Effects of Oral Doxofylline and Procaterol on Chronic Obstructive Pulmonary Disease: A Randomized Crossover Study

<b>Background</b>: Oral bronchodilators may serve as an adjunctive therapy in patients with chronic obstructive pulmonary disease (COPD). This study aimed to evaluate the effects of oral doxofylline and oral procaterol on lung function and clinical symptoms in COPD patients. <b>Methods</b>: A crossover randomized controlled trial was conducted in patients with clinically stable COPD. Participants first received either doxofylline or procaterol for 4 weeks, followed by a 1-week washout period. Assessments included the modified Medical Research Council (mMRC) dyspnea scale, COPD assessment test (CAT) scores, and 6-minute walking distance (6MWD). Pulmonary function was evaluated using spirometry with bronchodilator (BD) testing and all adverse events were recorded. <b>Results</b>: Twenty patients were randomly assigned to begin treatment with either doxofylline or procaterol. Their mean age was 71.7 ± 9.4 years. After four weeks of treatment, the doxofylline group showed significantly greater improvement in pulmonary function parameters (post-BD peak expiratory flow and post-BD forced expiratory flow 25-75) compared to the procaterol group. However, there were no significant differences in mMRC scores, CAT scores, or 6MWD between the two groups. More neurological adverse events were observed in the doxofylline group compared to the procaterol group (35% vs. 5%, <i>p</i> = 0.044). <b>Conclusions</b>: Doxofylline improved pulmonary function in COPD patients but did not provide superior functional performance compared to procaterol. Neurological adverse events were more frequently associated with doxofylline. Doxofylline may serve as an adjunctive therapy to enhance pulmonary function in COPD patients, but caution is advised due to its potential side effects.