Asthma Inhalers Change Design
For the millions of asthma patients who use inhalers daily, the phaseout of ozone-depleting propellants is forcing a switch to new devices. That may not seem like a huge problem, but many people aren't using the new devices correctly potentially jeopardizing their health.As with all inhalers, patients must learn the proper breathing technique so that the medication reaches diseased lung tissues. Those who don't risk having a fatal asthma attack.And many people have poor technique. Studies have shown that 40% of all patients don't use the current inhalers properly.
Compound that improper technique with unfamiliar devices, and the situation becomes more serious.Two types of asthma medications are currently taken with an inhaler long-acting steroids, which reduce chronic airway irritation and inflammation, and bronchodilators, which provide immediate relief from breathing difficulties.Both medications have traditionally come in metered-dose inhalers that use chlorofluorocarbon gases to launch a spray of the medication into the mouth at close to 90 mph.
Because many patients don't like medication shot into their mouths, or have trouble coordinating their breath with extremely rapid release of the medication, they prefer using an intermediate device called a holding chamber, or spacer. They fill the chamber with their medication, then inhale it slowly and deeply, which gives them more control.Because of the gradual worldwide phaseout of chlorofluorocarbons, which have been linked to depletion of the ozone layer, some drug manufacturers have begun to substitute an ozone-friendly propellant called hydrofluoroalkane, or HFA.
Devices using HFA are easier for many people to use because they launch the medication more slowly, at 30 mph.But other makers have begun to replace the aerosol inhalers used to dispense steroids with breath-activated, dry powder devices. With some of these, users push a lever to pop open a preloaded dose of powder; others must be manually loaded. In both, patients must take a quick, forceful breath that draws the medication into the lungs."It's the exact opposite of using a slow, deep breath. That's what confuses people," says Dr. Joe Spahn, a pediatric allergist and immunologist at National Jewish Medical and Research Center in Denver. "If it's not done correctly, it's like you're not taking it at all."
Those asthmatics at greatest risk from the transition to new inhalers are the very old and the very young.Children age 4 or younger "don't have the coordination or the developmental skill" to inhale powerfully and get the full dose of steroid powder, he said. Those children, as well as senior citizens who sometimes can't coordinate their breathing, would do better if they use the inhalers powered by the alternative propellants, along with holding chambers, or nebulizers machines that allow them to breathe medicated air or mist for several minutes.With only the steroid inhalers available in the dry powder devices, "the real big problem with this whole thing is that people are going to have to know both techniques," Spahn said, because even bronchodilators with environmentally friendly propellants still rely upon the old breathing technique.By Jane E. AllenLos Angeles Times - 12/30/2003Topic: Air Pollution