Posted by Racer on August 4, 2004, at 17:09:02
In reply to MAOI poop-out?, posted by Ilene on August 4, 2004, at 16:00:30
Based solely on a very incomplete understanding of all this stuff, I don't think MAOIs stop working the same way SSRIs do. (And don't even *think* about asking me about TCAs!)
SSRIs work by inhibiting the reuptake of serotonin, right? That means that they're affecting the serotonin receptors, which first spew out some serotonin -- then suck some of it back in, to keep the balance of serotonin in the synapse where they think it should be. The SSRIs depend on the serotonin that's already there, and then on that receptor 'listening' to the drug. What seems to happen with this mechanism -- again, I'm so close to totally ignorant about this stuff, so don't consider this the final answer -- is that the serotonin receptors pay attention for a while, but then get desensitized to the message and go back to what they were doing in the first place.
MAOIs, on the other hand, inhibit the action of an enzyme that contributes to the breakdown of the Big Three neurotransmitters -- serotonin, norepinephrine, and dopamine. Without that enzyme going about bashing our friendly little one-amino-acid neurotransmitters, the little guys can come out and play to their hearts content. Again, it depends on having enough of the neurotransmitters in the first place, but it's not so dependant on the receptors.
I think that the biggest difference is that MAOIs don't depend on the reuptake inhibition, so much on the survival of the neurotransmitter molecule itself. Does that make sense?
Anyway, while I will not say that MAOIs shouldn't poop out the way some other drugs can, I hope this will hold you over until someone who actually *knows* anything about this comes along.
poster:Racer
thread:374083
URL: http://www.dr-bob.org/babble/20040730/msgs/374106.html