LONDON – Earlier this month a study out of New Zealand showed that the use of acetaminophen in infants is linked to almost double the risk of asthma and allergies by age 6 or 7. Now there is more news on acetaminophen and asthma, but this time for adults.

A study out of Europe shows that adults are at risk if they take acetaminophen on a regular basis. The study looked at 521 people with asthma as compared to 507 control subjects with no diagnosis and no asthma-related symptoms, from 12 centres across the European continent. Results from the study show that those who take a weekly dose of the common painkiller are almost 3 times more likely to have asthma compared to adults who don’t take this medication. The research found no similar relationship between asthma and any other analgesic; however, critics of the study indicate that it did not control well for use of other pain or fever medication.

While another important step in the study of acetaminophen, this research does not yet prove that acetaminophen causes asthma symptoms.

So, why the sudden interest in acetaminophen and asthma? Statistics showed that countries with high rates of acetaminophen use also had significantly higher rates of asthma. This prompted a number of additional studies of this commonly used over-the-counter drug, looking at specific populations (such as infants), with astonishing results.

Why would acetaminophen increase asthma risk? Researchers hypothesize that the medication somehow lowers the levels of a key antioxidant, glutathion. Glutathion helps to protect airways.

Adults should not automatically switch from acetaminophen to other analgesics, however. There are indications in the literature that other non-steroidal anti-inflammatory drugs (such as aspirin or ibuprofen) may precipitate an asthmatic attack in those sensitive to this class of drugs.

Consumers should be aware that acetaminophen is commonly sold under the brand name Tylenol in North America.

Source: European Respiratory Journal