Acepromazine

Acepromazine or acetylpromazine (more commonly known as ACP, Ace, or by the trade names Atravet or Acezine 2, number depending on mg/ml dose) is a phenothiazine derivative antipsychotic drug. It was first used in humans in the 1950s, but is now little used in humans (the closely related analogue, chlorpromazine, is still used as an antipsychotic in humans). Acepromazine is frequently used in animals as a sedative and antiemetic. Its principal value is as a chemical restraint in hyper or fractious animals. However it does not relieve anxiety and some believe it may make anxiety worse in the long run if used in an anxious animal (for example, thunderstorm phobias). The standard pharmaceutical preparation, acepromazine maleate, is used in veterinary medicine in dogs, and cats. It is used widely in horses as a pre-anaesthetic sedative and has been shown to reduce anaesthesia related death. However, it should be used with caution (but is not absolutely contraindicated) in stallions due to the risk of paraphimosis and persistent priapism. Its potential for cardiac effects, namely hypotension due to peripheral vasodilation, can be profound and as such is not recommended for use in geriatric or debilitated animals, especially dogs. In these cases it is most often substituted with midazolam or diazepam and left out of the preanesthetic medication altogether.