If I take 80mg of Oxy (which I'm allowed, if I really need to), I get itchy. I'm sure it's a side effect & not an allergy. I've taken Oxy for awhile so I know I'm not allergic. I recall a friend was given morphine after a c-section one time, & she was really itchy from it. Side effect. Anyway, can you take Benadryl to stop the itchiness, or will it react badly with the Oxy already in your system & knock you out? (or worse, OD) If not Benadryl, then is there anything you can do to stop the itchiness? If anyone knows, thank you! C.