(Reuters Health) - A 2008 ban on chlorofluorocarbons (CFCs) has ended up being particularly costly for people with asthma.

The ban changed the type of albuterol inhaler available in the U.S., and since then costs have gone up and inhaler use has gone down, according to a new study.

Albuterol inhalers prevent and treat wheezing, shortness of breath, coughing, and chest tightness due to asthma or chronic obstructive pulmonary disease.

Generic albuterol inhalers using CFCs were banned and were replaced by more expensive inhalers using hydrofluoroalkane (HFA).

Chlorofluorocarbons deplete the ozone layer and have been gradually phased out of use since 1987, but until 2005 the Food and Drug Administration had said CFC inhalers are essential medicines, so they were exempt.

The FDA reversed that decision in 2005 and CFC albuterol inhalers were no longer manufactured, the authors explain in JAMA Internal Medicine.

The active medication in the replacement HFA inhalers is exactly the same. Only the propellant has been changed, according to Dr. Rita F. Redberg of the University of California, San Francisco, who wrote a commentary accompanying the new study.

The inhaler switch “had minimal or no environmental benefits, but great benefits to pharmaceutical companies,” Redberg told Reuters Health by phone.

Since the HFA inhalers are newer and still under patent, these branded inhalers are more expensive than the CFC generics had been.

The researchers studied private insurance claims data for albuterol inhalers among more than 100,000 adults and 37,000 children with asthma from 2004 to 2010 and asthma-related hospitalization records.

Average out-of-pocket cost rose from $13.60 per inhaler prescription in 2004 to $25 in 2008, which declined to $21 by 2010. The number of patients using their inhalers declined “modestly,” said lead author Dr. Anupam B. Jena of Harvard Medical School in Boston, and asthma-related hospitalizations, emergency department visits, and outpatient visits did not change over time.

“The uninsured population, who were not in this study, would face the full increase,” Jena said in a phone interview with Reuters Health. “Even a $10 dollar increase, about a doubling, is quite large in terms of copayment increases.”

Costs went up but use only declined modestly, which may be because these inhalers are really important medications, so when prices go up people are reluctant to reduce their use, Jena said.

“Here’s an example of a really well intended public policy geared toward improving the environment, but the question is in this particular case whether or not the reduction in use of these propellants was worth it,” he said.

About 20 million people in the U.S. have asthma, and their use of these inhalers probably does not have a significant effect on the ozone layer, he said.

Price regulation or public subsidies could have limited cost increases, he said.

The Affordable Care Act of 2010 expanded insurance coverage, so would have softened the economic impact of the ban somewhat, but otherwise does not address high costs of branded medications, he said.

“HFA inhalers should be going off patent soon, in five years there may be generic HFA inhalers on the market,” and costs will decrease again, Jena said.

SOURCE: bit.ly/1K1UgOP JAMA Internal Medicine, online May 11, 2015.