Effect of inhaled albuterol on whole blood potassium concentrations in dogs

Abstract

Background: Albuterol by inhalation (IH) is a common treatment for hyperkalemia in humans but its effect on blood potassium concentrations in dogs is unknown.

Objective: Determine whether albuterol (IH) decreases blood potassium concentrations in healthy normokalemic dogs and if effects are dose-dependent.

Animals: Ten healthy dogs.

Methods: Prospective, crossover experimental study. Albuterol sulfate was administered at a low-dose (90 μg) in phase I and, 7 days later, high-dose (450 μg) in phase II. Blood potassium and glucose concentrations (measured via blood gas analyzer) and heart rates were obtained at baseline and then 3, 5, 10, 15, 30, 60, 90, 120, 180, and 360 minutes after inhaler actuation.

Results: Blood potassium concentrations decreased rapidly after albuterol delivery with a significant reduction compared to baseline within 30 minutes in both phases (P = .05). The potassium nadir concentration of phase I occurred at 60 minutes (mean, SD; 4.07 mmol/L, 0.4) and was significantly decreased from baseline, (4.30 mmol/L, 0.3; t(9) = 2.40, P = .04). The potassium nadir concentration of phase II occurred at 30 minutes (mean, SD; 3.96 mmol/L, 0.39) and was also significantly decreased from baseline, (4.33 mmol/L, 0.4; t(9) = 2.22, P = .05). The potassium nadir concentration decreased by 0.1 mmol/L for each 10 μg/kg increase in dose of albuterol (P = .01). Five dogs had ≥1 hyperglycemic measurement (ie, >112 mg/dL). No median heart rate was tachycardic nor was any mean blood glucose concentration hyperglycemic at any time point.

Conclusion and clinical importance: Albuterol IH decreases blood potassium concentrations in a dose-dependent manner without clinically meaningful alterations to heart rate or blood glucose concentrations in healthy dogs. The mean decrease in potassium concentration at the high-dose of albuterol was modest (0.38 mmol/L).

Keywords: blood gas; electrolytes; hyperkalemia; β2-agonist.