Abstract
Haloperidol was synthesized on the 11th of February 1958 at the Janssen Laboratories, in Belgium. Soon after its synthesis and animal studies, which suggested to Paul Janssen and his colleagues that this butyrophenone drug would be of great interest as its action was similar but much more powerful than that of chlorpromazine, haloperidol was administered to humans at the Liege hospital. The subsequent clinical studies confirmed that this new drug was particularly active against delusions and hallucinations. The introduction of haloperidol in the United States of America was difficult for clinical and legal reasons. For many years, haloperidol had been widely used in western countries, until the introduction of “new antipsychotics.”