, but only came out this year...when the original Paxil expires...the public and Dr's are learning this and are not happy....sorry it happens Simcha...but really...Forest isnt a bad cookie and is trying to do the right thing...by promoting the better med.)Forest is just doing it differently. Please use common sense, economics, and marketing savvy then tell me if their plan is not about forcing Celexa out so that Lexapro will rise to the top.
Posted by pharmrep on September 1, 2002, at 18:55:07
In reply to Re: 'Dr Theory' » pharmrep, posted by dr. dave on September 1, 2002, at 18:47:56
OK Dr Dave...lets just say we agree to disagree...you have one intrepretation to the studies and their conclusions you have read and I tend to agree with the studies. I will say this...I dont like the extra hype on Lexapro...I would rather just be able to give the Dr's I see the studies and samples like all pharmreps do, and let the Dr's decide for themselves...is there a place for this med, will it be able to help some of my patients where other meds dont, and once comfortable maybe new patients can try it as well.
Posted by Dinah on September 1, 2002, at 18:57:55
In reply to Re: Please be civil, posted by LostBoyinNC1 on September 1, 2002, at 18:37:12
> I am keeping the discussion on the issues. If you cant see that, you need to learn logic.
>Thats basic argumentative writing 101 Dinah, it has nothing to do with "being civil."
>Lost Boy, I should have added that further discussion of posting policies should take place at PB Administration. However, I will offer this.
This site is not the place for argumentative writing, Lost Boy. It is designed for support and education. Education can be offered in ways that are not argumentative, and on this site it must be offered in non-argumentative ways, or the site cannot fulfill its supportive function.
As I said below, I hope you choose to stay and follow the civility guidelines so that you will be able to continue to offer education.
Also, for future reference, the civility guidelines also apply to comments addressed to me.
Any further discussion of posting policies or administrative matters should be directed to PB Administration.
Dinah
Posted by Dinah on September 1, 2002, at 19:03:28
In reply to Re: Lexapro side-effects, posted by LostBoyinNC1 on September 1, 2002, at 18:52:08
>
> You have a lot of gaul telling people on here, sick people who have serious medical problems that they should "be objective" when you yourself are about as biased as a person can be. Youre a Lexapro drug salesman for Forest Labs.
>
> LostBoyinNC
Sorry, Lost Boy. I asked you before to be civil, so I have had to block you from posting for one week.
Posted by pharmrep on September 1, 2002, at 19:08:40
In reply to Re: Generic Celexa Won't Happen: Simple Economics » pharmrep, posted by Simcha on September 1, 2002, at 18:53:32
> >*** where do you get your info on Celexa being "knocked off" formulary?
>
> Logic my man. Pure logic. Since Lexapro is supposed to be the "New and Improved Celexa" and it will be priced cheaper than Celexa, insurance companies *WILL* notice and dump Celexa from the formulary. It's simple economics.
>
> >I dont think that will happen...Forest is not trying to have "happy" Celexa patients switch to Lexapro...just those who "need" to for adverse event reasons. And to concur..generic Celexa not in US til late 2005....
>
> Um, I beg to differ. I still see no research that tells me that Lexapro is anything more than just another SSRI. Lexapro is 1/2 of what Celexa is and yes it still would take 20mg of Lexapro to equal 40mg of Celexa. This is my effective dose. The side effect profile for 20mg of Lexapro and 40mg of Celexa are not statistically significant.
>
> >PS Will somebody tell Simcha about Howard Soloman and his story (and his son) so maybe this way Simcha might see Forest in a different light.
>
> Um Forest Labs is soooo very far away from its early days. Now it is no more than any other Drug Giant.
>
> If Forest were really so benificent then they would give up their patent for an allegedly inferior drug (Celexa) so that more patients might at least be able to afford it while introducing the lower-priced Lexapro. Instead we will see insurance companies drop the more expensive version of Forest's drug, Celexa, from their formularies. No, this is a marketing strategy to force Lexapro into market dominance.
