Theophylline-salbutamol interaction: bronchodilator response to salbutamol at maximally effective plasma theophylline concentrations.
1 The effect of inhaled salbutamol following a maximally effective dose of theophylline given by intravenous infusion was determined in 12 patients with chronic bronchitis. 2 An initial single intravenous dose study was performed to estimate each patient's theophylline kinetics and to identify those patients who would respond to theophylline. 3 Pulmonary function was assessed at hourly intervals during four to five incremental steady state theophylline infusions over the concentration range 5-25 mg/l. 4 Inhaled salbutamol (400 micrograms) was administered after the maximum effect from theophylline had been achieved or when theophylline concentrations reached 25 mg/l without maximum effect: pulmonary function was again assessed. 5 Ten patients achieved a further significant improvement in pulmonary function after salbutamol: in five, predicted values for FVC were exceeded. 6 Patients with chronic bronchitis may benefit from the combination of theophylline and salbutamol if steady state theophylline concentrations of 15-20 mg/l are achieved.
D000368:Aged; D000420:Albuterol / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D001993:Bronchodilator Agents; D004347:Drug Interactions; D004562:Electrocardiography; D005541:Forced Expiratory Volume; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007700:Kinetics; D008875:Middle Aged; D013806:Theophylline / Q000097:blood / Q000494:pharmacology*
D001993:Bronchodilator Agents; D013806:Theophylline; D000420:Albuterol