Posted by SLS on September 12, 2021, at 21:26:49
In reply to Re: ritanserin, pimavanserin, and lumateperone » SLS, posted by undopaminergic on September 12, 2021, at 13:54:19
Hi again.
> You don't mention asenapine (Sycrest, Saphris). This is currently my main candidate.I didn't know that about asenapine. Is it an inverse-agonist? I think you're looking at the right one, if for no other reason than I have seen it work long-term in a friend of mine to produce an improvement in both mood and cognition. However, she has schizoaffective disorder, bipolar-type. However, asenapine could not prevent the manic psychosis that she experienced as a reaction to Effexor. When I tried asenapine, I received a mild-moderate antidepressant effect that lasted for about a week before it capitulated to my supremely stubborn brain. I like asenapine. I found it to be a very clean drug with respect to side effects, including sedation or brain-fog.
I understand that most of the atypical antipsychotics are actually inverse-agonists of the 5-HT2a/c receptors. However, I read one paper that said specifically that asenapine was a pure antagonist and not an inverse agonist at 5-HT2a receptors with little affinity for 5-HT2c receptors. Asenapine causes virtually no weight gain compared to the great amount of weight gain with olanzapine and clozapine.
https://journals.sagepub.com/doi/10.1177/2045125311430112
"It is perhaps surprising that asenapine shares the high relative affinities at 5-HT2C and H1 receptors of clozapine and olanzapine yet avoids inducing the profound weight gain associated with these drugs; in bipolar patients asenapine showed a mean increase of 1.9kg vs 4.1kg with olanzapine over 12 weeks [McIntyre et al. 2009]. While effects on 5-HT1B and/or 5-HT1A receptors could conceivably contribute, asenapine administration demonstrates a notable lack of effect on 5-HT2C receptor density in rat brain [Tarazi et al. 2010]. This is similar to that of the weaker antagonists risperidone and quetiapine and is in contrast to the down-regulation seen with olanzapine [Tarazi et al. 2002]. The difference could conceivably relate to a 5-HT2C antagonism by asenapine in the absence of the inverse agonism exhibited by olanzapine and clozapine [Herrick-Davis et al. 2000] although this is untested; whatever the mechanism, it does indicate profoundly different pharmacological influences between asenapine and olanzapine on these important receptors involved in the control of body weight."
Good luck.
- ScottSome see things as they are and ask why.
I dream of things that never were and ask why not.The only thing necessary for the triumph of evil is that good men do nothing.
poster:SLS
thread:1116890
URL: http://www.dr-bob.org/babble/20210723/msgs/1116925.html