The state Office of the Child Advocate and the Child Fatality Review Panel issued a Public Health Alert on Thursday regarding the potential danger to infants and toddlers from over-the-counter medication called diphenhydramine, marketed under various trade names such as Benadryl.

Over the last year, four infants and toddlers in Connecticut have died from overdoses of diphenhydramine or other antihistamines, including chlorpheniramine, sold as Chlor-Trimeton, the alert said. Marketed as a treatment for allergies and skin rashes, some parents use diphenhydramine to help their child sleep or to get through a long plane ride or car trip.

Parents and caregivers should never use Benadryl or other antihistamines to get infants and toddlers to be quiet or to sleep, the alert said. These products should be used by young children only when prescribed by a doctor.