see also:

• sympathomimetics
• dopamine
• dopamine receptors

• dopamine receptors in the brain and autonomic ganglia are vital for a wide range of neurologic functions and are involved in the extrapyramidal movement control system, pleasure reward systems, modulation of autonomic system and prolactin secretion
• dopamine D1 receptors also have an important role in increasing blood flow to the GIT and kidneys
• most medications that block dopamine receptors also act on other receptor systems, examples include:
  • anti-emetics such as metoclopramide (Maxolon)
  • phenothiazines including prochlorperazine (Stemetil) and chlorpromazine (Largactil)
  • butyrophenone type antipsychotic agents including haloperidol and droperidol (Droleptan)
  • other anti-psychotic medications
  • tricyclic antidepressants
• these agents may cause:
  • extrapyramidal reactions such as oculogyric crisis, dystonic reactions, akathisia
  • tardive dyskinesia
  • parkinsonism
  • neuroleptic malignant syndrome (NMS)
  • hyperprolactinaemia and thus amenorrhoea
  • anhedonia
  • dysphoria
  • irritability