Posted by SFY on May 28, 2006, at 15:47:50
In reply to Though EMSAM Bipassed Liver and Other Internal Or, posted by Phillipa on May 28, 2006, at 14:17:48
EMSAM does deliver selegiline directly into the blood thereby significantly reducing its exposure to the GI tract. But because blood flows to all internal organs including the liver, intestines, and stomach there will be some selegiline exposure which explains why some people are having GI tract-related side effects.
According to one study:
Transdermal delivery of selegiline provides several pharmacological advantages over oral delivery. First, it sufficiently reduces exposure of the gastrointestinal tract to the drug to limit inhibition of intestinal MAOA activity. Thus, adequate gastrointestinal MAOA enzyme is left
intact to metabolize dietary tyramine. Second, transdermal administration of selegiline circumvents first-pass hepatic metabolism, which results in sustained high plasma levels of the parent compound with a concomitant decrease in metabolite formation. This provides sufficient brain concentrations of selegiline to produce an antidepressant effect, presumably involving substantial MAOA as well as MAOB inhibition. This also may permit the expression of additional pharmacological properties of selegiline other than MAO inhibition previously observed in vitro. At the same time, there is less exposure to L-methamphetamine and L-amphetamine metabolites than observed with oral selegiline.http://ajp.psychiatryonline.org/cgi/content/full/159/11/1869
The EMSAM drug insert clearly states that at least 1 in 100 users may experience GI-related side effects such as "Constipation, flatulence, anorexia, gastroenteritis, vomiting."
poster:SFY
thread:649762
URL: http://www.dr-bob.org/babble/20060525/msgs/649801.html