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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 16 of 16. This is the beginning of the thread.
Posted by bipolarspectrum on February 15, 2004, at 3:17:24
Hi,
I was wondering if anyone knew where ritanserin can be found.. Its supposedly a very interesting drug which is selective for 5-ht2a receptors!!!
Posted by Sad Panda on February 15, 2004, at 5:57:45
In reply to RITANSERIN - availabe on earth??, posted by bipolarspectrum on February 15, 2004, at 3:17:24
> Hi,
> I was wondering if anyone knew where ritanserin can be found.. Its supposedly a very interesting drug which is selective for 5-ht2a receptors!!!
>How about Mianserin?, it sounds close enough :)
Lots of drugs are 5-HT2a antagonists.Cheers,
Panda.
Posted by linkadge on February 15, 2004, at 6:53:11
In reply to Re: RITANSERIN - availabe on earth?? » bipolarspectrum, posted by Sad Panda on February 15, 2004, at 5:57:45
Cyproheptadine, "periactin" would be pretty similar.
Posted by crazychickuk on February 15, 2004, at 8:10:34
In reply to Re: RITANSERIN - availabe on earth??, posted by linkadge on February 15, 2004, at 6:53:11
what r these then? what they for? i am interested to know....
Donna
Posted by Chairman_MAO on February 15, 2004, at 8:23:09
In reply to Re: RITANSERIN - availabe on earth??, posted by crazychickuk on February 15, 2004, at 8:10:34
None of those other drugs others have mentioned are "clean". The notable thing about ritanserin is that it has no h1 blocking activity (mianserin, mirtazapine, cyproheptadine, trazodone) or a1 blocking activity (trazodone, nefazodone). Come to think of it, are there any other selective 5ht2 blockers marketed anywhere? :)
Posted by Sad Panda on February 15, 2004, at 8:58:17
In reply to Re: RITANSERIN - availabe on earth??, posted by Chairman_MAO on February 15, 2004, at 8:23:09
> None of those other drugs others have mentioned are "clean". The notable thing about ritanserin is that it has no h1 blocking activity
>How do you know that? I can't find any data that says it is "clean"
Cheers,
Panda.
Posted by Chairman_MAO on February 15, 2004, at 13:32:08
In reply to Re: RITANSERIN - availabe on earth?? » Chairman_MAO, posted by Sad Panda on February 15, 2004, at 8:58:17
To me, "very selective" is tantamount to "clean".
Check it out.
A new 5-HT2 antagonist (ritanserin) in the treatment of chronic headache with depression. A double-blind study vs amitriptyline
by
Nappi G, Sandrini G, Granella F, Ruiz L,
Cerutti G, Facchinetti F, Blandini F, Manzoni GC
Dept. of Neurology IRCCS C. Mondino,
University of Pavia, Italy.
Headache 1990 Jun; 30(7):439-44ABSTRACT
The exact relationship between depression and chronic headache remains unclear. Considerable clinical and pharmacological evidence suggests the existence of a common biological terrain. Many antidepressant drugs are effective in the treatment of migraine and chronic headache disorders. Ritanserin, a new very selective serotonin-2 (5-HT2) antagonist, has recently shown both analgesic and antidepressant properties. The present study compares in a double-blind design, the effectiveness of ritanserin and amitriptyline, a well-known antidepressant extensively used in migraine prophylaxis. Thirty-eight patients (30 females and 8 males ranging in age from 20 to 50 yrs) were classified according to the International Headache Society criteria as: patients with chronic tension-type headache (CTH) (11 cases) and patients with coexisting migraine and CTH (MCTH) (27 cases). Only patients with a score equal to or higher than 18 on the Hamilton Rating Scale for Depression (HRSD) were included. Ritanserin was highly effective in reducing Pain Total Index and analgesic consumption in chronic headache, and its activity was similar to that observed during amitriptyline treatment. A significant improvement of HRSD and HRSA (Hamilton Rating Scale for Anxiety) scores was observed during both treatments. The main results of our study concern the demonstration of antiheadache and antidepressive properties of ritanserin. To better define the profile of the patients and their clinical responsiveness to the treatment, dexamethasone suppression test, clonidine test and nociceptive flexion reflex were investigated in our patients. Our data confirm the usefulness of these methods as markers of chronic headache with depression.
Posted by Questionmark on February 16, 2004, at 1:12:12
In reply to RITANSERIN - availabe on earth??, posted by bipolarspectrum on February 15, 2004, at 3:17:24
> Hi,
> I was wondering if anyone knew where ritanserin can be found.. Its supposedly a very interesting drug which is selective for 5-ht2a receptors!!!i know! i can't stand how impossible it is to find a selective 5-ht2a antagonist! And if ritanserin is it, i freaking wish it would be available too.
