I have been allergic to opioids. However, I just got Tylenol with Codeine today. Took the first pill tonight and after 3 hours, I don t seem to be having an allergic reaction. Is this a normal exception for a person who got terrible hives ad rashes to Vicodin, Percocet and Hydrocodone previously? Oh, I was diagnosed with a pinched nerve in back a few years ago.