Effect of Terbutaline on Human Eustachian Tube Function

Terbutaline, a beta2-adrenoceptor agonist, was administered subcutaneously to 10 healthy adult subjects. The pressure opening level (Pol) of the Eustachian tube (ET) and the remaining middle ear pressure when the ET closed (Pel) after passive equilibration were measured as well as parameters for active tubal function. A quantitative impedance method in combination with a pressure chamber was used. Pol was reduced by 0.29 ± 0.10 (-7.3%) kPa 90 min after injection of terbutaline 5 µg/kg body weight. There was also a decrease in Pel, 0.17 ± 0.06 kPa (-14.0%). No such decrease was seen after saline solution injected subcutaneously. It is suggested that terbutaline facilitates the ET opening by stimulating the secretion of surface tension lowering substances.