molecular entity droperidol 1-{1-[4-(4-fluorophenyl)-4-oxobutyl]-1,2,3,6-tetrahydropyridin-4-yl}-1,3-dihydro-2H-benzimidazol-2-one An organofluorine compound that is haloperidol in which the hydroxy group has been eliminated with the introduction of a double bond in the piperidine ring, and the 4-chlorophenyl group has been replaced by a benzimidazol-2-on-1-yl group. It is used in the management of chemotherapy-induced nausea and vomiting, and in conjunction with an opioid analgesic such as fentanyl to maintain the patient in a calm state of neuroleptanalgesia with indifference to surroundings but still able to cooperate with the surgeon.