Antipsychotics

Antipsychotics are a group of drugs used in the management of schizophrenia and other forms of psychosis, mania and agitation. They are usually divided into typical and atypical antipsychotics. The atypical antipsychotics were developed due to the problematic extrapyramidal side-effects which are associated with the first generation of typical antipsychotics.

	Typical antipsychotics	Atypical antipsychotics
Mechanism of action	Dopamine D2 receptor antagonists, blocking dopaminergic transmission in the mesolimbic pathways	Act on a variety of receptors (D2, D3, D4, 5-HT)
Adverse effects	Extrapyramidal side-effects and hyperprolactinaemia common	Extrapyramidal side-effects and hyperprolactinaemia less common
Metabolic effects eg weight gain
Examples	Haloperidol
Chlorpromazine	Clozapine
Risperidone
Olanzapine

Examples of atypical antipsychotics

clozapine
olanzapine: higher risk of dyslipidemia and obesity
risperidone
quetiapine
amisulpride
aripiprazole: generally good side-effect profile, particularly for prolactin elevation

Adverse effects of atypical antipsychotics

weight gain
clozapine is associated with agranulocytosis (see below)
hyperprolactinaemia