Comparison of a new sustained-release theophylline preparation, TheoBeads, with Theo-Dur tablets in children with asthma

A new, slow-release theophylline formulation for children, TheoBeads, which has the potential for once-daily dosing, has become available. We report the results of a study of pediatric patients whose medication was changed from Theo-Dur tablets b.i.d. to TheoBeads q.d. Forty-nine children with asthma (aged 6-12 years) were treated with b.i.d. Theo-Dur to produce therapeutic maximum and minimum concentration levels (i.e., 8-20 micrograms/ml). Approximately half the patients were then transferred to TheoBeads given q.d. at the same total daily dose and retitrated; seven patients needed to be changed to b.i.d. dosing due to unacceptable fluctuations. The other half of the patients continued on b.i.d. Theo-Dur. Following at least 5 days of steady-state dosing, serum theophylline levels were assayed over a 24-hour period. It was found that: 1. Children changed to q.d. TheoBeads showed no change in their overall asthma control based on clinical diary entries and peak flow measurements. 2. Lower Cmax and Cmin theophylline levels and a smaller area under the curve were noted for patients taking q.d. TheoBeads compared to those taking b.i.d. Theo-Dur. 3. Administration of TheoBeads q.d. resulted in a significantly larger overall peak-to-trough fluctuation and a higher percentage of patients with subtherapeutic theophylline levels in the second 12-hour period than did b.i.d. Theo-Dur administration. In summary, when children receiving b.i.d. Theo-Dur were transferred to q.d. TheoBeads, they did not maintain even and sustained therapeutic theophylline levels, although asthma control was not adversely affected during the short period of observation.