Posted by MARTY on April 17, 2006, at 16:15:05
In reply to Re: SCOTT, Questions about high dose Parnate, posted by SLS on April 17, 2006, at 10:02:12
Hi Scott --Doesn't downregulating 5-HT2 suppose to help with sexual side-effects of AD ?
Thank,
Marty
> Hi Tyler.
>
> Chairman_MAO has more experience with high-dose Parnate therapy and might be better able to answer your questions.
>
> Yes, people have gone higher than 150mg. I have seen people go as high as 200mg. I believe Chairman_MAO reported experiencing less insomnia along with less daytime fatigue and sleepiness at higher dosages.
>
> One abstract on Medline describes that high dosage, but not low dosage, Parnate treatment resulted in a downregulation of 5-HT2 receptors. 5-HT2 antagonism is thought to have value when treating depression or the negative symptoms of schizophrenia.
>
>
> - Scott
>
> -------------------------------------------
>
>
> 168: J Neural Transm Suppl 1994;41:127-34
>
> Comparisons of the actions of high and low doses of the MAO inhibitor
> tranylcypromine on 5-HT2 binding sites in rat cortex.
>
> Goodnough DB, Baker GB
>
> Department of Psychiatry, University of Alberta, Edmonton, Canada.
>
> Tranylcypromine (TCP) is a commercially available antidepressant drug, and
> recent literature reports suggest that high doses of this drug may be
> particularly effective in treating refractory depression. Down-regulation of
> 5-HT2 receptors in rat cortex is an effect produced after chronic administration
> of several antidepressants, and we have conducted a chronic study comparing low-
> and high-dose TCP in this regard. Male Sprague-Dawley rats were administered TCP
> (0.5 or 2.5 mg/kg/day) or vehicle (distilled water) via Alzet minipumps
> implanted subcutaneously in the dorsal thoracic area. Groups of rats were killed
> 4, 10 or 28 days after pump implantation and whole cortex was dissected out and
> utilized for preparation of a membrane fraction. Binding studies were performed
> with this fraction using 3H-ketanserin as the radioligand. Down-regulation
> (decrease in Bmax) of the 5-HT2 binding site was observed in high-dose animals
> after 10 and 28 days but not after 4 days. Low-dose TCP had no effect on 5-HT2
> densities at any time interval. The affinity of 3H-ketanserin for the 5-HT2 site
> was not affected by either dose at any time interval. These results suggest that
> down-regulation of the 5-HT2 site may contribute to the efficacy of high-dose
> TCP in the treatment of refractory depression.
>
> PMID: 7931218, UI: 95016589
>
>
>
poster:MARTY
thread:634096
URL: http://www.dr-bob.org/babble/20060417/msgs/634207.html