Can i give my 12 yr old robutussin cf and benadryl (diphenhydramine) together?

Cough medicine : No you can't, but you can use plain Robitussin or Robitussin DM with benadryl (diphenhydramine). I hope that helps.

No.: Benadryl (diphenhydramine) is only useful if having allergic symptoms. Over the counter cough and cold remedies make kids feel worse, prolong their symptoms and increase the risk of secondary bacterial infections like pneumonia and otitis media. They have been proven ineffective for years and years, but we can't compete with commercials. See Cochrane reviews (independent researchers) http://tinyurl.com/osmaxzo