Posted by Adam on August 31, 2001, at 17:29:09
In reply to Re: MAOIs and safety, posted by IanSFO on August 29, 2001, at 19:41:29
I was on "the patch" for six months. I ate and imbibed anything I wanted, sometimes in large quantities, but, unfortunately, drug interactions are still an issue. One needs to observe the same cautions with OTC and prescription drugs that one does on high-dose oral selegiline (and low-dose, for that matter), and the other non-selective MAOIs.
The reason for this is fairly simple: MAO-A, which somehow retains function in the intestines (so they say) while one is on transdermal selegiline, can deaminate tyramine sufficiently to protect one from hypertensive reactions to it. But, since MAO-A is not involved in breaking down the vast majority of drugs you take into your system, you are still susceptible to any enhanced CNS and/or sympathetic/parasympathetic effects a drug might cause in the presence of a non-selective MAOI.
I've been waiting quite a while for some explanation as to why transdermal selegiline "protects the gut" from MAO-A inhibition. As far as I can gather, no one knows for sure. Since it can inhibit MAO-A perfectly well in the CNS (to where it traveled via the circulation), but seems to have no effect on enteral epithelial or smooth-muscle enzymes, there must be some exclusion mechanism, I would guess. Maybe stuff enters the circulation from the gut, but the reverse is not always true.
There's a decent article on some relevant stuff here:
http://www.mhsource.com/pt/p010525.html
(Just as an aside, Dr. Bodkin was the principle investigator of the study I was in, and Dr. Detke was the physician who followed me throughout the trial I participated in...both I hold in the highest esteem, and were by far the best psychiatrists I have worked with since I was in a study at the NIH years ago.)
> I'm also curious about the potential for drug interactions when using the deprenyl patch. Bypassing the digestive system may eliminate the danger of tyramine reactions, but does it eliminate dangers from drug reactions? Does anyone know?
>
poster:Adam
thread:76778
URL: http://www.dr-bob.org/babble/20010828/msgs/77131.html