Acepromazine Interactions

Acepromazine is a common tranquilizer prescribed for dogs to prepare them for anesthesia or to lessen anxiety associated with thunderstorms. It is also thought to be useful for pets who are traveling, as it not only decreases anxiety and nervousness but also has anti-emetic properties that can help combat motion sickness. Acepromazine also prevents muscle spasms, decreases body temperature and decreases itching from skin rashes. It is a mainstay of the veterinary hospital, and considered safe in most circumstances, but there is always a potential for adverse effects caused by interactions with other medications.

  1. About Acepromazine

    • Acepromazine is a sedative derived from phenothiazine, and is closely related to thorazine. Although the exact mechanism is unknown, it is thought to work by blocking dopamine receptors in the brain. This prevents the brain cells from communicating, resulting in the depression of the central nervous system and producing a tranquilizing effect. As such, it is classified as a neuroleptic, meaning it changes behavior by altering chemical levels in the brain. Acepromazine is not a pain reliever, but it does increase blood flow, which can stimulate healing and reduce the perception of pain and itching.

    Beneficial Interactions

    • Vets commonly use acepromazine as a pre-anesthetic agent to provide a smoother transition into and out of general anesthesia. This results in a reduced fear response to the unfamiliar surroundings of the veterinary hospital, and keeps the dog calm for surgical preparatory activities such as placing the IV catheter. Also, because acepromazine increases blood flow, any anesthetic agent injected intravenously will speed through the system that much more quickly and the dog will “go under” much more smoothly. The use of acepromazine with general anesthetic provides a deeper state of sedation while using a lesser amount of either drug.

    Harmful Interactions

    • Using acepromazine requires caution in dogs taking quinidine, a heart medication. Acepromazine can lower the blood pressure by reducing nervous control of blood vessels, and can lead to an abrupt change in heart rate, which can trigger adverse reactions in dogs with heart problems. Similar effects occur when using it with epinephrine and propanolol as well. Antacids and anti-diarrheal medications can reduce the absorption of acepromazine, and sufficient sedation may not be achieved. Dogs that are being treated with organophosphate dewormers or flea control can experience major ill effects if given acepromazine. Organophosphates tend to congregate and affect the areas where muscles and nerves meet; because acepromazine slows the nervous response, the typical nerve signal does not go through the muscle, resulting in serious muscle impairment.

    Side Effects

    • Some dogs respond to acepromazine by becoming excited or aggressive instead of sedated, and the drug can trigger seizures in epileptic dogs. Acepromazine also lowers the body temperature, so the dog must be kept warm. Acepromazine is considered safe, but some pet owners report an increased sensitivity to the drug in boxer dogs.

    Alternatives

    • Diazepam or alprazolam can be substitutes for acepromazine. In fact, many vets are turning to alprazolam for use during thunderstorms because it sedates as well as acepromazine, but does not increase the dog’s perception of loud noises like acepromazine does.