Objective: Recent studies have found that theophylline exerts anti-inflammatory and immunomodulatory effects. This study was performed to compare the efficacy of inhaled corticosteroids (ICS) combined with slow-release theophylline (SRT) with that of double-dose ICS in asthma control, anti-inflammatory activity and safety.
Methodology: In a randomized, open, parallel, control trial, 41 patients with asthma were randomly treated with either beclomethasone dipropionate 500 microg b.i.d. (BDP group) or a combination of BDP 250 microg b.i.d and SRT 0.2 g b.i.d. (SRT/BDP group) for 6 weeks. At the start and at the end of treatment, lung function testing and sputum induction were performed, and plasma cortisol levels were measured. Sputum was analyzed for cell differential counts and the interleukin (IL)-5 level. Patients kept a record of peak expiratory flow (PEF), symptom score, and beta2-agonist use.
Results: Significant increases in the morning and the evening PEF and FEV1 were observed (P < 0.05), together with an obvious reduction in symptom score and beta2-agonist use (P < 0.01). Significant decreases in the percentage eosinophils and IL-5 level in induced sputum also occurred (P < 0.05). However, there was no difference between the two groups for all these parameters. There was no significant change in the plasma cortisol level for either group.
Conclusions: Both ICS combined with SRT and double-dose ICS had the same effect on asthma control, improving symptoms and ameliorating lung function. Both therapies had similar anti-airway inflammatory effects and therapeutic safety. Combining SRT with ICS may allow a reduction in ICS dose when treating asthma.