Extrapyramidal Symptoms in Patients Treated with Antipsychotic Drugs

Extrapyramidal symptoms are adverse effects of second-generation antipsychotic drugs which are generally used to treat schizophrenia and schizoaffective disorder. These adverse effects are due to the D2 receptor blockade. Neurotransmitter and neuropeptide alterations in the mesolimbic system and in the extrapyramidal system and the derived neural networks are described. M4 antagonists, GABAA agonists or NMDA antagonists can be used to treat the extrapyramidal symptoms because they improve the dopaminergic-cholinergic neurotransmitter imbalance in this neural system. Recently developed antipsychotic drugs such as aripiprazole and cariprazine cause less often and, to a lesser extent, extrapyramidal symptoms because they exert a partial agonism at the D2 receptor.