Theophylline has been used as a
bronchodilator in acute and chronic
asthma management but recent evidences suggest that it has anti-inflammatory effects. Therefore, we investigated the
therapeutic effect of slow-release
theophylline in mild to moderate asthmatic patients. Symptomatic 19 patients with mild
asthma who were treated with inhaled beta 2-agonist alone, and 17 subjects with moderate
asthma who were treated with moderate dose of inhaled
corticosteroid (
beclomethasone dipropionate, BDP, 400-800 micrograms/day) were enrolled to the present study. After two-week run-in period, slow-release
theophylline was administered for six to eight weeks and
asthma symptoms, respiratory function, airway
inflammation evaluated by the inhalation of hypertonic saline, and airway reactivity to
histamine were investigated during observation period and
after treatment.
Asthma symptom score was significantly improved after
theophylline treatment in both groups. Morning peak expiratory flow was significantly elevated but FEV1 was not significantly improved by the additional treatment with slow-release
theophylline in both groups. Significant decreases in the percentages of total and EG2 + eosinophils in induced sputum demonstrated that slow-release
theophylline has anti-inflammatory effect in patients with
asthma despite the treatment with inhaled
corticosteroid. Because recent reports suggest that
theophylline may act as an anti-inflammatory
drug even in low dose concentration, we also investigated the effect of plasma
theophylline concentration on the airway
inflammation. Patients were divided into two groups by the plasma concentration of
theophylline, more than 10 micrograms/mL which is necessary to dilate airway and below 10 micrograms/mL, referred to as low dose concentration of
theophylline. The results suggest that the administration of slow-release
theophylline significantly decreased the percentages of both total and EG2 + eosinophils in induced sputum in both concentration groups. However, airway reactivity to
histamine did not significantly change by the treatment. Taken together, we conclude that low dose treatment of slow-release
theophylline has an anti-inflammatory effect and treatment with slow-release
theophylline alone or the additional use with inhaled
corticosteroid is an effective
therapy for the management of mild to moderate
asthma.