>
>
> >PPS...the above point about waiting til patent out is what GlaxoSmithKline did with Paxil...Paxil CR was approved by FDA 3 years ago, but only came out this year...when the original Paxil expires...the public and Dr's are learning this and are not happy....sorry it happens Simcha...but really...Forest isnt a bad cookie and is trying to do the right thing...by promoting the better med.)
>
> Forest is just doing it differently. Please use common sense, economics, and marketing savvy then tell me if their plan is not about forcing Celexa out so that Lexapro will rise to the top.****Do you know how managed care works? Just because Lexapro is less than Celexa, doesnt mean Celexa will get bumped off formulary. They will both be high on the formularies ahead of other AD's. Forest is not trying to "remove" Celexa. And there is a lot more to Lexapro than being "1/2 of Celexa" in fact if you are on 40mg of Celexa...then 10mg of Lexapro would be the equivalent..not 20mg. Do you have access to any of the studies? If not...keep checking the posts (or web)...they are out there. And "doing it differently" is the right thing to do...bring the better med to the public if thats what it is.
Posted by winger on September 1, 2002, at 19:34:32
In reply to Re: sex. s/e (let's try this one more time -newby) » Winger, posted by pharmrep on September 1, 2002, at 18:19:09
I have had some side effects with the effexor.. flushing, some sexual side effects although nothing major - thougth at higher doses I got the jitters and lots of physical side effects like shakes and spasams much like what you read about with the serotonin syndrome... BP seems fine so far though that is a concern of mine as high BP runs in my familly. As to withdrawal.. I tried Paxil a long time ago, when I first started having anxiety problems, and had terrible agitation and nervousness from it.. I didn't have a psych doctor then, and decided to just stop it.. The funny thing is, I felt Terrific for a week or two.. the most relaxed and in control I have been in years... I guess I was still getting the serotonin effects of the medication without the side effects, and had absolutely no withdrawal other than that.. my doctor was amazed.. same for the zoloft..
the Buspar was bad though... I lost about thirty pounds and years off my life getting off that medication!! But it wasn't as bad with the zoloft...And I would definitely try the Lexapro sans Buspar first..! it's just something I read in a study and was curious about.. I definitely will avoid that drug if possible.. It's also funny, the Buspar is supposed to take a long time to start working, but it helped me almost immediately..
I also know about the fact that at the dose I'm taking, Effexor really just an SSRI, that's one reason I want to try another SSRi .. at higher doses of Effexor, I can't take it... it's like speed to me....
Just goes to show how different all of us are!!
This is really all just one big experiment on all of us.. but it's one of the only shots we have short of doping up on the benzo drugs... or joining a tibetin monastery!!! :)
You sound like you know your stuff... at least you are giving reasonable info to people...!
It's all about what works for the individual, and about taking it slow and getting a doctor that will work with you and help you along...
no quick fix for any of this sad to say!!
I really think our modern lifestyle is the ultimate culprit - especially in our formative years.. but I'm not ready to chuck it all just yet
Ciao!!
Dave
> ** No joke...sexual s/e can be tough with SSRI's...I know it is a tough trade for some...treating the depressive componants vs sex s/e. I have heard of the buspar..and others like wellbutrin added on to SSRI's. It seems that your dose can be low enough for you and that the AD still works. Effexor is usually an SNRI, but at doses below 150 it is still an SSRI. How are you doing with the s/e? Are you experiencing increased sweating, increased blood pressure (you have to check your blood pressure with Effexor), dizziness, nausea, somnolence, insomnia, ejac disorder, or anything else? Most of all...like Paxil, you need to be aware of discontinuation s/e with Effexor...this is an AD you cant just stop and switch with..if you do...you might experience agitation, anorexia, anxiety, confusion, impaired coordination, fatigue, vertigo, vomiting,dry mouth, nervousness, and the earlier mentioned s/e. If you do try Lexapro...try it without the Buspar 1st to see if you even need it...you might not.
Posted by Simcha on September 1, 2002, at 20:28:59
In reply to Re: Simple Economics? » Simcha, posted by pharmrep on September 1, 2002, at 19:08:40
>****Do you know how managed care works? Just because Lexapro is less than Celexa, doesnt mean Celexa will get bumped off formulary. They will both be high on the formularies ahead of other AD's.