Posted by Sad Panda on February 16, 2004, at 2:35:53
In reply to Re: RITANSERIN - availabe on earth?? » Sad Panda, posted by Chairman_MAO on February 15, 2004, at 13:32:08
Data here: http://www.gpcr.org/7tm/ligand/Organon/Tablig/LIG_C87051432.html suggests it has afinnity for a bunch of other receptors too. Doesn't really look that much different to Mianserin.
Cheers,
Panda.
Posted by Chairman_MAO on February 16, 2004, at 12:06:01
In reply to Re: RITANSERIN - availabe on earth?? » Chairman_MAO, posted by Sad Panda on February 16, 2004, at 2:35:53
How do I reconcile these data with the abundance of journal articles calling it either "selective" or "very selective"? I wish I were trained in interpreting different types of binding constants!
Posted by Sad Panda on February 16, 2004, at 20:49:39
In reply to Re: RITANSERIN - availabe on earth?? » Sad Panda, posted by Chairman_MAO on February 16, 2004, at 12:06:01
> How do I reconcile these data with the abundance of journal articles calling it either "selective" or "very selective"? I wish I were trained in interpreting different types of binding constants!
>
>I don't believe in the term 'selective' anymore since it was abused by SSRI marketers(Paxil & Prozac) Efexor is another one from the marketers, if Efexor is a SNRI than surely Zoloft must be a SDRI.
Cheers,
Panda.
Posted by Chairman_MAO on February 16, 2004, at 21:35:53
In reply to Re: RITANSERIN - availabe on earth?? » Chairman_MAO, posted by Sad Panda on February 16, 2004, at 20:49:39
The term has been abused, but the term "SNRI" is a misleading acronym that actually means "Serotonin Norepinephrine Reuptake Inhibitor". At the doses you need to block the DA reuptake pump with Zoloft, you'd be UeberSaturating(sm) the SE reuptake pump. This is not selective. ;)
I believe selective just means a 10-fold difference in binding affinity.
Posted by Sad Panda on February 16, 2004, at 22:47:42
In reply to Re: RITANSERIN - availabe on earth?? » Sad Panda, posted by Chairman_MAO on February 16, 2004, at 21:35:53
> The term has been abused, but the term "SNRI" is a misleading acronym that actually means "Serotonin Norepinephrine Reuptake Inhibitor". At the doses you need to block the DA reuptake pump with Zoloft, you'd be UeberSaturating(sm) the SE reuptake pump. This is not selective. ;)
>
> I believe selective just means a 10-fold difference in binding affinity.When I said SDRI I meant Serotonin Dopamine Reuptake Inhibitor. Sertraline's affinity for blocking Dopamine reuptake is nearly as potent an Velafaxine's affinity for blocking Norepinephrine reuptake, which isn't saying much for Venlafaxine's 'dual action'.
From http://www.psychotropical.com/notes/613.html
"of the 100 or more CNS receptors currently known, not to mention ion channels and enzymes, most of these drugs have not come within experimental shouting distance of one tenth of them. So exactly what they may or may not be specific for is largely unknown."It's 4 years old, but still a valid statement.
Cheers,
Panda.
Posted by Chairman_MAO on February 17, 2004, at 10:56:29
In reply to Re: RITANSERIN - availabe on earth?? » Chairman_MAO, posted by Sad Panda on February 16, 2004, at 22:47:42
Oh, it didnt occur to me that you meant "serotonin" and not "selective". Personally, I _DETEST_ those acronyms. I believe Shire actually calls Adderall a NDmA, or "Norepinephrine/Dopamine modulating Agent". Uhh, yeah, modulation. That says a lot! How about a "CRaP, or Catecholamine Releaser and Potentiator" Makes about as much sense. I wish pharma companies would stop naming their products as if they were Microsoft. And what the hell is with "Symbyax", anyway? Sounds either like an alien warlord or the name of a prostitute in Gary, Indiana.
I believe the difference is that sertraline's Ki is 0.29 for the SE reuptake pump and venlafaxine's is around 10. Thus, you could TOLERATE the dose of venlafaxine to meaningfully inhibit NE reuptake, but the amount of sertraline you'd need for significant DA reuptake would make things quite uncomfortable (or more uncomfortable then venlafaxine, at least, because at 375mg/day, that's not terribly comfortable on all fronts either, mainly libidinal/genital numbness). Am I right here? People seem to think I know a lot, but I'm getting the feeling that you're more knowledeable with some of the technical stuff. I, just seem to have a pretty good intution for knowing how a lot of drugs influence behavior. This is why I am going back to school, so I can hopefully do something with this talent--legally. Do you have a background in this field of any kind?
