Acid reflux link to asthma now in doubt

Asthma patients who take heartburn drugs don’t have fewer serious asthma attacks than those not getting the drugs, researchers report in the April 9 New England Journal of Medicine. The findings cast doubt on a long-held assumption that even unnoticed heartburn exacerbates asthma.

Many doctors prescribe proton pump inhibitors such as Nexium or Prilosec — used for heartburn, or acid reflux — for asthma patients. Earlier studies have suggested that acid reflux worsens asthma by irritating nerves that serve the windpipe and esophagus or by sending stomach acid up the esophagus and down into the windpipe and lungs, says study coauthor Robert Wise, a pulmonologist at Johns Hopkins University in Baltimore.

Doctors have reasoned that treating even silent acid reflux that causes no outward symptoms would thus ease the bronchial constriction and coughing of asthma attacks. Many doctors even recommend that their asthma patients get tested for hidden acid reflux disease.

In the new study, the researchers recruited people with asthma that was poorly controlled by standard drugs but excluded people who reported regular discomfort from acid reflux. Of 402 patients, half were randomly assigned to get a PPI, and the others took a placebo. Tests for acid in the esophagus showed that about 40 percent of the participants in each group had silent acid reflux.

Nevertheless, over a period of nearly six months, the rate of severe asthma attacks was no different between the people getting PPIs or placebos. These attacks included episodes of difficult breathing for two days straight, emergency visits to a doctor or the need for prednisone, a heavy-duty steroid medicine.

“This was quite unexpected,” says study collaborator Nicola Hanania, a pulmonologist at Baylor College of Medicine in Houston.

Wise estimates that 15 to 65 percent of people with asthma currently get PPIs on the assumption it will help their asthma. Those who also have heartburn should continue taking PPIs, he says. But people without obvious reflux symptoms won’t find their asthma improved by the drugs, he says.