Yes, I've had many HMOs and I know how they work. I have a cousin in that business. The HMOs are heartless entities who don't really care about what you really need. All they want to do is "control costs" so that profit is maximized.
>Forest is not trying to "remove" Celexa. And there is a lot more to Lexapro than being "1/2 of Celexa" in fact if you are on 40mg of Celexa...then 10mg of Lexapro would be the equivalent..not 20mg.
Actually I've read extensively about Escitalopram for years. I've been watching its arrival. All the studies I know say that I'd need 20mg to equal 40mg of Celexa.
>Do you have access to any of the studies? If not...keep checking the posts (or web)...they are out there. And "doing it differently" is the right thing to do...bring the better med to the public if thats what it is.
No, they are doing the same underhanded game of economics that other drug companies play just differently. Mark my words. HMOs will eliminate Celexa from their formularies once they see that Lexapro is cheaper. All they really care about is cost.
I still have yet to see a study that proves that Lexapro is a better med than Celexa. That trial will really come once it gets prescribed for years. I'm not willing to jump into this experiment quite yet.
Still Sceptical,
Simcha
Posted by pharmrep on September 2, 2002, at 1:49:45
In reply to Re: Simple Economics?, posted by Simcha on September 1, 2002, at 20:28:59
> >****Do you know how managed care works? Just because Lexapro is less than Celexa, doesnt mean Celexa will get bumped off formulary. They will both be high on the formularies ahead of other AD's.
>
> Yes, I've had many HMOs and I know how they work. I have a cousin in that business. The HMOs are heartless entities who don't really care about what you really need. All they want to do is "control costs" so that profit is maximized.
>
> >Forest is not trying to "remove" Celexa. And there is a lot more to Lexapro than being "1/2 of Celexa" in fact if you are on 40mg of Celexa...then 10mg of Lexapro would be the equivalent..not 20mg.
>
> Actually I've read extensively about Escitalopram for years. I've been watching its arrival. All the studies I know say that I'd need 20mg to equal 40mg of Celexa.
>
> >Do you have access to any of the studies? If not...keep checking the posts (or web)...they are out there. And "doing it differently" is the right thing to do...bring the better med to the public if thats what it is.
>
> No, they are doing the same underhanded game of economics that other drug companies play just differently. Mark my words. HMOs will eliminate Celexa from their formularies once they see that Lexapro is cheaper. All they really care about is cost.
I still have yet to see a study that proves that Lexapro is a better med than Celexa. That trial will really come once it gets prescribed for years. I'm not willing to jump into this experiment quite yet.
>
> Still Sceptical,
> Simcha** I'm not sure what studies you've read, but in just the last year or so...9 have come out in the US. Have you seen anything from Jack Gorman, William Burke, C. Sanchez (microdialysis), Lydiard, or Greenblatt? These are the most recent, and ones the FDA used to approve in the US. They all show different mg's of both drugs, but I assure you, 10mg of Lexapro (the lowest dose) is "at least as effective as" 40mg of Celexa (The higher titrated dose)...taking 20mg of Lexapro is too much to start...besides, I thought you said you liked Celexa...why switch?
PS........Why would Celexa get bumped...it will be #3 in price behind only generic Prozac and Lexapro? I still dont think it will get bumped.
Posted by selena on September 2, 2002, at 2:04:41
In reply to Ok, posted by pharmrep on September 1, 2002, at 18:55:07
pharmrep I think your information is very informative thank you for giving it. The more information the better, we can all look around the internet for a counterpoint if we want to, yours is just information like any other. thanks again
Posted by oracle on September 2, 2002, at 3:06:15
In reply to Re: Blocked for one week » LostBoyinNC1, posted by Dinah on September 1, 2002, at 19:03:28
> Sorry, Lost Boy. I asked you before to be civil, so I have had to block you from posting for one week.
This will be the 3-4th time he has been blocked, I think he is due for more than 1 week
Posted by oracle on September 2, 2002, at 4:01:17
In reply to Cheap, Generic Celexa, posted by moxy1000 on September 1, 2002, at 14:14:07
> 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?
Simple, more slices of the pie mean more money.
