Acetaminophen Use in Adolescents May Double Risk for Asthma

From MedscapeCME Clinical Briefs

News Author: Laurie Barclay, MD
CME Author: Penny Murata, MD
CME/CE Released: 08/17/2010;

August 17, 2010 — Acetaminophen use in adolescents is linked to development and/or maintenance of asthma, rhinoconjunctivitis, and eczema, according to the results of a global study reported online August 13 in the American Journal of Respiratory and Critical Care Medicine.

"This study has identified that the reported use of acetaminophen in 13- and 14-year-old adolescent children was associated with an exposure-dependent increased risk of asthma symptoms," said first author Richard W. Beasley, MD, professor of medicine at the Medical Research Institute of New Zealand in Wellington, in a news release, on behalf of the International Study of Asthma and Allergies in Childhood (ISAAC).

At 113 centers throughout 50 countries, 322,959 adolescent children (aged 13 - 14 years) enrolled in ISAAC Phase Three completed written and video questionnaires regarding current symptoms of asthma, rhinoconjunctivitis, and eczema. They also completed a written environmental questionnaire regarding potential risk factors such as acetaminophen exposure in the preceding 12 months. Logistic regression allowed calculation of the odds ratio (OR) of current asthma symptoms associated with acetaminophen use, which was the main study endpoint.

Recent use of acetaminophen was associated with an exposure-dependent greater risk for current asthma symptoms, based on multivariate analyses. For medium use (at least once in the last year) vs no use, the OR was 1.43 (95% confidence interval [CI], 1.33 - 1.53). For high use (at least once in the last month) vs no use, the OR was 2.51 (95% CI, 2.33 - 2.70).

"The overall population attributable risks for current symptoms of severe asthma were around 40 percent, suggesting that if the associations were causal, they would be of major public health significance," Dr. Beasley said. "Randomized controlled trials are now urgently required to investigate this relationship further and to guide the use of antipyretics, not only in children but in pregnancy and adult life."

In multivariate analysis, there was also an acetaminophen exposure–dependent increased risk for current symptoms of rhinoconjunctivitis (OR, 1.38 [95% CI, 1.29 - 1.47] and OR, 2.39 [95% CI, 2.24 - 2.55] for medium and high use, respectively) and eczema (OR, 1.31 [95% CI, 1.21 - 1.42] and OR, 1.99 [95% CI, 1.82 - 2.16] for medium and high use, respectively).

"Acetaminophen use may represent an important risk factor for the development and/or maintenance of asthma, rhinoconjunctivitis and eczema in adolescent children," the study authors write.

An accompanying "at a glance commentary" notes that potential mechanisms for these effects of acetaminophen include oxidant-induced airways inflammation and enhanced Th2 responses.

Limitations of this study include cross-sectional design, precluding determination of causality; and potential confounding factors.

Birth-Cohort Study Also Conducted

Clinical Context

A recent study, published in the current issue of the American Journal of Respiratory and Critical Care Medicine, conducted by Amberbir and colleagues reported that acetaminophen use was associated with increased risk of wheeze, but not eczema, in a small cohort of patients in Ethiopia.

Previously, in 2008, Beasley and colleagues, the current study authors, conducted Phase Three of ISAAC, and in the September 20, 2008, issue of The Lancet, they reported that acetaminophen use (paracetamol) in the first year of life was associated with a greater risk for asthma symptoms in children aged 6 to 7 years.

The current study by Beasley and colleagues uses data from ISAAC Phase Three to evaluate whether acetaminophen use is linked with a greater risk for asthma, allergy, or eczema symptoms in children aged 13 to 14 years.

Clinical Implications

•Recent acetaminophen use is linked with an exposure-dependent increased risk for asthma symptoms in adolescents.
•Recent acetaminophen use is linked with an exposure-dependent increased risk for rhinoconjunctivitis and eczema symptoms in adolescents.