Gastric acid–suppressing medications such as proton pump inhibitors are associated with a significant increase in subsequent antiallergy medication use, particularly in older individuals.
In a population-based study of health insurance data from 8.2 million people, Austrian researchers looked for prescriptions of gastric acid inhibitors, antiallergy drugs, or other commonly prescribed (lipid-modifying and antihypertensive) drugs as controls from 2009-2013.
According to results published in Nature Communications, gastric acid–suppressing drugs were associated with an overall 96% higher rate of subsequent prescriptions for antiallergy medications than among the general population not taking gastric acid–suppressing drugs (P less than .001). Among individuals aged 60 years or older, the rate of allergy medication prescriptions after acid-suppressing treatment was more than five times higher than that in the general population.
The rate of antiallergy medication use after acid-suppressing medication prescription was threefold higher than the rate seen after lipid-modifying or antihypertensive drug prescription.
“Our findings confirm an epidemiological association between gastric acid suppression and development of allergic symptoms, in line with previous mechanistic animal trials and human observational studies,” wrote Galateja Jordakieva, PhD, of the department of physical medicine, rehabilitation, and occupational medicine at the Medical University of Vienna, and coauthors.
All groups of acid-inhibiting medications were associated with a higher rate of subsequent antiallergy medication prescriptions. The only exception was prostaglandin E2 medications, but the authors said that here the numbers were too low to draw conclusions.
The hazard rate for antiallergy medications also increased with increasing numbers of daily doses of acid-suppressing medication, the study showed. The hazard rate for the lowest quartile – up to 20 daily doses per year – was a significant 28% higher than that of the general population, while the third quartile (68-213 daily dose per year) was associated with a 2.67-fold higher hazard. A similar increase was seen for the fourth quartile of acid suppression–medication dosing.
The authors established that just six daily doses of acid-suppressing drugs in a year were associated with significantly earlier prescriptions of antiallergy medication.
Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine, emphasized in an associated commentary that the findings reflect association, not causation. “There are many possible explanations for the observed association ... In fact, the data make other explanations more than likely to be the cause of allergies.”
Coprescriptions of aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) are common among PPI users and “are among the drugs that are very well known to increase the risk of an allergic reaction.” The data show that antiallergy medicines are prescribed at a relatively similar rate at all ages, while PPI prescribing increases in the elderly.
“If the rate of prescription of PPIs shows a steep rise with age and they are a significant cause of allergies, then the anti-allergy medicines ... should also show a steep rise with age. The fact that they don’t, either means they show no relation or that any relation has a minimal effect on allergies,” Dr. Evans said. “Nearly all drugs can have very rare allergic reactions, including PPIs, but this paper does not help to show what the true rate is of these very rare reactions, or whether they are caused by PPIs alone. The design and analysis methods in the paper are likely to exaggerate their apparent occurrence.”
The study was supported by Burgenländische Gebietskrankenkasse and the Austrian Science Fund. No conflicts of interest were declared.
SOURCE: Jordakieva G et al. Nat Commun. 2019 Jul 30. doi: 10.1038/s41467-019-10914-6.