First generation antipsychotics typicals

Current antipsychotics used to treat patients are divided into two classes the first generation antipsychotics (FGA) or typicals (e.g., chlorproma-zine, haloperidol, thioridazine, and loxapine) and the second generation antipsychotics (SGA) or atypicals (i.e., clozapine, olanzapine, quetiapine, risperidone, aripiprazole, ziprasidone, and asenapine). 

The first generation antipsychotics, now known as typical drugs, were all D2 receptor blockers and, as such, very likely to produce Parkinsonian side effects. Because antipsychotic potency was associated with D2 receptor affinity, it was assumed that dopamine overactivity was the essential defect in schizophrenia and that a direct dopamine blockade was the definitive route to treatment. But these drugs affected both the target dopamine pathways of the mesolimbic projection and the uninvolved nigrostriatal projection. Unfortunately, that meant that movement disorders were the price that had to be paid for antipsychosis. 

Typical (first-generation) antipsychotic drugs - mechanism of action... 

These are dopamine antagonists. First generation antipsychotics ( GAs/typicals) are the older drugs, while second generation antipsychotics SGAs/atypicals) are the newer ones. It s a fairly arbitrary distinction, and although side effects differ, they overlap between the two groups. 

TABLE 34-6. First-Generation (Typical) Antipsychotic Dosing of Decanoate Preparations... 

TABLE 34-7. Side Effects of First-Generation (Typical) Antipsychotics... 

First-generation (typical) antipsychotics include amisulpride, chlorpromazine, fluphenazine, haloperidol, promethazine, promazine, trifluoperazine... 

The CATIE project will evaluate the clinical effectiveness of atypical antipsychotics in the treatment of schizophrenia and of Alzheimer s disease. Although antipsychotics were first introduced for the treatment of schizophrenia, they are now used for many other disorders. It is unclear how effective they are and, most important, in view of their rather high cost, how favorably they compare to the first generation of antipsychotics, all of which are available in generic (and thus much less expensive) forms. The CATIE (Clinical Antipsychotic Trials in Intervention Effectiveness) study has specific aims, including the determination of long-term effectiveness and tolerability of the atypical antipsychotics, compared to each and to a typical or classic antipsychotic. At this... 

The primary treatment for schizophrenia involves use of antipsychotic medications. These are classified as typical or first generation, and atypical. The atypical antipsycho tics differ from the typical in having relatively less extrapyramidal side effects, such as rigidity, dystonia (muscle spasm), akathi-sia (motor restlessness), and pseudo-Parkinsonian symptoms. 

First-generation ( typical ) antipsychotic drugs - phenothiazines... 

---