A drug used to treat acid reflux has often been used for hard-to-treat asthma. A new study finds that it does not help children with the breathing disease and may cause side effects.
The latest study showed that use of these heavily promoted acid-blocking drugs, called proton pump inhibitors in the US children in recent years. University of Arizona asthma expert Dr. Fernando Martinez says the study results suggest doctors should stop that practice. Dr. Martinez wrote an accompanying editorial.
PPIs “are often prescribed for poorly controlled asthma regardless of reflux symptoms, and there have been large increases in the use of PPIs among children between 2000 and 2005.... Hence, it is of clinical importance to determine whether anti-reflux therapy, the most common of which are PPIs, improves control of asthma in children,” write Janet T. Holbrook, from the Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, and colleagues from the Writing Committee for the American Lung Association Asthma Clinical Research Centers in this week's Journal of the American Medical Association.
The pathology of acid reflux involves stomach acid backing up into the throat, causing irritation and often symptoms including heartburn. Asthma is an unrelated lung disease involving narrowed airways, with symptoms including wheezing, breathing difficulties and coughs. Sometimes acid reflux can cause similar respiratory symptoms and in children it often occurs without heartburn.
Some doctors believe that airway irritation caused by acid reflux may make asthma worse, and that undiagnosed acid reflux might be a reason why some people on standard asthma medicines continue to have symptoms. Prescribing acid-blocking drugs is thus common in people with poorly controlled asthma even if they have no obvious symptoms of reflux.
Earlier studies in adults have shown similar inefficacy of another acid-blocking drug, Nexium. Still, those drugs continue to be widely used in patients with asthma but no reflux symptoms, said Dr. Holbrook.
Holbrook said results from both studies likely apply to all proton pump inhibitor drugs, including those sold over the counter. Prevacid or Lansoprazole became available without a prescription during the study. The new study involved about 300 children and adolescents at 19 centers whose asthma wasn't adequately controlled by steroid drugs. Half were given daily Prevacid pills for six months; the others received dummy pills.
Results showed that asthma symptoms didn't improve in either group. They also didn't improve in a subgroup of study kids who had airway tests that revealed undiagnosed reflux disease, Holbrook said. Further bronchitis was twice as common in kids on Prevacid, and they were also 30 percent more likely than the others to develop colds and sore throats. But it's possible that these drugs interfere with helpful bacteria in the body that fight infection, said Dr. Chitra Dinakar, an asthma specialist at Children's Mercy Hospitals and Clinics in Kansas City, Mo. who took part in the study.
In an accompanying editorial, Dr. Martinez, notes that although it is not a statistically significant difference, the increase in activity-related bone fractures in the lansoprazole group also raises concerns. This potential complication has prompted an advisory from the US Food and Drug Administration about the risk for fractures in adults receiving chronic PPI therapy. “In this context, a less conservative test assessing if the odds ratio was significantly greater than 1.0 (not just different from 1 in any direction) might have been more appropriate and may have yielded a statistically significant result,” writes Dr. Martinez. Overall, however, Dr. Martinez praises the work of Dr. Holbrook and colleagues and concludes that “[g]iven their potential adverse effects, these medications should thus be used with great restraint for treatment of GER/[gastroesophageal reflux disease] during childhood. The substantial increase in use of PPIs in children during the last decade is worrisome and unwarranted.”
Dr. Daniel Searing, an allergy and asthma specialist at National Jewish Health in Denver, said the study provides important information to pediatricians wondering if the previous study in adults was applicable to children.
The National Institutes of Health and American Lung Association financially supported the study.
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