Can i give my 4 yr old adult benadryl (diphenhydramine) if i give her 1/2 of a pill?

Mgt: For use as an antihistamine, it is better to give children's syrup. Cutting the pill in half will not result in an accurate amount. Children need dosing per their body weight. Children's Claritin (loratadine) has fewer side effects.

If she'll take it: Pill cutters are not very accurate and most of these tabs are not scored for cutting, however, at that age it might work in a pinch. Most tablets are 25mg which would me more than most 4 yo would need, a true half would be a little less.Sedation is likely whatever the dose.