Posted by PaulB on December 2, 2001, at 14:03:07
In reply to Re: SSRIs and MAOIs for SP » PaulB, posted by Elizabeth on December 1, 2001, at 14:11:59
> > > Inhibition of MAO probably increases serotonin concentrations to a greater degree than serotonin reuptake blockade does: metabolism of serotonin by MAO accounts for a lot more of the "cleanup" of stray serotonin than does reuptake into cells.
> > >
> > Thats a great theory and you may be right
>
> I think it's more than just a theory: I bet that if we did some research, we could uncover plenty of evidence showing that quite a bit more serotonin is eliminated by metabolism (via MAO) than by reuptake. In any case, there are many reasons to suppose that this is true.
>
> > Let me get this straight. Your not saying Fluoxetine is more powerful than Sertraline although I agree Sertraline competetes with Celexa and Paxil. I may have misunderstood you here.
>
> That might be. Try reading it again -- I hope I wasn't too unclear. If there's something there that didn't make sense, please let me know and I will try to clarify it.
>
> The point of what I was trying to say is that "potent" has a specific meaning, and it does not mean the same thing as "effective" or "strong." Saying that Prozac is more "potent" than Zoloft doesn't mean that Prozac is a stronger AD or that it works better than Zoloft; it just means that Prozac works at much smaller *doses*. (A person who feels well on 20 mg of Prozac would probably feel no effect at all from 20 mg of Zoloft, for example, but 50 or 75 mg of Zoloft might work just as well as the 20 mg of Prozac for that person.)>I understand. At the therapeutic dose Sertraline would block the serotonin re-uptake pump more powerfully than Prozac at its theraputic dose but not at Prozacs therapeutic dose.
> > > > The reason I would prefer to take a SSRI than a MAOI is because of their selectivity which allows them to work for longer.
> > >
> > Allows them to work for longer? I'm not sure how you came to this conclusion.???
> > >
> > I tried to explain but couldnt. We can agree to differ and thats okay. I would add that Venlafaxine worked for two weeks and paroxetine worked for seven months so????.
>
> Okay, if I read you right, it sounds like you're saying that you concluded that Paxil's selectivity made its effects last longer than those of Effexor. (Please let me know if I've got it wrong -- I want to help.) There are a couple of problems with this reasoning.
>
> First of all, you can't generalize what happened to you and assume that it says something about what the drug usually does. People have an amazing variety of responses to these drugs, for reasons that we just don't understand yet. So, what happened to you may have nothing to do with what happens for most people. And indeed, your particular situation is not a common one; it's specific to you, and while there is probably someone out there who had a similar experience, it's certainly not the usual result of trying Paxil and Effexor separately. There probably is no "usual result" -- people's response patterns vary so much.
>
> Second, you can't draw the conclusion that the selectivity difference is what made Paxil work for a while while Effexor only seemed to work for two weeks. There are differences between these drugs that we don't know about. For whatever reason, it's possible that Paxil just works better for you than Effexor does.>
> Also, since Paxil worked for such a brief time (a few months really isn't that long), it's possible that what you were experiencing was a temporary lift in your mood, and not a true drug response. This is actually pretty common. Depression and other long-lasting conditions often get better temporarily (for a few days, a few weeks, or even a few months), and the hope that comes with a new medication can also cause your mood to lift for a while.
>
> The same principle applies to the Effexor, even more so since you said the Effexor worked for only two weeks. Two weeks really isn't long enough to know if an AD is working at all. If you were feeling better in the first two weeks that you were taking Effexor, it probably wasn't due to the Effexor -- it probably was a coincidence. It's likely that what you had was not a true drug response, but a temporary improvement, which may have been contributed to by your and your doctor's hope that the new medicine would work. But again, this doesn't mean that the improvement was a response to the medication.
>
> So, my guess is that, for whatever reason, Effexor didn't work for you. The Paxil may have worked and "pooped out" after a brief time, or it may not have been working at all, either. But again, we don't know *why* this would be, and we don't have any reason to believe that selectivity would cause drugs to work longer. (SSRIs do poop out quite often. So do other types of ADs. There's no evidence that it is less likely to happen with SSRIs.)>I believe, in my case that if there is little serotonin in the brain causing depression, anxiety and its various subtypes then blocking the re-uptake pump of just a few serotonin pumps will allow what little serotonin there is to circulate for longer at those few sites. With the SSRI's this is usually 5-HT1a, 5-HT2a and c and 5-HT3. I dont think Venlafaxine has that advantage because it is an SRI. To understand the adavnatage of the SSRIs as apposed to the SRI Venlafaxine you need only to look at their names.
> > I have recurrant bouts of depression and with Paroxetine I found that the effect lasted much longer than Venlafaxine which is not selective.
>
> Right, but as I've explained, that doesn't mean that selectivity is the reason that Paxil worked longer (or -- and this seems more likely -- that Paxil worked and Effexor did not). Sometimes people don't respond to one SSRI but a different SSRI will work; we don't know why this is, but it is true.> Okay
> I'd be interested to know what dose of Effexor you were taking and how long you took it, if you can recall.
> I was prescribed 75mg of the slow-release form of Effexor once a day in November 1999. I noticed a benefit after two weeks and this lasted for about 2 weeks before 'poop-out'. My physician did not think an increase in dosage would be beneficial. In April of that year I was prescribed Paxil(Seroxat over here) and the antidepressant/anxiety effect lasted for six months.
> > Yes you know experts say we think that these pills work by increasing norepinephrine and dopamine but we cannot say for sure although I think we all know that there is a monoamine increase that exerts the antidepressant effect.
>
> Well, the monoamine increase causes a cascade of other things to happen. I think researchers believe that it is one (or more) of these indirect effects that causes the relief from depression. One thing that we do know is that the old "monoamine hypothesis" of depression is not the correct explanation -- it used to be thought that depression was caused by inadequate amounts of monoamines, but we now know it's more complicated. How much more complicated, and what the real answer is, nobody knows.I agree. There is now much focus on substance p and its relationship with depression. The discovery of the first substance P antagonist (Cp-96,345) was made by scientists at pfizer. they have used this as a starting point to develop a series of compounds, with improved selectivity and potency and which block the activation of nerves in the locus ceruleus-one of the areas involved in mood regulation. There are also hormone based approaches being developed. Medicines that modify the hormonal changes that underlie depression. Disturbances in the HPA axis are common in depression.
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> >I would add that the newer MAOI's can be effective as the older 'irreversible' MAOIs if they are prescibed in very high doses.http://members.tripod.com/~cyberpsy/JWGTiller.htm
Also you could go to mhsource.com site and look up an article entitled 'the Canadian Experience with RIMAs by Russell T.Joffe, MD, Psychiatric Times , June 1996, Vol X111 Issues 6> -elizabeth
>
> p.s. Typing in all-caps is usually considered to mean that you're "shouting." I know that's not what you meant by it, but in the future, it'd probably be a good idea to avoid all-caps, so as to prevent misunderstandings.
poster:PaulB
thread:85575
URL: http://www.dr-bob.org/babble/20011202/msgs/85811.html