Erythromycin and risk of infantile pyloric stenosis

Advice for healthcare professionals:

• an increased risk of infantile hypertrophic pyloric stenosis following exposure to erythromycin in infancy has been reflected in the product information for some time
• data from three recent meta-analyses has led to updates for the magnitude of increased risk with erythromycin use during infancy in general, and to reflect that the risk is highest in the first 14 days after birth
• consider the benefit of erythromycin therapy against the potential risk of developing infantile hypertrophic pyloric stenosis
• advise parents to seek advice from their doctor if vomiting or irritability with feeding occurs in infants during treatment with erythromycin

Notes:

• the background incidence of infantile hypertrophic pyloric stenosis is thought to be 0.1–0.2% livebirths. The studies show that the risk of infantile hypertrophic pyloric stenosis following exposure to erythromycin is highest in the first 14 days after birth. Available data suggests an incidence of 2.6% (95% CI 1.5 to 4.2) for infants younger than 14 days following exposure to erythromycin
• the studies suggest an overall 2–3-fold increase in risk of infantile hypertrophic pyloric stenosis following exposure to erythromycin in infancy in general.

Reference:

• Drug Safety Update volume 14, issue 5: December 2020: 3.