Evaluation of a once-a-day theophylline preparation in asthmatic children.

We conducted a study to evaluate the serum theophylline concentrations and dose interval of Theolan preparation in asthmatic children. A series of serum theophylline levels were measured both in 10 asthmatic children taking Theolan once a day and 9 children twice a day. In the once-a-day group, the peak serum theophylline level was greater than 20 micrograms/ml; whereas, in the twice-a-day group, it was mostly between 10 and 20 micrograms/ml. The difference of the peak-to-trough was more fluctuant in the once-a-day group than in the twice-a-day group. These results suggest that Theolan given once a day in the evening can be useful in the management of nocturnal asthma; however, it was difficult for once-a-day administration of Theolan to sustain rigid therapeutic serum theophylline levels. Because of rapid metabolism in children, they may require a more frequent interval than once-a-day dosing to suppress the symptoms of chronic asthma.