Acepromazine is a phenothiazine antipsychotic, analog of chlorpromazine , and a dopamine receptor antagonist.1 It also binds to muscarinic receptors in rat brain (IC50 = 350 nM) and inhibits contractions of guinea pig ileum induced by acetylcholine .2 Acepromazine inhibits morphine-induced vomiting in dogs.3 It also inhibits development of a conditioned avoidance response, unconditioned escape response, and catalepsy in rats (ED50s = 0.98, 3.1, and 17 mg/kg, respectively).4 Formulations containing acepromazine have been used as tranquilizers and anesthetics premedicant in small and large animal veterinary care.
References
1. Monteiro, E.R., Teixeira Neto, F.J., Castro, V.B., et al. Effects of acepromazine on the cardiovascular actions of dopamine in anesthetized dogs. Vet. Anaesth. Analg. 34(5), 312-321 (2007).
2. Fjalland, B., Christensen, A.V., and Hyttel, J. Peripheral and central muscarinic receptor affinity of psychotropic drugs. Naunyn. Schmiedebergs. Arch. Pharmacol. 301(1), 5-9 (1977).
3. Koh, R.B., Isaza, N., Xie, H., et al. Effects of maropitant, acepromazine, and electroacupuncture on vomiting associated with administration of morphine in dogs. J. Am. Vet. Med. Assoc. 244(7), 820-829 (2014).
4. J., A. Pharmacological specificity of conditioned avoidance response inhibition in rats: Inhibition by neuroleptics and correlation to dopamine receptor blockade. Acta. Pharmacol. Toxicol. (Copenh). 51(4), 321-329 (1982).