A comparative study of the use of choline theophyllinate and a sustained-release theophylline in adults with chronic asthma.

We studied 16 adults with chronic bronchial asthma by measuring the plasma theophylline concentrations and evaluating clinically the control of asthma following oral administration of choline theophyllinate (CT) and a sustained-release theophylline preparation (SRT). All 16 patients were studied in 3 one-weekly phases. These patients received CT 200 mg t.i.d. during the 1st week, no theophylline during the 2nd week and SRT 250 mg 12-hourly during the 3rd week. All other anti-asthmatic medications were maintained during the study. After the night dose of a theophylline preparation, the mean plasma trough concentration the next morning was significantly higher for SRT (9.4 mcg/ml +/- SEM 1.0) than for CT (3.6 mcg/ml +/- SEM 0.6). The mean plasma peak concentration after the morning dose was also significantly higher for SRT (11.5 mcg/ml +/- SEM 1.0) than for CT (7.4 mcg/ml +/- SEM 1.0), The mean forced expiratory volume in one second (FEV1) obtained during SRT treatment was significantly higher than during CT treatment. There was no significant difference between FEV1 measured at trough concentrations during CT treatment and during the period without theophylline. The patients had fewer symptoms of asthma and fewer side-effects from theophylline during the week they received SRT compared with the week they received CT. In this study, using the conventional dosage schedule as practised in Singapore, SRT has distinct advantages over CT in the treatment of chronic asthma.