Albuterol (ie, salbutamol) is a selective beta-2–adrenoreceptor agonist commonly used in human medicine as a bronchodilator and in the management of premature labor. Although albuterol has been used as a bronchodilator in dogs and cats, use in veterinary medicine is not common.1 High doses of albuterol result in diminished beta-2 selectivity and activation of beta-1 adrenergic receptors, causing cardiovascular stimulation.2 Systemic hypotension in response to albuterol-induced peripheral and coronary vasodilation can also contribute to increased heart rate.3 Hypokalemia may develop due to stimulation of sodium/potassium-ATPase via beta-2 adrenergic receptors.4,5
Clinical signs of toxicosis are based on beta-agonist actions on adrenoreceptors in various organs. Most organs are affected, but the cardiovascular system, musculoskeletal system, and CNS are primarily affected. Clinical signs include tachycardia, tachypnea, lethargy, vomiting, muscle tremors, ataxia, agitation, and polydipsia. Most dogs develop clinical signs within several hours of exposure.
This retrospective study evaluated onset and duration of common clinical signs, treatment, and outcome in 501 dogs with acute, accidental exposure to albuterol. Clinical signs developed in 471 dogs (94%) following albuterol exposure. Tachycardia was the most common clinical sign (404 dogs [80.6%]); median onset and duration were 2.5 and 13.3 hours, respectively. Tachypnea, dullness/lethargy, and vomiting were also common. Blood potassium concentration was measured in 142 dogs, and hypokalemia was reported in 106 dogs (median onset and duration were 2.4 and 13 hours, respectively). Beta-blockers, IV fluids, potassium supplementation, and sedation were the most common treatments. Survival rate among dogs with clinical signs was 99.6%.