Efficacy and Tolerability of Tratinterol Hydrochloride Tablets in Bronchial Asthma: A Multicenter, Randomized, Double-blind, Dose-finding Clinical Trial

PurposeThe aims of this study were to determine the efficacy and tolerability of different dosages of, and to identify the best dosage of, tratinterol hydrochloride tablets in the treatment of bronchial asthma.MethodsThis multicenter, randomized, double-blind, dose-finding clinical research study was completed at 3 centers in the People's Republic of China from March 2008 to February 2009. Each center selected patients with bronchial asthma whose forced expiratory volume in 1 second (FEV1) values were <80% of predicted normal (pretreatment). Patients were assigned to 1 of 3 groups, based on daily dosage: low, 50 μg/d; intermediate, 100 μg/d; and high, 150 μg/d. Doses were administered orally twice daily for 10 days. The primary end points were the changes from baseline (0 minutes) in peak expiratory flow (PEF) and FEV1 at 30 minutes and 1, 2, 4, 6, and 12 hours after administration. Secondary end points were changes from baseline in forced vital capacity and asthma scores. Tolerability was monitored throughout the study period using physical examinations, laboratory testing, and spontaneous reporting.FindingsA total of 72 patients were selected in this study (24 per group; 40 men; 32 women; mean age, 43.48 years). The efficacy analysis (per-protocol set) included 20, 20, and 22 patients in the low-, intermediate-, and high-dosage groups, respectively. In terms of the primary and secondary end points, the intermediate dosage was most efficacious, followed by the high and low dosages, respectively. All 3 dosages were well-tolerated.ImplicationsIn these patients with bronchial asthma, 100 μg/d was the dosage of tratinterol hydrochloride tablets most efficacious in terms of improvement in lung function. All 3 dosages were well-tolerated.