SAN ANTONIO -- Gastroesophageal reflux is a potential trigger for asthma, and should be investigated in patients with persistent asthma even if they report no symptoms of reflux, Susan Harding, M.D., said at the annual meeting of the American Academy of Allergy, Asthma, and Immunology.
"Silent reflux is common in asthmatics," said Dr. Harding, associate professor of medicine at the University of Alabama at Birmingham.
In one study conducted by her group, 62% of consecutive adults and 23% of children with asthma but with no symptoms of gastroesophageal reflux disease (GERD), had abnormal esophageal acid results when tested (Am. J. Respir. Crit. Care Med. 2000;162:34-9).
"A lot of times people think that having reflux is normal, and so the first time you ask them they say they don't have a problem. But if you call them a week later after they've had a chance to think about it, often you will find that they have noticed problems with certain foods or with eating late at night," she told this newspaper.
Dr. Harding advised physicians to ask patients with persistent asthma about symptoms of GERD, such as reflux and heartburn. Regardless of the presence of symptoms, she suggested an empirical trial of a proton pump inhibitor (PPI), which will clarify whether reflux is causing, or contributing to, the patient's asthma.
"I recommend a high-dose PPI, twice a day for at least 3 months, because it takes time to get acid out of the picture and for the airway inflammation to cool down," she said.
Studies have shown that PPI therapy can improve symptoms and reduce medication use in reflux-triggered asthma, but the effect on pulmonary function has been less striking, she said.
The best study is a soon-to-be published multicenter, placebo-controlled trial of 207 patients with moderate to severe persistent asthma. The results show some promising effects of high-dose PPI therapy (lansoprazole 30 mg twice daily) on asthma symptoms, exacerbations, quality of life, and pulmonary function, Dr. Harding said.
Dr. Harding advised that asthma symptoms should be monitored before and during GERD therapy, and if they do not improve, 24-hour esophageal pH testing (while on GERD therapy) should be considered to confirm that acid is adequately suppressed. If acid is not suppressed, the PPI dose should be increased. But if acid is suppressed, acid reflux is likely not the trigger for the patient's asthma, and GERD should be treated from a symptomatic standpoint only, she said.
Dr. Harding advised cutting the PPI dose to once a day with improvement of asthma symptoms seen with GERD therapy.
"I would also consider adding a prokinetic agent, because reflux is more of an esophageal motility problem, not an acid problem. But metoclopramide, the only prokinetic agent available in the U.S., has a high incidence of central nervous system effects," she said.
And finally, laparoscopic fundoplication has a role in selected patients. "I usually only refer to the surgeon when I know their asthma is truly related to gastroesophageal reflux and they have asthma improvement on reflux therapy," she said.
The link between asthma and GERD is poorly understood, and there is no clear indication as to which condition precedes the other. Some experts believe aggressive treatment of asthma could relieve some symptoms of GERD--but, paradoxically, certain asthma medications have been known to cause acid reflux, Dr. Harding said.
"The asthma medications that seem to worsen reflux include theophylline at high levels, oral corticosteroids, and then repeated amounts of nebulized albuterol, which may alter esophageal function."
Dr. Harding advised treating reflux aggressively in asthma patients, and approaching asthma therapy aggressively as well, with attempts to avoid potential GERD exacerbators.
BY KATE JOHNSON
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