From Dog

Phenoxybenzamine is a non-selective α-adrenergic receptor antagonist used for treatment of canine ventricular tachycardia[1] and hypertension associated with pheochromocytoma[2].

Its pharmacological effects are achieved by reducing the vasoconstriction caused by epinephrine (adrenaline) and norepinephrine.

Phenoxybenzamine forms a permanent covalent bond with adrenergic receptors.

This drug also reduces smooth muscle tension and has been utilized for control of urethral constriction associated with urolithiasis[3].

Recommended dose rate in dogs is 0.6 mg/kg orally twice daily.


  1. Ginn JA et al (2012) Systemic Hypertension and Hypertensive Retinopathy Following PPA Overdose in a Dog. J Am Anim Hosp Assoc Nov 12
  2. Herrera MA et al (2008) Predictive factors and the effect of phenoxybenzamine on outcome in dogs undergoing adrenalectomy for pheochromocytoma. J Vet Intern Med 22(6):1333-1339
  3. Fischer JR et al (2012) Urethral pressure profile and hemodynamic effects of phenoxybenzamine and prazosin in non-sedated male beagle dogs. Can J Vet Res 67(1):30-38