ABSTRACT
Twenty-one patients with chronic bronchitis entered a double-blind, cross-over study in which they received sustained-release theophylline ('Nuelin'SA) 350 mg daily for 4 days followed by 700 mg daily for 4 days and matching placebo tablets for 8 days with one week separation. Seventeen patients completed the study. Three patients receiving higher doses for weight than the mean for the group were withdrawn because of side-effects. Mild side-effects only were reported in six other patients. Theophylline given twice daily produced a steady-state mean serum concentration of 13.9 micrograms/ml, 13 patients having concentrations inthe range of 10-20 micrograms/ml. There was no demonstrable improvement of symptoms but pulmonary function measurements in the clinic at the end of active treatment showed a statistically significant improvement in PEFR, 1-second forced expiratory volume and forced vital capacity.
