Abstract
In a recent paper in the BMJ, Lund et al reported an increased risk of infantile hypertrophic pyloric stenosis (IHPS) in infants exposed to macrolides, especially during days 0-13 (adjusted rate ratio (ARR)=29.8, 95%CI=16.4-54.1). The excess risk decreased rapidly with exposure later in life (days 14-120: ARR=3.24; 95%CI=1.20-8.74). Also a retrospective cohort study of children to US uniformed personnel recorded in the TRICARE database found a positive association between macrolides and IHPS. In Sweden, one of the most common uses of erythromycin in newborns is to stimulate the gastrointestinal motility and we believe that the positive association between macrolides and IHPS is due to reverse causation. Lund et al also mention that some macrolides are used for dysmotility in smaller children.
In a nationwide cohort of 582,494 children born between July 2005 and December 2010 in Sweden we examined the use of macrolides and the risk of IHPS.