Erythromycin Treatment Associated with Infantile Hypertrophic Pyloric Stenosis

As referenced in: MMWR 48(49);1117-1120

Erythromycin prophylaxis of newborns with possible exposure to pertussis in a newborn nursery was strongly associated with subsequent increased incidence of infantile hypertrophic pyloric stenosis (IHPS) in a Knoxville, Tennessee, hospital. The increase in IHPS was noted by pediatric surgeons in the area and the association established during an investigation conducted by the CDC Division of Birth Defects and Developmental Disabilities. The results of the investigation are reported in the December 17, 1999 issue of the CDC Morbidity and Mortality Weekly Report and in the December 18, 1999 issue of The Lancet.Staff in the Division of STD Prevention, NCHSTP, CDC, reviewed the 1998 Guidelines for the Treatment of Sexually Transmitted Diseases to identify recommendations for treatment of newborns that are potentially affected by the finding. The principal such recommendation is for the use of erythromycin to treat ophthalmia neonatorum and infant pneumonia caused by Chlamydia trachomatis. Monitoring rather than prophylactic treatment is recommended for infants born to women with C. trachomatis infection at delivery. Concern is heightened by the lack of alternative antibiotics with established efficacy and safety for treatment of young infants with C. trachomatis infection. The number of infants in the investigation who developed IHPS following erythromycin was small (7), accounting for 4.5% of those receiving erythromycin, but the strength of the association was strong and the timing of the exposure and recognized actions of erythromycin on the pylorus establish biological plausibility. Since confirmation of erythromycin as a contributor to cases of IHPS will require additional investigation and alternative therapies are not available, CDC continues to recommend use of erythromycin as described in the 1998 Guidelines for treatment of C. trachomatis infections in infants. However, readers responsible for treating such infants are strongly encouraged to review the MMWR report. Cases of IHPS diagnosed following use of oral erythromycin should be reported to the Food and Drug Administration (FDA) as described in the MMWR report. Investigation of other antibiotics to develop alternatives is also warranted. Newer macrolides have a lower rate of gastrointestinal side effects in adults, but they are not FDA-approved for treatment of infants under 6 months of age, and their efficacy and side effects compared with erythromycin need to be established before revision of current CDC recommendations for use of erythromycin would be indicated. It should be emphasized that the need for treatment of infants can be avoided by screening pregnant women to detect and treat C. trachomatis infection prior to delivery.