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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 11 of 11. This is the beginning of the thread.
Posted by raisinb on November 25, 2008, at 15:00:38
I've been trying to plan ahead and figure out whether the increased cost of Lexapro will be worth it or not, and I can't find any information about which SSRI is likely to be more potent.
I've read several things that say Paxil is the most potent SSRI, but can't find anything on these two. Anyone know whether Zoloft or Lexapro is likely to be more powerful, all other things being equal?
Posted by mav27 on November 25, 2008, at 16:13:08
In reply to zoloft vs lexapro--difference in potency?, posted by raisinb on November 25, 2008, at 15:00:38
zoloft is the most potent, followed by paxil. I'm not sure where lexepro fits in but ciprimil in next so it might be around that.
Posted by mav27 on November 25, 2008, at 16:22:56
In reply to zoloft vs lexapro--difference in potency?, posted by raisinb on November 25, 2008, at 15:00:38
Yeah so its zolfolt > paxil > lexepro > ciprimil
Posted by Phillipa on November 26, 2008, at 0:47:40
In reply to Re: zoloft vs lexapro--difference in potency? » raisinb, posted by mav27 on November 25, 2008, at 16:22:56
No wonder my first ad was only l0mg of paxil and yes that one caused me many problems even with benzos and lopressor for three months. And brain zaps getting off. Now zoloft doesn't touch me at 50mg didn't go further don't know why? Lexapro during peri-menopause was intolderable anxiety with benzos xanax I think. Love Phillipa
Posted by bleauberry on November 26, 2008, at 13:52:14
In reply to zoloft vs lexapro--difference in potency?, posted by raisinb on November 25, 2008, at 15:00:38
They are all potent as heck! :-)
Not sure where the other poster got the information, but as I understand it Paxil is the most potent, followed by Lexapro and then Zoloft. Not sure where Cymbalta fits in there, but it is highly potent as well, much more so than Effexor. In terms of action specifically on serotonin, Lexapro is the most specific. Paxil has a little effect on NE, Zoloft a little on dopamine at the highest doses.
All that being said, potency has nothing to do with whether it will work for one person or another. There are other known things at play, and even many many more unknown things at the genetic, molecular, and hormonal levels. For example, someone who has a depression that they are convinced is serotonin related, two or three of the SSRIs might not work that great, while a third one works like a miracle, and the third one could easily be the least potent of them all. I doubt serotonin potency is going to be much help in choosing a med.
Posted by mav27 on November 26, 2008, at 18:04:29
In reply to Re: zoloft vs lexapro--difference in potency?, posted by bleauberry on November 26, 2008, at 13:52:14
the potency's can be seen here
http://www.preskorn.com/books/ssri_s3.htmlIn the first chart which is for seratonin..and as the key says 'the lower the number the higher the potency'
Lexapro is mentioned further down as a 1.5 which puts it just before celexa (or in clomipramines spot)
Posted by bleauberry on November 26, 2008, at 19:01:58
In reply to Re: zoloft vs lexapro--difference in potency? » bleauberry, posted by mav27 on November 26, 2008, at 18:04:29
Thanks to mav27 for the excellent referral to the preskorn website.
According to graph 3.7, 50mg Zoloft, 20mg Prozac, or 20mg Paxil have equal potency, each inhibiting the serotonin reuptake pump by 80%.
Posted by Phillipa on November 26, 2008, at 19:28:45
In reply to Re: zoloft vs lexapro--difference in potency?, posted by bleauberry on November 26, 2008, at 19:01:58
Since luvox can potentiate other meds how do you see luvox? Thanks Phillipa
Posted by mav27 on November 26, 2008, at 19:32:15
In reply to Re: zoloft vs lexapro--difference in potency?, posted by bleauberry on November 26, 2008, at 19:01:58
In the same graph you can see how it takes different plasma levels to reach that 80%. zoloft only takes 25 ng/ml for 80% uptake inhibition whereas paxil takes 40 ng/ml to reach 80% uptake inhibition which is what makes the zoloft much more potent.
Prozac being one of the weaker ones takes 200 ng/ml to cause 80% reuptake inhibition.
> According to graph 3.7, 50mg Zoloft, 20mg Prozac, or 20mg Paxil have equal potency, each inhibiting the serotonin reuptake pump by 80%.
Posted by bleauberry on November 28, 2008, at 10:18:28
In reply to Re: zoloft vs lexapro--difference in potency? » bleauberry, posted by mav27 on November 26, 2008, at 19:32:15
I do understand these meds have different potencies when compared on a pound-per-pound kind of basis. But when comparing normal dose to normal dose, they are basically equal. In the end, it actually makes no difference. Someone could, and they have, for example do poorly on Zoloft at its proper inhibition level, and yet do great on Prozac with only half of its proper inhibition level, and not feel better until reaching twice the plasma level of Paxil. All this number crunching is meaningless in the real world.
But I understand the original post was asking which was more potent, and the graphs do show that in a detailed way.
> In the same graph you can see how it takes different plasma levels to reach that 80%. zoloft only takes 25 ng/ml for 80% uptake inhibition whereas paxil takes 40 ng/ml to reach 80% uptake inhibition which is what makes the zoloft much more potent.
>
> Prozac being one of the weaker ones takes 200 ng/ml to cause 80% reuptake inhibition.
>
> > According to graph 3.7, 50mg Zoloft, 20mg Prozac, or 20mg Paxil have equal potency, each inhibiting the serotonin reuptake pump by 80%.
>
>
Posted by raisinb on November 30, 2008, at 8:13:31
In reply to zoloft vs lexapro--difference in potency?, posted by raisinb on November 25, 2008, at 15:00:38
Well, thank you everyone, for the information.
I feel pretty good right now, so I may just continue the combo of 50 mg Zoloft and 10 of Lexapro.
This is the end of the thread.
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