Posted by Adam on May 16, 2000, at 19:18:55
In reply to Going back on a medicine you've taken before, posted by Angela on May 16, 2000, at 17:41:05
That's a good question.
I don't really understand what "poop-out" is, but have heard it described
as a form of tolerance.I would have guessed that this "tolerance" was to the effects of dysregulation
of the serotonergic system, where the compensatory adjustments made by the
nervous system to enhanced serotonin neurotransmission (which are what some
theories of antidepressant action implicate as the clinically relevant
phenomena) are somehow "normalized". Since the number of serotnin-secreting
neurons in the brain is quite small, and these neurons function largely to
regulate other, larger structures containing neurons secreting other hormones
like, say, dopamine, perhaps the difficulties have to do with desisitization
of other neurotransmitter systems.Or maybe there is further adjustment of serotonin secretion months or even
years after starting the medication. The theories I have heard proposed to
explain the delayed onset of SSRI action involve negative feedback on
serotonin production and secretion through stimulation of somatodendritic
autoreceptors. There is an initial DECREASE in serotonin in the synapse after
initiation of treatment, or, at least, no significant increase, due to this
negative feedback. Eventually, though, the overstimulation of these
autoreceptors causes their down-regulation, and the pre-synaptic neuron
becomes "apathetic" to its own activity, returning to a normal level of
serotonin secretion, the affect of which is now augmented by the inability
of the cell to draw the hormone back in from the synapse. Maybe, somehow,
this "apathy" is overcome, and serotonin secretion again decreases.Whatever the mechanism, it seems to me that simply replacing one SSRI immediately
with another would be of little benefit, since the effects on serotonin are
more-or-less the same.I would look into alternative classes of medicaion. Effexor might be one
choice, since it has effects on the norepinepherine system too. You could
try to augment Zoloft with Welbutrin, which acts primarily on dopamine and
norepinepherine. Or you could switch to an MAOI, which acts on all three
of the major psychogenic monoamines. Augmentation with lithium might kick-
start something in the serotonin system. Addition of gabapentin seems to have
helped some non- or partial responders to SSRIs for a variety of indications.There are a number of things one could try.
But based on my totally unprofessional hypothesizing about these various
neurotransmitter systems that nobody has worked out well yet, I wouldn't predict
treating SSRI poop-out with another SSRI, or, for that matter, returning to
the old "pooped-out" drug, would be the way to cure the problem.> my doctor isn't happy with the results the luvox has dealt me, so i asked him if we could switch back to zoloft. he agreed to it and told me to start titrating down tomorrow & gave me a whole schedule to follow.
>
> my concern is that the zoloft will not be effective on me anymore. what is the response when you go off a medicine then go back on it? i've been on the luvox for at least 6 weeks and i've gotten a little bit better, but not to the point i was at on zoloft or celexa.
>
> any experiences you've had would be great to hear about. thanks!
poster:Adam
thread:33667
URL: http://www.dr-bob.org/babble/20000508/msgs/33696.html