The Ask Dr. Sears site addresses this issue. While they do not recommend Benadryl (diphenhydramine) for infants under 12 months, and at the very bottom of the page, they are kind enough to break down dosage per weight of the child. Benadryl is not generally safe for use in infants under 2, though it can be used under a doctor's orders in infants between 2 and 5. Learn about the safety, risks, and dosages of Benadryl for. Uses. Oral Benadryl products are approved for decreasing symptoms of hay fever and other respiratory allergies, and symptoms of the common cold such as sneezing and runny nose. Benadryl products. Benadryl (diphenhydramine) is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. Explains the medication diphenhydramine (Benadryl), a drug used for the relief of nasal and non-nasal symptoms of various allergic conditions such as seasonal hay fever, allergic conjunctivitis, insomnia, and motion sickness. Find patient medical information for Benadryl Childrens Formula Topical on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. What are the common uses of Benadryl for infants? Pediatricians may recommend you give your baby Benadryl for insect bites, allergic reactions, seasonal allergies, and other allergy-related. Find patient medical information for Benadryl Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. Because of the potential for serious adverse reactions to antihistamines in nursing infants, a decision should be made whether to discontinue nursing or Benadryl (Diphenhydramine), taking into account the importance of the drug to the woman. Benadryl should not be used in neonates and premature infants (see CONTRAINDICATIONS). Benadryl may diminish mental alertness, or, in the young pediatric patient, cause excitation. Overdosage may cause hallucinations, convulsions, or death (see WARNINGS and OVERDOSAGE ).