Efficacy and safety of doxofylline compared to theophylline in chronic reversible asthma -- a double-blind randomized placebo-controlled multicentre clinical trial.

Author(s): Goldstein MF, Chervinsky P

Affiliation(s): The Asthma Center, Philadelphia, PA 19107-1578, USA. Gpike35@aol.com

Publication date & source: 2002-04, Med Sci Monit., 8(4):CR297-304.

Publication type: Clinical Trial; Multicenter Study; Randomized Controlled Trial

BACKGROUND: Experimental studies have shown that doxofylline is endowed with a remarkable bronchodilator activity with less extra-respiratory effects than theophylline. This trial was designed to compare the efficacy and safety of doxofylline, theophylline, and placebo in patients with chronic reversible bronchial asthma. MATERIAL/METHODS: Three hundred forty-six patients were randomly assigned to a 12-week oral treatment with either doxofylline 400 mg t.i.d. (high dose), doxofylline 200 mg t.i.d. (low dose), theophylline 250 mg t.i.d. (active control) or placebo. Pulmonary function tests (PFTs) were performed biweekly. Patients kept records of peak flow meter (PFM) measurements, asthma attack rate and beta-2-agonist use (albuterol). RESULTS: Changes in FEV1 2 hours after the administration of treatments versus baseline exhibited statistically significant differences between doxofylline 400 mg t.i.d. and placebo and between theophylline and placebo. Similar differences were monitored on the other variables (FVC, PFER, FEF(25-75%). Asthma attack rate and use of albuterol decreased remarkably with doxofylline 400 mg t.i.d. and theophylline. There were few statistically significant differences between doxofylline 200 mg t.i.d. and placebo. Significantly more patients had to interrupt treatment because of adverse events under theophylline than under doxofylline 400 mg t.i.d. (p=0.001). With doxofylline 400 mg t.i.d., the number of patients treated to spare one drop-out due to theophylline was 5. CONCLUSIONS: This study provides evidence that doxofylline 400 mg t.i.d. is an effective treatment for relieving airway obstruction and displays a better safety profile with respect to theophylline 250 mg t.i.d. with a favorable risk-to-benefit ratio.