Children who are treated with antibiotics during the first year of life are significantly more likely to develop asthma by age 7, according to a longitudinal cohort study by Canadian researchers (Kozyrskyj A et al. Chest. 2007;131:1753-1759).
In the study, the researchers used a prescription database to monitor the antibiotic use of 13 116 children from birth to age 7 years. They also noted the reasons for antibiotic use and factors known to increase or decrease asthma risk. Compared with children who did not receive antibiotics for nonrespiratory infections in the first year of life, children who did receive the drugs were almost twice as likely to have asthma at age 7. The risk was highest in children who received more than 4 courses of antibiotics, especially those living in households without a dog during their first year.
Stephenson J. Antibiotics and Asthma Risk. JAMA. 2007;298(3):277. doi:10.1001/jama.298.3.277-c