A 19-year-old man is brought to the physician’s office by his very concerned mother. He has been kicked out of the dormitory at college for his “bizarre” behavior. He has accused several fellow students and professors of spying on him for the CIA. He stopped attending his classes and spends all of his time watching TV because the announcers are sending him secret messages on how to save the world. He has stopped bathing and will only change his clothes once a week. In your office you find him to be disheveled, quiet, and unemotional. The only spontaneous statement he makes is when he asks why his mother brought him to the office of “another government spy.” His physical examination and blood tests are normal. A drug screen is negative. You diagnose him with acute psychosis secondary to schizophrenia, admit him to the psychiatric unit of the hospital, and start him on haloperidol.
1) What is the mechanism of therapeutic action of haloperidol?
2) What mediates the extrapyramidal side effects (EPSs) of the antipsychotic agents?
3) Which autonomic nervous system receptors are antagonized by antipsychotic agents?