Efficacy and safety of levosalbutamol in patients with mild to moderate asthma compared with racemic salbutamol: results of a crossover placebo-controlled study

Aim. Effectiveness and safety of levosalbutamol metered dose inhaler (MDI) in comparison with placebo and salbutamol. Materials and methods. In this multicenter, randomized, placebo-controlled, 3-period crossover study, all asthma patients (n=91) received levosalbutamol (90 mcg), salbutamol (180 mcg), and placebo using standard MDI. Pulmonary function testing – forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) – was performed 45 and 15 minutes before and 5, 10, 15, 30, 60, 90, 120, 180, 240, 300 and 360 minutes after dosing. The primary efficacy endpoint was the baseline-corrected area under FEV1 curve from 0 to 6 hours (AUC(0–6h)). Secondary endpoints were the baseline adjusted FEV1 and FVC peak values, as well as the onset of drug action. Results. The FEV1 AUC0–6 hours analysis confirmed similar bronchodilatory levosalbutamol and salbutamol effect (p=0.595), significantly improved compared with placebo (p0.001). The peak values of FEV1 and FVC after levosalbutamol or salbutamol dosing were similar (p=0.643) and significantly higher compared with placebo group (p0.001). The active therapy effect was observed 5 minutes after dosing and throughout the entire observation period up to 6 hours, however, there was some tendency towards a longer duration of action of levosalbutamol compared to salbutamol. Levosalbutamol was well tolerated by patients; after levosalbutamol dosing twiсе fewer adverse reactions were observed compared to salbutamol. Conclusion. Levosalbutamol at a 90-mcg dose showed efficacy similar to that of salbutamol at a dose of 180 mcg, assosiated with a good safety profile.