The value of maintenance theophylline in steroid-dependent asthma.

We examined the value of maintenance theophylline at serum concentrations of 10 to 20 micrograms per milliliter in a placebo-controlled, randomized, double-blind trial of 33 children with steroid-dependent chronic asthma. Patients were free of all symptoms 63 +/- 6 per cent of the days (mean +/- S.E.M.) when taking theophylline as compared with 42 +/- 6 per cent when taking placebo (P < 0.01). Inhaled metaproterenol was required twice as often with placebo (P < 0.01), and additional daily corticosteroids were needed more than three times as often with placebo (P = 0.02). Daily peak flow measurements improved with theophylline (P < 0.01) as did monthly spirometric measurements and residual volume measured by plethysmography. Theophylline was associated with a 50 per cent increase in the number of patients able to complete an exercise test (P = 0.01) and with a smaller decrease in forced expiratory volume in one second among patients completing the exercise (P < 0.02). We conclude that maintenance bronchodilator therapy with theophylline can provide clinically important benefit for patients with chronic steroid-dependent asthma.