Yes I have lost a significant amount of weight , and my sternum is per trudging out really far, I have never seen this before. My doctor said it was probably hereditary. I am on a 75 mg fentanyl and percocets for a failed back,surgery and have taken the meds for over 5 yrs. I have a very small appetite and force myself to eat. I have noticed I have a better appetite when I have just put a patch on maybe 2 to 10 hrs after. I had blood, urine , and X-rays don recently to check my situation. My doc said my blood count was just a tiny bit low but not enough to be alarmed. I am under a lot of stress too. I am 6,1 39 years old and I am down to around 150 pounds now, and I seem to Los 2 to 5 pounds every month for the last 3 years. I have gone from a size 38 waiste to a 32 and I am just concerned that the back pain could be a misdiagnosis ?thanks for any ideas