 [ Symptoms ] can i give my 2 year old children is benadryl and robitussin cough syrup together [ Disease ] children is benadryl contains diphenhydramine and is labeled for use for children aged 6 and older children is robitussin is available in a variety of different formulations but may contain guaifenesin dextromethorphan andor phenylephrine children is robitussin is labeled for use for children aged 4 and older and in some products aged 6 and older while it is safe to take both the children is benadryl and children is robitussin together i would not recommend these products for your child based on her age