What is causing an allergic reaction?

How do I know if my pain meds are causing an allergic reaction?

• I was in a car accident recently and had two plates and multiple screws put in my left ankle and was also diagnosed with three herniated discs in my cervical spine. I was previously on vicodin 10/325 and the doctor changed it to percocet 10/325 (4x a day as needed) and opana 30er. My insurance was cancelled when I lost my job and I was given 90 days of roxicodone 30 until I could get a new job and insurance. I just got two scripts, 30er and percocet 10/325 (4x a day as needed). When I went to fill them I was shocked to find there wasn't a single pharmacy within 60 miles of miami (north & south) that had either medicine in stock . I placed the order through my cvs mail order pharmacy. Upon receipt of the order the percocet looked exactly how I remembered (generic watson) .. however the Opana was vastly different. After doing research I found the makers of Opana pulled the previous formula and released a design that is tamperproof (i.e. you can't crush and snort or smoke or stick in your butt) which didn't bother me because I am fine with taking as prescibed. Within 12 hrs I was not in pain but I was itchy worse than any opiate ever made me. I went to work the next day and was so warm I was uncomfortable (suit & tie) and my coworkers commented that it looked like I had hives on my face. It was red / splotchy and itchy. By the end of the day I was itching even worse than before and succumbed to the temptation and scratched . The next day I was barely able to get out of bed I was so uncomfortable - felt like the worst case of sunburn ever. I noticed that the areas that were very red also had deep scratches. Either I did this in my sleep or just didnt feel it due to the medicine releiving pain. At work I was absolutely miserable. (but not in pain other than the annoying scratches and incessent itchy feeling.) After work it was worse looking but nothing raised. I have in the past gotten heat bumps completely unrelated to this injury but I wondered if the opana or percocet were just making me normal opiate itchyness which turned bad when i scratched everywhere irritating these heat bumps? usually i wouldn't touch them and they would just go away. Which in my case I was so itchy I just scratched and now I (hope) I just have contact demititas or something minor. I also thought - a. the opana and its new formula just made me a statistic and I am allergic, or b. the percocet was either expired or contaminated. I can't see going from oxycodone 30mg (roxicodone) 4 x a day to suddenly being allergic to them but i suppose anything is possible.. At this point I do not want to rush to the emergency room just because i scratched an itch too much.. I have flushing in my face (nose especially and forehead,) neck and upper torso, arms (none on hands so far) stomach, back (both sides very bad ** where I couldn't reach to scratch is not bad at all) very bad on my butt, (nothing on my genitals) , thighs, calves, and feet not the soles. Yesterday I bought cortizone cream which brought some relief, finally., It was used up last night and I was unable to sleep (the opana is not working like I remember ' it almost makes me manic.) I tried calling my doctor and he has not called back. I do NOT want to go to the ER, they label you as a junkie/drug seeker, and you end up sitting for hours. The pharmacist said that it sounds like an allergic reaction and just stop the meds all together for 2 weeks and only then would we know for sure. I can't just stop my pain meds and hope that I'm not allergic. I would really like to think that the opana and percocet caused itching, FLorida heat & humidity,played a role and my scratching just made it all disasterous. I was told HURRY!! RUSH TO THE ER!!! .. but isn't that a little dramatic? My breathing is fine and I have no chest pain but the itchyness is driving me crazy and making me miserable and irritable. Anyone have experience with this? Advice? I follow my prescriptions and don't stick pills in my butt or nose, or veins. Help!! ASAP 5/26/12 -- what should i do!!

• Answer:

  Do an experiment. Take 50mg of Benadryl (diphenhydramine) and see if the symptoms get better. (Benadryl is an antihistamine, as you probably know.) That might indicate if the reaction is atopic (allergy-based) or not. As you said in your post, opiates do cause a release of histamine which can cause quite severe itching and hives. The thing to watch out for is further allergic symptoms--bronchospasm (difficulty breathing), and low blood pressure, which can lead to dizziness and shock.