Posted by Sad Panda on February 18, 2004, at 7:23:44
In reply to Re: RITANSERIN - availabe on earth?? » Sad Panda, posted by Chairman_MAO on February 17, 2004, at 10:56:29
> Oh, it didnt occur to me that you meant "serotonin" and not "selective". Personally, I _DETEST_ those acronyms. I believe Shire actually calls Adderall a NDmA, or "Norepinephrine/Dopamine modulating Agent". Uhh, yeah, modulation. That says a lot! How about a "CRaP, or Catecholamine Releaser and Potentiator" Makes about as much sense. I wish pharma companies would stop naming their products as if they were Microsoft. And what the hell is with "Symbyax", anyway? Sounds either like an alien warlord or the name of a prostitute in Gary, Indiana.
>
> I believe the difference is that sertraline's Ki is 0.29 for the SE reuptake pump and venlafaxine's is around 10. Thus, you could TOLERATE the dose of venlafaxine to meaningfully inhibit NE reuptake, but the amount of sertraline you'd need for significant DA reuptake would make things quite uncomfortable (or more uncomfortable then venlafaxine, at least, because at 375mg/day, that's not terribly comfortable on all fronts either, mainly libidinal/genital numbness). Am I right here? People seem to think I know a lot, but I'm getting the feeling that you're more knowledeable with some of the technical stuff. I, just seem to have a pretty good intution for knowing how a lot of drugs influence behavior. This is why I am going back to school, so I can hopefully do something with this talent--legally. Do you have a background in this field of any kind?
>
>I have no background at all in this stuff, but since it affects me I've taken a big interest in it. I don't know much about anything, but I do know where to find the answers. :) I don't know anything about mood stabilizers/anti-convulsants & the only thing they let BP people have here in Australia is Lithium, so I hope I don't have BP2, I am waiting in a queue for a visit to a pdoc for a proper DX.
I believe you are correct with Venlafaxine's affinity for 5-HT v NE in that it's about 5:1. At 75mg it's just another SSRI, at 300-375mg it starts heavily blocking NE reuptake. I think Sertraline 5-HT v DA maybe as close as that or maybe be more like 10:1 depending on which study you read. Of all the studies & abstracts I have read about about SSRI's, Sertraline is the one that appears to be above average & also seems to be the safest. If Efexor+Remeron is a failure I would like to try Sertaline next, I'd try & cross taper on to it from Efexor.
"libidinal/genital numbness" I have zero libido at 225mg of Venlafaxine, but Remeron (called Avanza here) has returned functionality. If my wife asks for it, I get excited & can perform, but if she doesn't ask, I would never think of sex. It's like Venlafaxine blocks Testosterone from the brain. Something else that truely bugs me is Efexor is spelt with one F here, not two, wierd. :)
Cheers,
Panda.
Posted by micro on February 19, 2004, at 13:04:31
In reply to Re: RITANSERIN - availabe on earth?? » Chairman_MAO, posted by Sad Panda on February 16, 2004, at 22:47:42
> > The term has been abused, but the term "SNRI" is a misleading acronym that actually means "Serotonin Norepinephrine Reuptake Inhibitor". At the doses you need to block the DA reuptake pump with Zoloft, you'd be UeberSaturating(sm) the SE reuptake pump. This is not selective. ;)
> >
> > I believe selective just means a 10-fold difference in binding affinity.
>
> When I said SDRI I meant Serotonin Dopamine Reuptake Inhibitor. Sertraline's affinity for blocking Dopamine reuptake is nearly as potent an Velafaxine's affinity for blocking Norepinephrine reuptake, which isn't saying much for Venlafaxine's 'dual action'.
>
> From http://www.psychotropical.com/notes/613.html
> "of the 100 or more CNS receptors currently known, not to mention ion channels and enzymes, most of these drugs have not come within experimental shouting distance of one tenth of them. So exactly what they may or may not be specific for is largely unknown."
>
> It's 4 years old, but still a valid statement.
>
> Cheers,
> Panda.
>
>
>
>
> Hello, I believe that SNRI is brief for Selective Norepinephrine Reuptake Inhibitor{ Straterrra}. There is no serotonergic action.
Does that help? Regards, Micro
>
>
This is the end of the thread.
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