[Long-term therapy with a retard theophylline preparation].

The present study was conducted to investigate the therapeutic effect of long-term treatment with a slow-release theophylline preparation on the pulmonary functions FEV1 and peak exspiratory flow (PEF). A total of 908 patients took part in this open multicenter study. Treatment with the slow-release theophylline resulted in an increase of FEV1 and PEF of about 20% in asthma and between 11% and 14% in COPD. Apart from theophylline itself, the galenic nature of the slow-release formulation also contributed to the therapeutic effect.