Can you give a child benadryl (diphenhydramine) and sudafed at the same time?

Avoid decongestants: Pseudoephedrine (sudafed) can cause irritability and high blood pressure in children but doesn't seem to actually help with congestion until puberty. Sudafed-pe (phenylephrine) has the same issues but typically is very poorly absorbed into the body. These drugs should never be given to children given the potential harm and lack of benefit. Benadryl should be limited to once a day during a cold.