n. a high-potency antipsychotic of the butyrophenone class, in use in Europe in the 1950s and in the United States from 1965. Haloperidol and other high-potency antipsychotics were preferred over lower potency phenothiazines because of their lack of cardiovascular and anticholinergic effects; however, they were associated more with extrapyramidal symptoms and tardive dyskinesia than lower potency agents. The increased safety profile of the second-generation atypical antipsychotics has led to a decline in use of haloperidol, although it is still used individually and in conjunction with newer agents. Some argue that few differences exist between the newer agents and haloperidol if the latter is used in much lower doses than has been customary. U.S. trade name: Haldol.