Serum potassium levels during and after terbutaline.

The intravenous infusion of terbutaline is associated with decreased levels of serum potassium. The duration of this hypokalemia has not been reported. Therefore, serum potassium levels were measured in dogs before during and for 3 hours after a 2-hour intravenous infusion of 0.5 micrograms/kg/min of terbutaline. Serum potassium levels decreased significantly during the infusion and returned to near preinfusion levels within 3 hours after the infusion was stopped. The mechanism for the decrease in the serum potassium is most likely a shift of the potassium ion from the extracellular space to the intracellular space.