Inhaler switch

At press time, the switch from the CFC albuterol inhalers to their HFA cousins is well under way in most parts of the country, and Schering-Plough confirmed that CFC-propellant albuterol inhalers are no longer being made. This change to HFA propellant is a result of a 2005 mandate by the Food & Drug Administration in response to concerns about the detrimental effect of CFCs on our ozone layer. These concerns led to an international treaty, the Montreal Protocol on Substances that Deplete the Ozone Layer, which addresses several groups of halogenated hydrocarbons shown to play a role in ozone depletion and provides a timetable for their phaseout. Initially, CFC propellants used in asthma inhalers were granted an exception because there were no acceptable substitutes, but the development of HFA propellants set the stage for the CFC phaseout.

While the new HFA inhalers are more environmentally friendly, they also have other differences from the CFCs. Some individuals worry that their HFA inhaler is not as effective as the CFC version. They don't feel the same "thrust" into their lungs. But while the "feel" is different, some studies conclusively show the therapeutic effect is not. In an article in the March 29 New England Journal of Medicine, Leslie Hendeles, Pharm.D., professor of pharmacy and pediatrics, University of Florida, and his colleagues meticulously analyzed the data comparing CFC MDIs and HFA MDIs. He stated, "The actual scientific objective evidence we reviewed in our article shows unequivocally that [the CFC MDI albuterol and the HFA MDI albuterol] are equivalent in therapeutic effect in terms of relieving airway obstruction."

But, pharmaceutically, the constituents of the HFA propellants vary, and they cannot be considered equivalent to one another. Hendeles noted that some contain ethyl alcohol while others do not. Kristen Binaso, R.Ph., CCP, FASCP, director of strategic alliances and business development, American Pharmacists Association, commented, "The HFA products are all BX-rated—that is, they're not substitutable for one another." For this reason, by law, switching an individual from a CFC inhaler to an HFA inhaler requires that a pharmacist obtain a new prescription from the prescriber—and some of the clinical pharmacists interviewed for this story expressed concern because they do not see this happening.