Equivalence of as-required salbutamol propelled by propellants 11 and 12 or HFA 134a in mild to moderate asthmatics

This randomized, double-blind, parallel-group study compared the efficacy a nd tolerability of as-required salbutamol 100 mu g administered from either a chlorofluorocarbon (CFC) pressurized metered dose inhaler (pMDI; Ventoli n(TM)) or from a non-CFC hydrofluoroalkane (HFA) 134a pMDI (Ventolin(TM)CFC -free) in patients with mild to moderate asthma. All patients (n = 423) con tinued with their standard asthma therapy, and recorded their daily use of study medication, morning and evening peak expiratory flow (PEF) and sympto m scores, throughout the 4-week treatment period. Clinic lung function was measured at 2-week intervals. The median daily use of inhaled study medication remained constant at four actuations per day throughout the study in both treatment groups and statis tical analysis indicated that the two formulations were equivalent. Small i mprovements in both treatment groups were reported in mean morning and even ing PEF, clinic forced expiratory volume in 1 sec and clinic PEF and there were no significant differences between the two groups. Both formulations w ere well tolerated. This study indicates that as-required salbutamol 100 mu g administered via a HFA 134a pMDI is as effective and safe as the currently available CFC-pro pelled formulation.