Addition of Theophylline or Increasing the Dose of Inhaled Corticosteroid in Symptomatic Asthma: A Meta-Analysis of Randomized Controlled Trials

Purpose: Low-dose theophylline has anti-inflammatory effects. The aim of this study was to evaluate the effects of adding theophylline compared with increasing the dose of inhaled corticosteroid (ICS) on symptomatic asthma. Materials and Methods: The associated literature was acquired through deliberate searching and selected based on the established inclusion criteria for publications. The extracted data were further analyzed by a meta-analysis. Results: Four randomized, controlled, parallel studies were selected. Addition of theophylline produced a greater increase of forced expiratory volume in one second as %predicted (FEV(1)pred) by 2.49% [95% confidence interval (CI) 1.99-3.00; z = 9.70; p < 0.001], compared with increasing the dose of ICS. There was no difference between the two treatments in terms of peak expiratory. flow (PEF). Conclusion: Addition of theophylline to ICS has similar therapeutic effects on improving lung function as increasing the dose of ICS in the treatment of symptomatic asthma.