PS268 Chapter Notes - Chapter 8: Atypical Antipsychotic, Typical Antipsychotic, Dyskinesia
Document Summary
Virtually all of the phenothiazines and other typical antipsychotics produce pseudoparkinsonism. Because parkinson"s disease is caused by loss of dopamine neurons in nigrostriatal dopamine pathway, scientists focused on ability of antipsychotic drugs to block dopamine receptors. The initial effect of antipsychotic drugs is to block d2 dopamine receptors. This effect occurs with first dose, but antipsychotic effect is not seen for 10-14 days (lag period) thus ultimate mechanism of antipsychotic action is some response of the nervous system to repeated administration of dopamine antagonists. Clozapine differs from other antipsychotics bc it produces much less pseudoparkinsonism and patients who failed to improve with other drugs showed improvement with clozapine. However clozpine has risk of producing a deadly suppression of white blood cell production causing it to be withdrawn from market, and then available again as long as patients do periodic blood samples. Clozapine"s unique properties related to ability to block dopamine d2 and serotonin.
