Antipsychotic Drugs

All antipsychotic drugs decrease dopamine neurotransmission. The conventional neuroleptic drugs block dopamine D2 receptors, leading to a gradual reduction of acute psychotic features and the prevention of relapse; they produce coarse neurological side effects at excessive doses. Clozapine was the first atypical antipsychotic in that it did not produce neurological side effects; it also produced greater therapeutic benefit than did the conventional neuroleptics. The newer atypical antipsychotic drugs add antagonism at type 2 serotonin receptors to D2 antagonism, and produce less neurological side effects; however, some of these drugs produce substantial weight gain, and elevations in lipids and insulin resistance.