I wanted to post this because I am surprised at how many providers, both novice and experienced of all levels, have the misconception over sulfa allergy and morphine. Sulfa allergy relates to medications know as sulfonamides which are largely a group of antibiotics (Bactrim). Furosimide (Lasix) is also in this class as well. Morphine Sulfate is NOT a sulfonamide so if a patient say's they have a sulfa allergy, they CAN have Morphine. I was with a preceptor one time and we had a fall patient having some pain who said she had a sulfa allergy. My preceptor then went on to tell the patient that the only med we had for pain was morphine of which the patient couldn't have due to her sulfa allergy. As a student I didnt want to correct my preceptor.