Switching patients with asthma from chlorofluorocarbon (CFC) albuterol to hydrofluoroalkane-134a (HFA) albuterol

Chlorofluorocarbon (CFC) propellants deplete stratospheric ozone. Productio n and use of CFCs, except for certain critical exemptions, has been prohibi ted by the Montreal Protocol. Use of CFCs as propellants in metered-dose in halers (MDIs) is still allowed, but the U.S. Food and Drug Administration i s planning the transition to alternative propellants for use in MDIs. Hydro fluoroalkane-134a (HFA), a non-ozone-depleting propellant, has been used to reformulate albuterol (HFA albuterol). This study evaluates whether compar able safety and efficacy continues for 12 weeks after patients with asthma are switched from CFC albuterol to HFA albuterol. Patients with asthma stab ilized on CFC albuterol during a 12-week safety and efficacy trial were ran domized to either continue receiving CFC albuterol or to be switched to rec eive HFA albuterol in a yearlong safety and efficacy trial. Safety and effi cacy were compared over the first 12 weeks of the yearlong trial between pa tients who had remained on CFC albuterol and those who had been switched to HFA albuterol. Bronchodilator efficacy was evaluated by serial spirometry for 6 hr after the patients self-administered the study drug in the clinic. Safety was assessed by measuring changes in pulse rate, blood pressure, an d electrocardiogram (ECG) intervals after dosing with study drug, monitorin g adverse events, and performing prestudy and poststudy laboratory testing and physical examinations. No significant differences in bronchodilator eff icacy between the patients continuing to receive CFC albuterol and those sw itched to HFA albuterol were found in the 12 weeks after the switch. No dif ferences between the two products were found for changes in pu Ise rate, bl ood pressure, and ECG intervals. Adverse event profiles were similar for th e two products, except the patients remaining on CFC albuterol reported inc reased asthma symptoms and rhinitis significantly more often than the patie nts switched to HFA albuterol. No clinically meaningful changes in laborato ry tests or physical examinations were found in either treatment group. Pat ients with asthma switched from CFC albuterol to HFA albuterol receive comp arable bronchodilation with a similar safety profile as those continuing to receive CFC albuterol.