Psycho-Babble Medication Thread 117396

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Antipsychotic with lowest incidence of TD?

Posted by cybercafe on August 22, 2002, at 13:02:36

Okay i've been searching the web, but I can't seem to find which antipsychotic (besides clozapine) has the lowest incidence of TD? and EPS?

anyone know?

Re: Antipsychotic with lowest incidence of TD? » cybercafe

Posted by Ritch on August 22, 2002, at 23:56:45

In reply to Antipsychotic with lowest incidence of TD?, posted by cybercafe on August 22, 2002, at 13:02:36

>
> Okay i've been searching the web, but I can't seem to find which antipsychotic (besides clozapine) has the lowest incidence of TD? and EPS?
>
> anyone know?

Hi Cyber,

It depends on the history of the medicine for a great part, because TD is a historical phenomenon (over a relatively large span of time). Of the "conventional" phenothiazine antipyschotics, Mellaril (thioridazine), probably has the least potential for TD *based on* its lower level of EPS symptoms compared to chlorpromazine and trifluoperazine (and others). Haldol (haloperidol) is newer, but is notorious for TD, however a very effective acute treatment for psychosis. Of the newer "atypicals" (besides clozapine) you have only relative EPS occurence to guide you as a possible indicator for possible future TD (not enough time has passed to make a good judgement). I have had personal experience with Thorazine, Stelazine, Compazine, Phenergan, Haldol, Mellaril, Risperdal, and Seroquel. Of those, Stelazine, Haldol, and Risperdal (in rank) were the worst for me regarding EPS symptoms. They all just happen to be higher *potency* antipychotics (response/mg-dosage). The lower the potency, it seems, the less adverse effects-EPS-wise (despite a relatively higher dosage of the lower potency agent). This is highly personalized, so take it with a grain of salt.

Mitch

Re: Antipsychotic with lowest incidence of TD?

Posted by cybercafe on August 23, 2002, at 1:13:11

In reply to Re: Antipsychotic with lowest incidence of TD? » cybercafe, posted by Ritch on August 22, 2002, at 23:56:45

>They all just happen to be higher *potency* antipychotics (response/mg-dosage). The lower the potency, it seems, the less adverse effects-EPS-wise (despite a relatively higher dosage of the lower potency agent). This is highly personalized, so take it with a grain of salt.

Okay here is where it gets tricky. Because of serotonin 5HT2A antagonism, atypicals have a lower incidence of EPS. They "hide" what is going on in the striatum (extrapyrimidal motor area). Normally I think a lower potency drug like seroquel/quetipane (dosage around 100 mg) would have lower eps than a higher potency drug like olanzapine/zyprexa, however! Zyprexa has a much higher potency for the 5HT2A receptor, which means it "hides" the EPS symptoms better. So... what i am wondering is... when you stop taking the drug where long term effects on the dopamine system would cause TD, do long term effects on the serotonin system still compensate?
i can't answer this question, because i do not know the mechanism responsible for TD...
that's why i can only go by anecdotal/experimental data

thanks for your input dude ;)

Re: Antipsychotic with lowest incidence of TD? » cybercafe

Posted by Ritch on August 23, 2002, at 8:57:49

In reply to Re: Antipsychotic with lowest incidence of TD?, posted by cybercafe on August 23, 2002, at 1:13:11

> >They all just happen to be higher *potency* antipychotics (response/mg-dosage). The lower the potency, it seems, the less adverse effects-EPS-wise (despite a relatively higher dosage of the lower potency agent). This is highly personalized, so take it with a grain of salt.
>
> Okay here is where it gets tricky. Because of serotonin 5HT2A antagonism, atypicals have a lower incidence of EPS. They "hide" what is going on in the striatum (extrapyrimidal motor area). Normally I think a lower potency drug like seroquel/quetipane (dosage around 100 mg) would have lower eps than a higher potency drug like olanzapine/zyprexa, however! Zyprexa has a much higher potency for the 5HT2A receptor, which means it "hides" the EPS symptoms better. So... what i am wondering is... when you stop taking the drug where long term effects on the dopamine system would cause TD, do long term effects on the serotonin system still compensate?
> i can't answer this question, because i do not know the mechanism responsible for TD...
> that's why i can only go by anecdotal/experimental data
>
> thanks for your input dude ;)

Cyber,

There is a lot of debate about whether the serotonergic activity of the newer meds has anything to do with less risk of TD or not. Cam W. mentioned that the relatively reversible binding qualities of the newer meds to DA receptors is more predictive of lesser risk of TD, and that's the only reason. He was supposed to post some info about it, but hasn't yet.

Mitch

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