Posted by med_empowered on February 9, 2007, at 12:51:22
In reply to Difference between typical / atypical APs?, posted by Klavot on February 9, 2007, at 12:04:36
OK...here's the thing: there are actually alot of differences amongst all the "typical" APs. For instance: Mellaril is slightly atypical and causes less EPS than a lot of other meds. Haldol is super-high potency and causes lots of problems; Loxapine and Moban are both somewhat atypical, and some drugs that aren't usually considered neuroleptics (surmontil, asendin) can be used in some cases of psychosis. Its all very confusing.
Generally speaking, atypical antipsychotics: have significant serotonin antagonism, don't cause marked EPS as effective dosages, carry a lower risk of TD than older meds, and may be somewhat more effective on mood and/or anxiety symptoms than older meds. But...like I said..there's a lot of variation; low-to-mid dose perphenazine, for instance, performed about as well as Zyprexa in the CATIE study. Haldol+benztropine did about as well as zyprexa in another study. One common characteristic seems to be less D2 blockade at common dosage and a lot of them only block D2 for a while, whereas older drugs tend to stick around in the receptor 24/7. Abilify is an exception; at the higher end of the dosages, it can block 90% or more D2 receptors without the EPS you'd expect, b/c of its partial agonism. But then again, Abilify also causes marked akathisia, so time will tell just how tolerable and wonderful it turns out to be.
It could just be that the serotonin activity plus built-in anticholinergic action that some have (zyprexa, seroquel) dampens down EPS, in the same sense that adding BuSpar and benztropine to, say, a low-dose of Haldol might also make it more tolerable.
poster:med_empowered
thread:731385
URL: http://www.dr-bob.org/babble/20070207/msgs/731397.html