I got my Oxycontin field this morning from the drugstore and they are differing it has OP on the. backside, but I don't think they worked as good as the OC's did, I think the pharmacy gave me a generic medication . I'm giving it few days I am on 80 mg three times a day. Do you think the pharmacy made a mistake? This is my first time post I don't understand the difference in this medication can someone please explain it to me,