Posted by SLS on February 16, 2003, at 10:46:48
In reply to Re: ANYONE ON SELEGELINE? QUESTIONS... » JohnL, posted by Craig Allen on February 15, 2003, at 7:26:45
Selegiline, once called l-deprenyl, was initially researched and developed as an antidepressant. Quite a bit of money was poured into getting it approved as such. Selegiline is different from the other irreversible MAOIs (Parnate, Marplan, and Nardil) in that it binds to the MAO-B form of monoamine-oxidase much more strongly than it does to MAO-A. MAO-B metabolizes dopamine (DA). MAO-A metabolizes both norepinephrine (NE) and serotonin (5-HT). At low dosages, it was found that selegiline was selective for the MAO-B enzyme. Generally speaking, it is the MAO-A enzyme that seems to be the more important when treating depression.
Selegiline is *selective*, but not *specific*. At dosages above 10mg, selegiline begins to inhibits MAO-A in addition to MAO-B. At the low dosages used initially, it proved to be a disappointment. However, it was subsequently studied to evaluate its utility in treating Parkinsons Disease , a disorder involving the degeneration of neurons that utilize dopamine as their neurotransmitter. Selegiline demonstrated enough efficacy to be approved by the FDA for Parkinsons, but not depression.
In order to work as an antidepressant monotherapeutically in severe depression, it seems that the dosage of selegiline must be greater than 10mg per day. No longer being selective, it inhibits both MAO enzymes similar to Parnate and Nardil. At the point where MAO-A becomes significantly inhibited, the same dietary restrictions that must be followed for Parnate and Nardil apply with selegiline as well. This is true for oral administration. However, when used as a patch (transdermal delivery), the MAO-A along the digestive tract is bypassed, preventing the hypertensive food-reaction. Another advantage of the transdermal patch is that it maintains a constant blood level of selegiline throughout the day. People often report that the quality of their antidepressant response is significantly better and qualitatively different than that they experience with oral selegiline.
Selegiline can make a good augmentor of standard antidepressants. It can do so at dosages lower than what are necessary for its use as monotherapy. On Psycho-Babble, I see quite a few people report success using 5.0mg of selegiline in this fashion. Low dosages might also be effective for dysthymia, ADD / ADHD, chronic fatigue syndrome, and perhaps Alzheimers Dementia. My guess is that the reason low dosages of selegiline are effective for the former three is that it is metabolized into methamphetamine in the body, and that it methamphetamine that produces the improvements in mood, energy, and attentional deficits.
I forgot what the question was. :-)