Posted by Adam on March 16, 2000, at 23:15:43
In reply to Re: Bidding Goodbye to the Patch, posted by Annie on March 16, 2000, at 20:26:17
Selegiline HCl is, at low doses, a selective inhibitor of monoamine oxidase (MAO) B, an enzyme that modifies and thus deactivates neurotransmittors like dopamine and b-phenylethylamine. In that regard it differs from the classic MAOIs, which have rather equal affinities for both isoforms of MAO. MAO-A metabolizes serotonin, norepinephrine, and, to a lesser extent, dopamine, so combined inhibition of both effectively boosts the availability of the big three, and thus packs quite an antidepressive puch for some people.
Selegiline, being more "dopaninergic" is used as an adjuctive therapy to l-dopa for people with Parkinson's disease, as it increases the availability of both endogenous dopamine as well as the drug form to combat the dopamine deficiency in Parkinson's sufferers' brains (due to the degeneration and loss of dopaminergic cells). The maximum approved dose for that indication is 10mg/day.
At doses above 10mg/day, though, selegiline's low affinity for MAO-A becomes important. At doses above 40mg, inhibition of both MAO-A and B is near complete, and thus it behaves, in that respect, like any other MAOI currently on the market. Selegiline has a number of other interesting properties though, not the least of which is its metabolism into amphetamines (albeit the less-potent "levo" forms as opposed to the "dextro" forms found in designer drugs and dexedrine, for instance). Selegiline also may block dopamine reuptake, seems to stimulate the upregulation of tyrosine hydroxylase (a rate-limiting enzyme important in NE and DA synthesis) and the production of superoxide dismutase (antioxidant). Like other MAOIs, (think of Parnate, which is pretty amphetamine-like itself, and Nardil, which is a potent GABAnergic) it a bit of polypharmacy in a pill, and all this stuff together probably account for its therapeutic effect.
It seems many people don't respond at all to it. I didn't respond to just about anything else I tried, and did very well on selegiline. I may do well on another MAOI, but I'd like to stick to selegiline if I can, since I don't want to play around with a new drug if at all possible. Many docs are willing to prescribe it, and I guess other people can get some sort of coverage. I certainly think its a worthwhile thing for anyone to try, if they've given many other things a shot, but my reaction to selegiline is about as good as it gets, I guess. I certainly don't want to be denied that now, after having come so far.
> I never heard of such an antidepressant as the one you've discussed here. Maybe if all else fails I'll have to try that. Have you had nonresponive drug therapies much of the time? I have and became afraid to say it after awhile. But I got back to telling it how it is now, thank God for small wonders. Anne
poster:Adam
thread:27239
URL: http://www.dr-bob.org/babble/20000312/msgs/27268.html