Comparative efficacy of oral sustained released bronchodilator in stable asthmatics

Double blind randomized trial of oral conventional and sustained release bronchodilators was undertaken to observe comparative efficacy in 30 patients older than 15 years. All cases selected were stable asthmatics at least for last 2 years having FEV1 improvement > or = 20%. Basal Pulmonary functions like FEV1, FVC and PEFR were recorded before and after drug administration at 1/2, 1, 2, 3, 4, 6, 8, 10, 12 and 24 hours. Four drug regimens were given as a single dose in the morning on randomized crossover manner on 1st, 4th, 7th and 10th days, sustained release theophylline 300 mg+salbutamol 4 mg (Drug I), salbutamol 4 mg + theophylline 300 mg (Drug II), salbutamol sustained released (asthalin SA) 8 mg (Drug III), salbutamol sustained released (ventorlin CR) 8 mg (Drug IV). Mean FEV1 changes observed at 0, 6 and 12 hours for all the drugs were compared which showed no statistical significance (t = 2.3876). Therefore, we conclude that using single dose fixed combination of oral salbutamol and aminophylline either in a plain or slow released form have no additive bronchodilator effect as compared to salbutamol alone in stable asthmatics.