In general everyone rushes to the latest, so they will have 2 patents in force at the same time for the same chemical (an isomer). While it may seem that it would be better to release Lexapro when Celexa's patent runs out, I don't think it works this way. Having both patents in force means they see the profits sooner. It should take at least 2 years for the general population to indicate yea or nay on this one.
It is also a BIG leap to say they are doing this because Lexapro is better; this is about profit.
And, in truth, it should be ! Don't expect business to be run any way else, or they are doomed to fail.
Posted by pharmrep on September 2, 2002, at 9:49:55
In reply to Re: Cheap, Generic Celexa, posted by oracle on September 2, 2002, at 4:01:17
> 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?
>
> Simple, more slices of the pie mean more money.
> In general everyone rushes to the latest, so they will have 2 patents in force at the same time for the same chemical (an isomer). While it may seem that it would be better to release Lexapro when Celexa's patent runs out, I don't think it works this way. Having both patents in force means they see the profits sooner. It should take at least 2 years for the general population to indicate yea or nay on this one.
> It is also a BIG leap to say they are doing this because Lexapro is better; this is about profit.
> And, in truth, it should be ! Don't expect business to be run any way else, or they are doomed to fail.
>
>***Actually...it should take about about 6-12 months...not 2+ years for Lexapro to prove itself. And how does a Pharm Co. just go about "saying" (Product-X) is better without having any facts...that would fly real well with the competition and public right....Forest would get killed if it hung its hat on unfounded claims. I agree that this is a business...of course we make money and earn decent livings, but what's wrong with that? Don't you too? Just because this is in medicine doesnt make it impossible to make a good "business" decision and an ethical morally based move at the same time.
Posted by Geezer on September 2, 2002, at 11:48:31
In reply to Re: Cheap, Generic Celexa, posted by oracle on September 2, 2002, at 4:01:17
Good point Oracle. I wish there was more incentive for the drug companies to develope NEW and improved drugs. At present this is not possible due to the "jack-boot bureaucrats" at the FDA (the federal government is far less altruistic than the drug companies).
So what are the alternatives? We could turn the whole matter over to the liberal/socialists who would in turn burden us with national health care (more taxes, less health care and the loss of liberty). I can think of a few (not all) of the possible improvments. Establish a regulatory agency in the private sector (get rid of the FDA). Show us a 50% reduction in taxes so we could contract for our own health care. One thing the government could do is put a cap on judgements and some additional controls on tort lawyers.
Just some thoughts - thanks for the post.
Geezer
Posted by pharmrep on September 2, 2002, at 12:03:50
In reply to Re: Cheap, Generic Celexa, posted by Geezer on September 2, 2002, at 11:48:31
> Good point Oracle. I wish there was more incentive for the drug companies to develope NEW and improved drugs. At present this is not possible due to the "jack-boot bureaucrats" at the FDA (the federal government is far less altruistic than the drug companies).
>
> So what are the alternatives? We could turn the whole matter over to the liberal/socialists who would in turn burden us with national health care (more taxes, less health care and the loss of liberty). I can think of a few (not all) of the possible improvments. Establish a regulatory agency in the private sector (get rid of the FDA). Show us a 50% reduction in taxes so we could contract for our own health care. One thing the government could do is put a cap on judgements and some additional controls on tort lawyers.
>
> Just some thoughts - thanks for the post.
>
> Geezer** you two are funny...if you want to be in dreamland..why not just eliminate taxes altogether?
PS Lexapro is improved over Celexa...the incentive was that the FDA encourages the idea of isomer science and any possibility of a drug to be "cleaned up" and show data of improvement gets the FDA's attention...the Citalopram mixture was just lucky enough to be able to do this successfully...not all drugs lend themselves to be able to be "cleaner." For example, Paxil and Zoloft are already the isomers, Effexor cant,and Prozac tried twice but it didnt help (it actually hurt.)
Posted by JaneB on September 2, 2002, at 12:49:34
In reply to Re: alternatives » Geezer, posted by pharmrep on September 2, 2002, at 12:03:50
Why don't the study results indicate any positive conclusions about fewer ASE's or daytime sleepiness?
Appreciate your info.
