Positive benefits of theophylline in a randomized, double-blind, parallel-group, placebo-controlled study of low-dose, slow-release theophylline in the treatment of COPD for 1 year

Objective and background: Increasing evidence suggests that low-dose theophylline has anti-inflammatory benefits and is safe in the treatment of COPD. This study aims to evaluate the efficacy and safety of low-dose, slow-release oral theophylline administered over a 1-year period in patients with COPD. Methods: A randomized, double-blind, parallel-group, placebo-controlled trial was carried out. In total, 110 participants with COPD were randomly assigned to receive slow-release theophylline (100 mg b.i.d.) or placebo for 1 year. Use of medicine and symptoms recorded by diary cards; pulmonary function, exacerbations of COPD, quality of life and the use of rescue medicine were evaluated. Superiority test was used to estimate the efficacy. Results: Of 110 participants, 85 (77.3%) complied with the protocol, with 42 subjects in theophylline and 43 subjects on placebo. In both intention-to-treat and per-protocol population analysis, greater improvement in pre-bronchodilator FEV1 (P= 0.038 and P=0.070, respectively), lower frequency of COPD exacerbations (P= 0.047 and P= 0.035, respectively), fewer days of COPD exacerbations (P= 0.045 and P=0.046, respectively), lower frequency of clinical visits (P= 0.017 and P = 0.039, respectively), greater improvement in satisfaction with treatment (P= 0.014 and P = 0.004, respectively) were found in the theophylline group than in the placebo group. In per-protocol population, greater improvements in quality of life (P= 0.047) were also observed in the theophylline group and the mean time to the first exacerbation was delayed in theophylline group in comparison with placebo group (P= 0.047). Drug-related adverse events such as stomach discomfort (3.51%), headache (3.51%), insomnia (1.75%) and palpitation (1.75%) were found in the theophylline group. Conclusions: Low-dose, slow-release oral theophylline is effective and well-tolerated in the long term treatment of stable COPD, although it does not improve post-bronchodilator lung function.