The effects of salbutamol and terbutaline on physiological tremor, bronchial tone and heart rate.

1 The effects of oral doses of the bronchodilator drugs, salbutamol (4 and 8 mg) and terbutaline (5 and 10 mg), on physiological tremor, bronchial tone, heart rate and blood pressure were studied in six normal subjects. 2 Both drugs produced a significant increase in physiological tremor, compared with placebo. Terbutaline, but not salbutamol, produced a dose related response. No significant differences were observed between drugs. 3 Terbutaline (5 and 10 mg) and salbutamol (8 mg) produced a significant bronchodilatation compared with placebo. Dose related responses were obtained with both drugs, although this reached significance only with terbutaline. 4 Both doses of each drug produced a tachycardia, although this was only statistically significant with the high doses. 5 No significant change in blood pressure was observed with either drug. 6 Peak effects of salbutamol occurred between 1 and 3 h and terbutaline between 1 and 4 hours. Both drugs were still active at 6 hours.