JaneB
Posted by pharmrep on September 2, 2002, at 14:41:51
In reply to Lexapro study effectspharmrep, posted by JaneB on September 2, 2002, at 12:49:34
> Why don't the study results indicate any positive conclusions about fewer ASE's or daytime sleepiness?
> Appreciate your info.
> JaneB** Why do you think they dont? There are studies that show reduced s/e with Lexapro...here is a post from a couple days ago that has the FDA approved package insert info.
Re: Lexapro side-effects » dr dave
If you have any questions...I'd be glad to help if I can.
Posted by pharmrep on September 2, 2002, at 14:44:59
In reply to lexapro (P.I.) dose dependant adverse events, posted by pharmrep on September 1, 2002, at 0:00:38
> Some of the more common adverse events (as listed in the package insert) are as follows:
>
> adverse event......Placebo.(311 patients)/...10mg Lexapro.(310 patients)/...20mg Lexapro (125 patients)
> insomnia..............4%.................................7%..........................................14%
> diarrhea..............5%.................................6%..........................................14%
> dry mouth...........3%.................................4%...........................................9%
> somnolence.........1%.................................4%...........................................9%
> dizziness..............2%.................................4%...........................................7%
> sweating increased1%.................................3%...........................................8%
> constipation.........1%.................................3%...........................................6%
> fatigue.................2%.................................2%...........................................6%
> indigestion...........1%.................................2%...........................................6%
>
> The overall incidence rates of adverse events in 10mg Lexapro treated patients (66%) is similar to that of the placebo treated patients (61%), while the incidence rate in 20mg Lexapro treated patients was greater (86%).***oops...didnt attach, so I just posted again.
Posted by moxy1000 on September 2, 2002, at 15:21:57
In reply to Re: Cheap, Generic Celexa, posted by oracle on September 2, 2002, at 4:01:17
Seems to be a lot of people saying that "lexapro is half of Celexa." Okay...that's true, I guess. But that seems to be over simplifying things a bit.
Let's look at science.
Celexa is a racimic compound that contains the s and r enantiomers in equal proportion (50:50). These means essentially that they are stereoisomers.
There are many stereoisomers in nature - look for instance at carvone - s-carvone it is responsible for the taste and smell of caraway, while r-carvone is responsible for the taste and smell of spearmint.
Not really the same thing at all, is it?
Another example, both lemons and oranges contain a compound called limonene - however Lemons have the enantiomer s-limonene, while oranges have the enantiomer r-limonene. As a result, lemons smell and taste sour, while oranges smell and taste sweet.
Just because isomers are mirror images of eachother, does not mean they are the same thing at all. Science proves that.
In the case of Lexapro, the reason it is more potent comes down to receptor sites in the body.
Ready for more science? Receptor sites are very selective - the correct key is required for binding. However, they are not 100% selective. Similar molecules, or similar "keys" may be able to fit into or bind with the same receptor. The binding may be only partial, but it may be enough to keep another receptor binder from latching on.
This is the case with Celexa. The r-enantiomer was not a perfect fit for blocking the reuptake of serotonin. It fit "partially" with the cells. The s-enantiomer IS a perfect fit, but the presence of the r-enantiomer actually interfered with the ability of the s-enantiomer to increase serotonin levels in the brain.
I have tried to stay away from getting into isomer science, as I found it initially difficult to understand and I didn't want to bore anyone with the specifics, but this discussion seems to warrant a bit more depth in discussion regarding the science behind this isomer called Lexapro.
The point is, like caraway and spearmint, like oranges and lemons, Celexa and Lexapro are not the same. They act totally differently at the receptor sites - one is a perfect fit, and the other is not. The result is Lexapro being over 100 times (or in other words, 100%) more potent then the r-enantiomer in the inhibition of serotonin reuptake.
Do the math. Does logic tell you that one should work more efficiently then the other??
P.S. Dr. Dave, I'm not a scientist or a doctor, but I have done my homework, and contrary to your assumption, I do understand the pharmacodynamics.
