Functional Changes of Orexinergic Reaction to Psychoactive Substances

It is becoming increasingly apparent the importance of the central nervous system (CNS) as the major contributor to the regulation of systemic metabolism. Antipsychotic drugs are used often to treat several psychiatric disorders, including schizophrenia and bipolar disorder However, antipsychotic drugs prescription, particularly the second-generation ones (SGAs), such as clozapine and olanzapine, is related to a considerable weight gain which usually leads to obesity. The aim of this paper is to assess the influence of orexin A on sympathetic and hyperthermic reactions to several neuroleptic drugs. Orexin A is a neuropeptide which effects both body temperature and food intake by increasing sympathetic activity. Orexin A-mediated hyperthermia is reduced by haloperidol and is blocked by clozapine and olanzapine. Orexin A-mediated body temperature elevation is increased by risperidone. These hyperthermic effects are delayed by quietapine. In this paper, it is discussed the orexinergic pathway activation by neuroleptic drugs and its influence on human therapeutic strategies. With the aim to determine that neuroleptic drugs mediate body temperature control through to the orexinergic system, we summarized our previously published data. Psychiatric disorders increase the risk of developing metabolic disorders (e.g., weight gain, increased blood pressure, and glucose or lipid levels). Therefore, the choice of antipsychotic drug to be prescribed, based on the relevant risks and benefits of each individual drug, has an essential role in human health prevention.