Benadryl does not improve infant sleep

Jul 3 2006

An antihistamine often recommended to parents whose infants do not sleep through the night may not be effective in reducing nighttime awakenings or improving parents' happiness with their children's sleep, according to a report in the July issue of Archives of Pediatrics & Adolescent Medicine.

Between 20 and 46 percent of parents have reported that their infants have trouble sleeping, according to background information in the article. Some parents let their children cry for extended periods at night - this method, known as crying out, is popular but controversial among parents and health care professionals. Another commonly used method is to give children medications - such as antihistamines, normally used to treat allergies - to sedate them at bedtime. Diphenhydramine hydrochloride, sold as Benadryl, is often used by parents and recommended by physicians despite the fact that it has not been studied in children younger than age 2 years.

Dan Merenstein, M.D., then at The Johns Hopkins School of Medicine, Baltimore, and now at Georgetown University, Washington, D.C., and colleagues conducted a trial of diphenhydramine in 44 children ages 6 to 15 months who slept in cribs. Parents in the study had all reported that their children woke up two or more times per night. The participating infants were randomly assigned to receive 100 mL of diphenhydramine or placebo (inactive medication) in a cherry-flavored liquid 30 minutes before bedtime for one week between May 2004 and May 2005. Parents reported whether the child had fewer awakenings that required parental intervention during that week and also tracked their child's sleep in a diary for the first 28 days. At four points during the first 43 days of the study, parents were asked to rate their happiness with their children's sleep on a scale of one to 10.

Three of 22 participants in the placebo group and one of 22 participants in the diphenhydramine group had fewer nighttime awakenings during the week in which the infants were taking medication. Two additional parents in the placebo group reported improvement in nighttime awakenings four weeks and six weeks later. There was no difference between the two groups in parents' reports of how happy they were with their children's sleep at any point during the study. On June 6, 2005, the trial was stopped because of the apparent lack of effectiveness of diphenhydramine.

"Many in the medical and lay community accept diphenhydramine as effective treatment for sleep problems," the authors write. "Unfortunately, this attitude is based on anecdote and studies of adult physiological interactions." The results of this study "demonstrated that at the most commonly used dose, diphenhydramine may play no role in treating infant sleep problems."

More rigorous studies are needed regarding effective treatment for sleep problems in children, the authors conclude. "Important aspects of a young child's health care, such as proper food intake and sleep routine, often are based on assumptions," they write. "Our study results illustrate that such assumptions may be wrong and should be subjected to study in life laboratories."