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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 18 of 18. This is the beginning of the thread.
Posted by conundrum on April 15, 2010, at 23:05:04
Do these drugs have any action at this receptor. I read that amitriptyline is an inverse agonist at this receptor and I believe imipramine is an antagonist or inverse agonist.
Does anyone know if this applies to their metabolites as well?
Posted by SLS on April 22, 2010, at 12:03:32
In reply to Nortriptyline, Desipramine, 5 HT2C?, posted by conundrum on April 15, 2010, at 23:05:04
How silly of me not to see your post.
- Scott
Posted by conundrum on April 22, 2010, at 14:14:32
In reply to Re: Nortriptyline, Desipramine, 5 HT2C? » conundrum, posted by SLS on April 22, 2010, at 12:03:32
LOL, its weird, I thought maybe you were just trying to reword it better so someone would answer, or that you saw but didn't read it and your subconscious mind decided to ask.
Wish someone knew. Seems like most of the afinity information on TCAs focuses on the 5 HT2A receptors. I think blocking the 5HT 2A/C receptors are important for increasing motivation and focus.
Posted by SLS on April 22, 2010, at 17:29:28
In reply to Re: Nortriptyline, Desipramine, 5 HT2C? » SLS, posted by conundrum on April 22, 2010, at 14:14:32
> I think blocking the 5HT 2A/C receptors are important for increasing motivation and focus.
I sure could use some of that.
- Scott
Posted by conundrum on April 23, 2010, at 7:06:41
In reply to Re: Nortriptyline, Desipramine, 5 HT2C? » conundrum, posted by SLS on April 22, 2010, at 17:29:28
I wonder if psychiatrists have books with information in it that we just don't know about?
Posted by desolationrower on April 23, 2010, at 18:47:38
In reply to Re: Nortriptyline, Desipramine, 5 HT2C? » SLS, posted by conundrum on April 23, 2010, at 7:06:41
> I wonder if psychiatrists have books with information in it that we just don't know about?
nah
go to http://pdsp.med.unc.edu/pdsp.php, then do a search, and it will have links to the studies where they found the binding affinity. thats the best place ot get started.
-d/r
Posted by conundrum on April 24, 2010, at 23:59:47
In reply to Re: Nortriptyline, Desipramine, 5 HT2C?, posted by desolationrower on April 23, 2010, at 18:47:38
Thanks for the link! I did some search and found that nortriptyline had a potency of 8.5 at the 5 HT2C receptor which is pretty high and desipramine had a lower potency of 244 at this same receptor.
Nortriptyline's potency at the 5 HT2A receptor was 5. The range for desipramine at 5 HT2A was around 100.
Nortriptyline was also slightly less post a NRI than desipramine.
Unfortunately, I do not have a pubmed account so could not see these numbers in their original content, just the results from the query.
Posted by bulldog2 on April 26, 2010, at 8:58:32
In reply to Re: Nortriptyline, Desipramine, 5 HT2C? » desolationrower, posted by conundrum on April 24, 2010, at 23:59:47
> Thanks for the link! I did some search and found that nortriptyline had a potency of 8.5 at the 5 HT2C receptor which is pretty high and desipramine had a lower potency of 244 at this same receptor.
>
> Nortriptyline's potency at the 5 HT2A receptor was 5. The range for desipramine at 5 HT2A was around 100.
>
> Nortriptyline was also slightly less post a NRI than desipramine.
>
> Unfortunately, I do not have a pubmed account so could not see these numbers in their original content, just the results from the query.
>
>I am having problems with this link. Could you please find out how clomipramine does at this link.
Posted by conundrum on April 26, 2010, at 11:43:45
In reply to Re: Nortriptyline, Desipramine, 5 HT2C? » conundrum, posted by bulldog2 on April 26, 2010, at 8:58:32
Well you search by receptor not by drug. So if there was a specific receptor and you were wondering how potent clomipramine was there I could tell you.
