RESEARCH PAPER| Volume 47, ISSUE 4, P447-453, July 2020

Hemodynamic, respiratory and sedative effects of progressively increasing doses of acepromazine in conscious dogs

Published:March 23, 2020DOI:



      To evaluate the effects of progressively increasing doses of acepromazine on cardiopulmonary variables and sedation in conscious dogs.

      Study design

      Prospective, experimental study.


      A group of six healthy, adult, mixed-breed dogs weighing 16.5 ± 5.0 kg (mean ± standard deviation).


      Dogs were instrumented with thermodilution and arterial catheters for evaluation of hemodynamics and arterial blood gases. On a single occasion, acepromazine was administered intravenously to each dog at 10, 15, 25 and 50 μg kg–1 at 20 minute intervals, resulting in cumulative acepromazine doses of 10 μg kg–1 (ACP10), 25 μg kg–1 (ACP25), 50 μg kg–1 (ACP50) and 100 μg kg–1 (ACP100). Hemodynamic data and sedation scores were recorded before (baseline) and 20 minutes after each acepromazine dose.


      Compared with baseline, all acepromazine doses significantly decreased stroke index (SI), mean arterial pressure (MAP) and arterial oxygen content (CaO2) with maximum decreases of 16%, 17% and 21%, respectively. Cardiac index (CI) decreased by up to 19% but not significantly. Decreases of 26–38% were recorded for oxygen delivery index (DO2I), with significant differences for ACP50 and ACP100. Systemic vascular resistance index (SVRI) and heart rate did not change significantly. No significant difference was found among acepromazine doses for hemodynamic data. After ACP10, mild sedation was observed in five/six dogs and moderate sedation in one/six dogs, whereas after ACP25, ACP50 and ACP100, moderate sedation was observed in five/six or six/six dogs.

      Conclusions and clinical relevance

      In conscious dogs, acepromazine decreased MAP, SI, CaO2 and DO2I, but no significant dose effect was detected. SVRI was not significantly changed, suggesting that the reduction in MAP resulted from decreased CI. The ACP25, ACP50 and ACP100 doses resulted in moderate sedation in most dogs; ACP10 resulted in only mild sedation.


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        • Coulter D.B.
        • Whelan S.C.
        • Wilson R.C.
        • Goetsch D.D.
        Determination of blood pressure by indirect methods in dogs given acetylpromazine maleate.
        Cornell Vet. 1981; 71: 75-84
        • Dyson D.
        • Pettifer G.
        Evaluation of the arrhythmogenicity of a low dose of acepromazine: comparison with xylazine.
        Can J Vet Res. 1997; 61: 241-245
        • Hall L.W.
        Principles of sedation, analgesia and premedication.
        in: Hall L.W. Clarke K.W. Trim C.M. Veterinary Anaesthesia. 10th edn. WB Saunders, UK2001: 75-112
        • Haskins S.
        • Pascoe P.J.
        • Ilkiw J.E.
        • et al.
        Reference cardiopulmonary values in normal dogs.
        Comp Med. 2005; 55: 156-161
        • Heard D.J.
        • Webb A.I.
        • Daniels R.T.
        Effects of acepromazine on the anesthetic requirement of halothane in the dog.
        Am J Vet Res. 1986; 47: 2113-2115
        • Jensen B.C.
        • O’Connell T.D.
        • Simpson P.C.
        Alpha-1-adrenergic receptors in heart failure: the adaptive arm of the cardiac response to chronic catecholamine stimulation.
        J Cardiovasc Pharmacol. 2014; 63: 291-301
        • Lang S.M.
        • Eglen R.M.
        • Henry A.C.
        Acetylpromazine administration: its effect on canine haematology.
        Vet Rec. 1979; 105: 397-398
        • Ludders J.W.
        • Reitan J.A.
        • Martucci R.
        • et al.
        Blood pressure response to phenylephrine infusion in halothane-anesthetized dogs given acetylpromazine maleate.
        Am J Vet Res. 1983; 44: 996-999
        • Monteiro E.R.
        • Figueroa C.D.N.
        • Choma J.C.
        • et al.
        Effects of methadone, alone or in combination with acepromazine or xylazine, on sedation and physiologic values in dogs.
        Vet Anaesth Analg. 2008; 35: 519-527
        • Monteiro E.R.
        • Rodrigues Junior A.
        • Assis H.M.
        • et al.
        Comparative study on the sedative effects of morphine, methadone, butorphanol or tramadol, in combination with acepromazine, in dogs.
        Vet Anaesth Analg. 2009; 36: 25-33
        • Popovic N.A.
        • Mullane J.F.
        • Yhap E.O.
        Effects of acetylpromazine maleate on certain cardiorespiratory responses in dogs.
        Am J Vet Res. 1972; 33: 1819-1824
        • Shannon R.
        • Chaudhry M.
        Effect of alpha1-adrenergic receptors in cardiac pathophysiology.
        Am Heart J. 2006; 152: 842-850
        • Stepien R.L.
        • Bonagura J.D.
        • Bednarski R.M.
        • Muir III, W.W.
        Cardiorespiratory effects of acepromazine maleate and buprenorphine hydrochloride in clinically normal dogs.
        Am J Vet Res. 1995; 56: 78-84
        • Turner D.M.
        • Ilkiw J.E.
        • Rose R.J.
        • Warren J.M.
        Respiratory and cardiovascular effects of five drugs used as sedatives in the dog.
        Aust Vet J. 1974; 50: 260-265
        • Valverde A.
        • Cantwell S.
        • Hernández J.
        • Brotherson C.
        Effects of acepromazine on the incidence of vomiting associated with opioid administration in dogs.
        Vet Anaesth Analg. 2004; 31: 40-45
        • Webb A.I.
        • O`Brien J.M.
        The effect of acepromazine maleate on the anesthetic potency of halothane and isoflurane.
        J Am Anim Hosp Assoc. 1988; 24: 609-613