If I were to take 120 mg codeine + 1/2 a benadryl, would this be a bad idea? I've never really used any big dosage of codeine, maybe only up to 10 mg. I was told 90 mg won't do anything and I should feel good at 120 mg. Only post if you know FOR SURE. Update: Not Vicodin, Tylenol 3 for me....