Posted by moxy1000 on September 2, 2002, at 15:23:11
In reply to Re: Cheap, Generic Celexa, posted by oracle on September 2, 2002, at 4:01:17
Seems to be a lot of people saying that "lexapro is half of Celexa." Okay...that's true, I guess. But that seems to be over simplifying things a bit.
Let's look at science.
Celexa is a racimic compound that contains the s and r enantiomers in equal proportion (50:50). These means essentially that they are stereoisomers.
There are many stereoisomers in nature - look for instance at carvone - s-carvone it is responsible for the taste and smell of caraway, while r-carvone is responsible for the taste and smell of spearmint.
Not really the same thing at all, is it?
Another example, both lemons and oranges contain a compound called limonene - however Lemons have the enantiomer s-limonene, while oranges have the enantiomer r-limonene. As a result, lemons smell and taste sour, while oranges smell and taste sweet.
Just because isomers are mirror images of eachother, does not mean they are the same thing at all. Science proves that.
In the case of Lexapro, the reason it is more potent comes down to receptor sites in the body.
Ready for more science? Receptor sites are very selective - the correct key is required for binding. However, they are not 100% selective. Similar molecules, or similar "keys" may be able to fit into or bind with the same receptor. The binding may be only partial, but it may be enough to keep another receptor binder from latching on.
This is the case with Celexa. The r-enantiomer was not a perfect fit for blocking the reuptake of serotonin. It fit "partially" with the cells. The s-enantiomer IS a perfect fit, but the presence of the r-enantiomer actually interfered with the ability of the s-enantiomer to increase serotonin levels in the brain.
I have tried to stay away from getting into isomer science, as I found it initially difficult to understand and I didn't want to bore anyone with the specifics, but this discussion seems to warrant a bit more depth in discussion regarding the science behind this isomer called Lexapro.
The point is, like caraway and spearmint, like oranges and lemons, Celexa and Lexapro are not the same. They act totally differently at the receptor sites - one is a perfect fit, and the other is not. The result is Lexapro being over 100 times (or in other words, 100%) more potent then the r-enantiomer in the inhibition of serotonin reuptake.
Do the math. Does logic tell you that one should work more efficiently then the other??
P.S. Dr. Dave, I'm not a scientist or a doctor, but I have done my homework, and contrary to your assumption, I do understand the pharmacodynamics.
Posted by JaneB on September 2, 2002, at 15:24:11
In reply to Re: Lexapro study effects » JaneB, posted by pharmrep on September 2, 2002, at 14:41:51
> > Why don't the study results indicate any positive conclusions about fewer ASE's or daytime sleepiness?
> > Appreciate your info.
> > JaneB
>
> ** Why do you think they dont? There are studies that show reduced s/e with Lexapro...here is a post from a couple days ago that has the FDA approved package insert info.
> Re: Lexapro side-effects » dr dave
> If you have any questions...I'd be glad to help if I can.Pharmrep,
What about antidepressant induced sexual dysfunction? I saw the results you posted. Am I missing something or has this issue not been evaluated with Lexapro? What if 40 mg Celexa causes cycling and 20 mg is used. Can/should 10 mg Lexapro be cut in half to avoid this risk? I know package inserts don't cover these intricate side effects. Just wondered if you have inside information.
JaneB
Posted by winger on September 2, 2002, at 15:46:12
In reply to Re: Lexapro study effects, posted by JaneB on September 2, 2002, at 15:24:11
I missed out.. what is cycling??
> > > Why don't the study results indicate any positive conclusions about fewer ASE's or daytime sleepiness?
> > > Appreciate your info.
> > > JaneB
> >
> > ** Why do you think they dont? There are studies that show reduced s/e with Lexapro...here is a post from a couple days ago that has the FDA approved package insert info.
> > Re: Lexapro side-effects » dr dave
> > If you have any questions...I'd be glad to help if I can.
>
> Pharmrep,
>
> What about antidepressant induced sexual dysfunction? I saw the results you posted. Am I missing something or has this issue not been evaluated with Lexapro? What if 40 mg Celexa causes cycling and 20 mg is used. Can/should 10 mg Lexapro be cut in half to avoid this risk? I know package inserts don't cover these intricate side effects. Just wondered if you have inside information.
> JaneB
>
>
>
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