Butyrophenones are sedative drugs, which have a potent anti-emetic effect.

Mechanism of Action

Butyrophenones antagonise dopamine transmission in the CNS.

Side Effects and Contraindications

Adverse effects in the CNS may occur, for example hallucinations and agitation have been reported in man. Vasodilation and hypotension also result from administration.

Drugs in this Group

Azaperone

Azaperone is marketed under the trade name of Stresnil. It modifies behaviour and gives dose-related sedation. It is used in pigs, for example against aggresssion and transport stress, to aid obstetrical intervention and as a premedicant. Intramuscular administration is preferred, with a 20 minute onset time (this is 5 mins if given i/v). The effects last 2-6 hours, and the drug potentiates anaesthetic agents.