Comparative heart rate effects of oral administration of bitolterol, terbutaline and trimetoquinol in unanesthetized dogs.

Effect of a clinical dose of bitolterol, a new oral bronchodilator via adrenergic beta-receptor, on heart rate was compared with those of terbutaline and trimetoquinol in unanesthetized dogs. Oral administration of bitolterol, terbutaline and trimetoquinol increased the heart rate. The heart rate effect of bitolterol was significantly weaker than those of terbutaline and trimetoquinol.