Acetaminophen (Tylenol, Feverall, Tempra) is used to relieve fever and pain. Please call if your infant is less than 2 months and has fever. The infant & children's syrup is the same concentration and therefore would be the same dosing.
Ibuprofen (Motrin, Advil) is used to relieve fever and pain. It is NOT indicated for infants less than 6 months old. The infant & children's syrup have different concentrations. Therefore, pay close attention to which which formulation you have to dose accordingly.
Diphenhydramine (Benadryl) is used to treat allergic reactions, itchiness, nasal allergies and hives. Avoid under 6 years of age unless directed by physician. Non-sedating alternatives such as loratadine, cetirizine and fexofenadine can be used safely down to 6 months of age.
This is a great tool to assess if a symptom or sign your child has should be checked out or watchful waiting is reasonable.