[semisynthetic derivative of ergot; it has complex effects on serotonergic systems including antagonism at some peripheral serotonin receptors, both agonist and antagonist actions at central nervous system serotonin receptors, and possibly effects on serotonin turnover; it is a potent hallucinogen and psychotomimetic. ( CSP )] (UMLS (CSP) C0024334) =Organic Chemical; Pharmacologic Substance; Hazardous or Poisonous Substance =ergoline; hallucinogen