What makes each antipsychotic different?

[swanny]

so antipsychotics block dopamine right? well there are about 10 atypicals in total. but what makes each one different to each other? obviously besides the name. i mean the way they work. do they block dopamine in different ways? plz explain?

[Moil]

I believe there are something like 5 different types of dopamine receptor.  So I think which receptors and how they are targeted is one of the differences...oh, and they all have different side effects so if one isn't bearable you can try a different one and hope for nicer side effects.

You should really wait for an answer from one of the more senior members...or even some of the not so senior members as they'll probably have a better idea than I.

[Velvet Elvis]

I'm afraid your initial assumption that all they do is "block dopamine" is somewhat naive.

They are all active on other neurotransmitters at various receptor sites and they also vary in how and where they block dopamine.

You can go to RXlist and look up a med and it will tell you exactly how each one works under the pharmacology section. For example, Zyprexia:

Mechanism of Action

The mechanism of action of olanzapine, as with other drugs having efficacy in schizophrenia, is unknown. However, it has been proposed that this drug's efficacy in schizophrenia is mediated through a combination of dopamine and serotonin type 2 (5HT2) antagonism. The mechanism of action of olanzapine in the treatment of acute manic or mixed episodes associated with bipolar I disorder is unknown.

Pharmacodynamics

Olanzapine binds with high affinity to the following receptors: serotonin 5HT2A/2C, 5HT6 (Ki=4, 11, and 5 nM, respectively), dopamine D1-4 (Ki=11-31 nM), histamine H1 (Ki=7 nM), and adrenergic α1 receptors (Ki=19 nM). Olanzapine is an antagonist with moderate affinity binding for serotonin 5HT3 (Ki=57 nM) and muscarinic M1-5 (Ki=73, 96, 132, 32, and 48 nM, respectively). Olanzapine binds weakly to GABAA, BZD, and β-adrenergic receptors (Ki > 10 μM).

Antagonism at receptors other than dopamine and 5HT2 may explain some of the other therapeutic and side effects of olanzapine. Olanzapine's antagonism of muscarinic M1-5 receptors may explain its anticholinergic-like effects. Olanzapine's antagonism of histamine H1 receptors may explain the somnolence observed with this drug. Olanzapine's antagonism of adrenergic α1 receptors may explain the orthostatic hypotension observed with this drug.

http://www.rxlist.com/zyprexa-drug.htm

As you can see the mechanism of action for Zyprexa, like all the AAPs, is quite complicated and intricate. There are many points of variation between all of them. They don't just work on Dopamine, but on norepenephrine, serotonin among many other mechanisms of action.

You can find links to how various drugs work here: http://www.neurotransmitter.net/drug_reference.html

[Moil]

See what did I tell you.  Someone who knows something.

[Velvet Elvis]

And yes, there are 5 different DA receptor types with many subtypes below that. Most APs target the D₂ family.