Posted by vanvog on March 19, 2013, at 12:59:47
In several threads on Psycho-Babble the 1mg/1kg rule has been generally acknowledged as an rule-of-thumb, 0,8 1,5mg/kg according to Chairman_MAO. I did some research on the internet and could find nothing of this sort anywhere else. Basically all Ive found is 1 outside source stating that MAO Inhibition, contrary to a wide-held assumption might not be all that important at all for the therapeutic effect of Parnate and we can assume that there are far more complicated psychopharmacological effects nobody seems to have found out anything about yet.
Based on a study with Phenelzin we know that a MAO inhibition of 80% or 85% seems to be significant for a positive therapeutic effect.This report examines the hypothesis that for phenelzine to be more effective than placebo it is necessary to achieve at least 80% inhibition of platelet MAO activity. This hypothesis was examined in the context of a double-blind comparison of phenelzine, amitriptyline and placebo in depressed patients. When phenelzine became significantly more effective than placebo at 4 weeks, the average MAO inhibition was 85%. By the 5th week, with MAO inhibition greater than 90%, phenelzine was significantly more effective than amitriptyline. A highly significant correlation was noted between improvement and MAO inhibition within the phenelzine group.
Heres the abstract of the study: http://www.ncbi.nlm.nih.gov/pubmed/7231652
Unfortunately, the following abstract doesnt contain anything relevant other than:
[] the rate of MAO inhibition at Week 2 was significantly correlated with clinical improvement at Week 2 and final response status. These findings could not be explained by other potentially moderating variables such as sex, age, endogenicity, recurrence, and incapacitation.
http://www.ncbi.nlm.nih.gov/pubmed/2298705
There is renewed interest in the clinical pharmacology of phenelzine sulfate and other monoamine oxidase (MAO) inhibitors. Newer clinical and analytic techniques recently have been applied to investigations of this class of drugs in man. The results show that drugs such as phenelzine are effective in nonendogenous depression and phobic disorders. Clinical response to phenelzine is related to platelet MAO inhibition and dosage per unit body weight. High percent MAO inhibition in platelets at two weeks is associated with greater improvement after a six-week course of treatment. Our data show that a safe, effective phenelzine dose in 1 mg/kg body weight per day. These results have delineated the pharmacologic and therapeutic effects of phenelzine and support a continuing role for MAO inhibitors in psychopharmacology.
http://www.ncbi.nlm.nih.gov/pubmed/365127
Unfortunately I cant get my hands on the following studies:
http://www.ncbi.nlm.nih.gov/pubmed/6736280
http://www.ncbi.nlm.nih.gov/pubmed/6865965
http://www.ncbi.nlm.nih.gov/pubmed/2008794
I dont have any access to the following study either, but a secondary source from a foreign Tranylcypromine manufacturer states that:
http://www.ncbi.nlm.nih.gov/pubmed/3922441
Extensive and controlled studies for a correlation of MAO inhibition (measured in the Platelets) and the therapeutic effect of Tranylcypromine do not exist. In a study with 14 Patients (20 to 60 mg/day Tranylcypromine) a correlation could not be established. Simpson at al. (1985) found 3 hours after a single dose of 10 mg Tranylcypromine a MAO inhibition in the platelets of 66% and 72% after 24 hours. They discussed that an explanation of therapeutic differences could not be given on the basis of the variability of the MAO inhibition alone because even with low doses high MAO inhibition could be achieved. They concluded that on the basis of clinical dose effect of Tranylcypromine there must be additional pharmacological effects of Tranylcypromine which contribute to the antidepressant effect.
(My own translation. English is not my first language but you should get the idea.)
poster:vanvog
thread:1040654
URL: http://www.dr-bob.org/babble/20130308/msgs/1040654.html