Posted by bulldog2 on April 26, 2010, at 13:43:48
In reply to Re: Nortriptyline, Desipramine, 5 HT2C? » bulldog2, posted by conundrum on April 26, 2010, at 11:43:45
> Well you search by receptor not by drug. So if there was a specific receptor and you were wondering how potent clomipramine was there I could tell you.
clomipramine for 5htc2
Lithium 5htc2
Posted by conundrum on April 26, 2010, at 14:30:55
In reply to Re: Nortriptyline, Desipramine, 5 HT2C?, posted by bulldog2 on April 26, 2010, at 13:43:48
There were three KI results for clomipramine from three different tests:
64.00, 52.00, 22.00
Couldn't find anything for lithium on that receptor.
Posted by bulldog2 on April 26, 2010, at 16:00:42
In reply to Re: Nortriptyline, Desipramine, 5 HT2C? » bulldog2, posted by conundrum on April 26, 2010, at 14:30:55
> There were three KI results for clomipramine from three different tests:
>
> 64.00, 52.00, 22.00
>
> Couldn't find anything for lithium on that receptor.
>
>Thanks do you have the link to the table
Thanks
bulldog2
Posted by desolationrower on April 27, 2010, at 2:51:03
In reply to Re: Nortriptyline, Desipramine, 5 HT2C?, posted by bulldog2 on April 26, 2010, at 13:43:48
you can search for all ki values for a drug.
just choose the drug from the pulldown menue called 'hot ligand'. i can't link directly to it, as it uses some kind of scripting.
it doesn't have lithium though, as its an element not a drug, i guess. heres a review of some of the things lithium does http://ajol.info/index.php/ajpsy/article/viewFile/30159/22778
-d./r
Posted by conundrum on April 27, 2010, at 11:14:17
In reply to Re: Nortriptyline, Desipramine, 5 HT2C?, posted by desolationrower on April 27, 2010, at 2:51:03
Posted by conundrum on April 27, 2010, at 13:24:23
In reply to Re: Nortriptyline, Desipramine, 5 HT2C?, posted by desolationrower on April 27, 2010, at 2:51:03
Actually that doesn't really work. The hot ligand drop down menu just lets you select the ligand that the drug you want is being compared to. Some drugs that bind strongly are in there like paroxetine, mianserin, etc, but some like clomipramine I didn't see.
Posted by desolationrower on May 7, 2010, at 19:30:58
In reply to Re: Nortriptyline, Desipramine, 5 HT2C? » desolationrower, posted by conundrum on April 27, 2010, at 13:24:23
oh, yeah its 'test ligand' not 'hot ligand' sorry
-d/r
Posted by Brainbeard on May 24, 2010, at 13:28:27
In reply to Re: Nortriptyline, Desipramine, 5 HT2C?, posted by desolationrower on May 7, 2010, at 19:30:58
Gillman lists a much weaker affinity of nortriptyline for 5HT2A: only 44. He lists a Ki value of 29 for its mother drug, amitriptyline. 35 for clomipramine.
Surely, desipramine is a much more potent NRI than nortriptyline. Gillman lists 0.83 versus 10, respectively.
Gillman unfortunately doesn't mention affinities for 5HT2C receptors.
The problem with binding affinity studies is that Ki values usually vary so wildly that they don't really tell you anything.
Posted by Conundrum on May 24, 2010, at 20:54:09
In reply to Receptor Infinities, posted by Brainbeard on May 24, 2010, at 13:28:27
Nice topic title. Here is the search results for Nortriptyline for some reason there are two entries:
and
It would be nice to know if these drugs were antagonists or inverse agonists at the receptors they block. So it looks like nortriptyline is definitely "dirtier" than desipramine. It has the benefit of more 5HT2A/C antagonism and the boon of anticholinergic and anti-histaminergic actions. Desipramine is almost pure noradrenline. Good if you just need NE, if you need any antagonism probably would have to add Remeron or some antipyschotic at a low dose. Nortriptyline will be more sedating and could cause lethargy and weight gain and desipramine should be activating, and may cause tachyardia. But I guess you all knew that.Almost forgot Protriptyline not much on that:
For a more visual comparison check this out:
http://www.mindandmuscle.net/forum/index.php?showtopic=38276&pid=552949&mode=threaded&show=&st=0
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