Combined theophylline/beta-agonists maintenance therapy in chronic asthma.

The therapeutic value of adding a slow-release theophylline product (Theo-Dur) to the regular treatment program consisting of beta-stimulants and steroids was evaluated in 31 adult asthmatics. Theophylline in a dose of 300 mg or placebo was administered twice daily during two 14-day periods in a randomized double-blind cross-over study. PEF and asthma symptoms were recorded daily. In the morning, 12 h after tablet intake, spirometry was performed and the theophylline concentration determined. The addition of theophylline slightly, but statistically significantly, increased the daily PEF values and reduced dyspnoea, but not cough, sputum volumes and aerosol consumption. The patients showed preference for the combined treatment. Spirometry at the end of each period did not differ significantly between treatments. The mean theophylline concentration in the morning 12 h after tablet intake was 39 mumol/l (range 15-81 mumol/l). The results of the study suggest that the addition of a slow-release theophylline preparation to beta-stimulant therapy provides further relief of asthma symptoms without an unacceptable increase in the incidence of side-effects.