Antipsychotic drugs classification

Meltzer HY, Matsubara S, Lee LC. Classification of typical and atypical antipsychotic drugs on the basis of dopamine D D2 and serotonin2 pKi values. J Pharmacol Exp Ther 1989 25 238-246. 

Thus the most important distinction in modern-day classification of antipsychotic drugs is between... 

Antipsychotic drugs A major classification of drugs, most of which are dopamine receptor antagonists (with the exception of the newer antipsychotic medications), and are used to address disturbances in affect and mood such as psychosis, delusions, and psychotic depression. 

A. Classification The major chemical subgroups of antipsychotic drugs are the phenothiazines (eg, chlorpromazine, thioridazine, fluphenazine) the thioxanthenes (eg, thiothixene) and the butyrophenones (eg, halopeiidol). 

Because of multiple receptor actions, which occur at different concentrations, different neuroleptics have different action profiles. There are many classifications for neuroleptic drugs, the least useful of which is probably based on their chemical structure. Other classifications include linear classifications based on the propensity to cause EPS, or multidimensional ones such as the Liege star which combines information on three positive effects (anti-autistic, antiproductive, antipsychotic), and three negative (hypotensive, extrapyramidal, sedative). In a general way, the more sedative neuroleptics such as levomepromazine, used more to treat acute agitation states, cause more hypotension related to alpha blockade, whereas those that act best on delirium (productive states) such as haloperidol tend to cause more EPS. 

No recognised classification system exists for atypical antipsychotics.Tentative terms based on receptor binding profiles have been applied to certain drug groupings.for example broad spectrum atypicals for clozapine, olanzapine and quetiapine. whilst risperidone and ziprasidone have been described as high affinity serotonin-dopamine antagonists . 

Numerous other drugs followed (see table 10) and these typical antipsychotics became one of the five most common classifications of medication for treating mental health disorders. 

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