Hi i am Dr Ahmed Aly thanks for using healthcaremagic site , I had gone through your question and understand your concerns .. In my opinion i may suggest topical antihistaminics for your rash will be fine as the tablet forms may increase your sleeping time when used with tramadol . but if persists i recommend stopping tramadol and taking another long acting analgesics like advil , ibuprofen , gabapentin . You may discuss the dosage with your specialist according to your history of arithritis or you may decrease the dose of your tramadol and use only when needed as it is a pain killer not a treatment . Please click and consider a 5 star rating with some positive feedback if the information was helpful. Wish you good health, Any further clarifications feel free to ask.