Switching Between Antibiotics Among Danish Children 0-4 Years of Age: A Nationwide Drug Utilization Study

In Denmark, the use of amoxicillin is widespread among children, despite phenoxymethylpenicillin being recommended as first-line therapy. The reason for this apparent discrepancy is not fully understood. We aimed at evaluating prescribing patterns of antibiotics among Danish children 0-4 years of age, with emphasis on incidence of treatment episodes, choice of initial antibiotic treatment and switching patterns between different types of antibiotics.

We identified all children ≤4 years of age who filled a prescription of antibiotics from 2000 to 2015 according to the nationwide Danish National Prescription Registry. We estimated the incidence rate of episodes treated with antibiotics and the choice of initial antibiotic treatment over time. Further, we assessed the cumulative risk of switching within 0-3 days after initiating therapy.

We identified 3,481,684 antibiotic treatment episodes issued to 0- to 4-year-olds from 2000 to 2015. The incidence rate was stable until 2011 both among children 0-1 years of age (approximately 880/1000) and among children 2-4 years of age (approximately 610/1000), after which it dropped. Phenoxymethylpenicillin and, increasingly, amoxicillin were most frequently used as initial treatments (39% vs. 44%). Few switched from amoxicillin (1%) or phenoxymethylpenicillin (4.7%) within the first 3 days. Of those who switched from phenoxymethylpenicillin, 64% received amoxicillin as second-line treatment.

The incidence of episodes treated with antibiotics among Danish children 0-4 years of age has decreased considerably since 2011. In contrast to guideline recommendations, amoxicillin is the most frequently used initial treatment. Early switching between antibiotics is uncommon. Initiatives should address the extensive use of amoxicillin.