Ibuprofen and acetaminophen, the two most commonly used pain relievers for infants and children, have had some parents worried after recent research had suggested that the medications may increase the risk of a child developing asthma. A new study, presented at a meeting of the American Thoracic Society, says the association is a misreading of the data. More from The New York Times:
The study, presented on Monday at a meeting of the American Thoracic Society in Philadelphia, found that children suffering from respiratory infections — which often lead to asthma — are simply more likely to be given over-the-counter pain relievers. These underlying respiratory infections and the fevers they cause, not the use of pain relievers, are responsible for the increased asthma risk, the authors argue.
"That's essentially what we think is happening here," said Dr. Augusto Litonjua, an assistant professor at Harvard Medical School and Brigham and Women's Hospital. "We showed that children who took acetaminophen and ibuprofen in the first year of life had higher risks of developing asthma later on. But when we accounted for their concomitant respiratory infections, the effects were no longer significant."
For the study, Dr. Litonjua and his colleagues examined data on nearly 1,200 women and their young children. The women were recruited early in pregnancy and were subsequently followed after giving birth. The researchers looked at how frequently the women used drugs like acetaminophen and ibuprofen, either for themselves or for their children. They investigated any diagnosis of asthma or wheezing symptoms, and they looked at respiratory infections, like pneumonia and bronchitis, that the children developed as infants and toddlers.
When they separated the children into groups, based on their exposure to analgesics in their first year of life, the researchers found that those with the highest exposure had a greater likelihood of developing asthma by age 7, a result consistent with earlier reports. But once they adjusted their findings to take into account the occurrence of very early respiratory infections, they found that the association between pain relievers and asthma diminished.
Much of the research linking pain relievers to asthma comes from observational studies, which are limited by a problem known as confounding by indication, in which the symptoms of an underlying disorder can be mistakenly considered a side effect of treatment.
Image: Infant receiving medicine, via Shutterstock