"i have moderate to severe knee pain; awaiting  knee replacement surgery. i tried lortab 10 mgs but developed allergic reaction (itching). md prescribed panlor ss. i never got the chance to see if it really worked because i also had a reaction to it. the only thing i can figure out is that i have developed an allergy to codeine after all these years at age 52. that is the only common ingredient that i can think of"