Efficacy of a 12-hour sustained-release preparation in maintaining therapeutic serum theophylline levels in asthmatic children.

The purpose of this study was to determine whether a new sustained-release theophylline preparation TheoDur could maintain therapeutic serum theophylline levels in asthmatic children on a 12-hour dosage regimen. Twenty asthmatic children aged 6 to 18 years with a mean of 11.4 years who required continuous theophylline therapy for control of their asthma were enrolled in the study. Each patient's dosage was titrated to achieve a six-hour postdose serum theophylline level between 10 and 20 microgram/ml. The patients required a mean +/- SEM dose of 10.0 +/- 0.54 mg/kg every 12 hours which gave a mean +/- SEM six-hour postdose serum theophylline level of 15.65 +/- 0.72 microgram/ml. At the end of five days on this dosage, the patients were admitted and serum theophylline levels were determined every three hours for 24 hours. The mean +/- SEM difference between maximum and minimum serum theophylline levels (delta TL) for the group was 4.5 +/- 0.3 microgram/ml. There was not a significant difference in the delta TL between the two age groups (6 to 9 years, 4.5 +/- 0.5 microgram/ml and 10 to 18 years 4.5 +/- 0.4 microgram/ml). In conclusion, TheoDur will maintain therapeutic serum theophylline levels with minimal fluctuations in asthmatic children on a 12-hour dosing schedule.