Can chronic opiate abuse/detoxification cause abnormally high creatinine levels?

[Jcred]

I am a 30 year old male who has abused opiates since age 25. During the past year and a half I have had numerous periods of sobriety anywhere from 6 months to 4 months a d 9 months. This last 3 months during a relapse I was using opiates/fentynol everyday. I checked into a detoxification center in which I noticed my creatinine levels were at abnormally high levels, 330.10 mg/dL (if I'm reading this right). Everything I researched about levels this high seemed to point to the worst possible scenario, kidney malfunction, kidney disease, cancer etc. I've always been very active in sports, weight training and even work (never had a desk job). Before this last relapse I sustained 4 months sobriety and I was very physically fit, though I was using over the counter supplements including fat burners (pill form). I had to have lost 20 to 30 pounds most if not all was muscle mass due to malnourishment and dehydration during the 3 months of using. I took this urine test during the detoxification process in which I was very sick, was not eating, drinking or sleeping. I even passed out due blood pressure issue coupled with the lack of food,water and ciggeret smoking. Should I rush to a doctor immediately because of this 330.10 creatinine level? Could any of these other factors cause this high reading? Also, before my opiate abuse began at 25 years of age I did regularly smoke marijuana, occasional use of extacy and cocaine while also taking over he counter muscle building and weight loss supplements. All my blood work and other testing came back healthy or fine as I was told by numerous physicians. This reading has me very concerned cancer absolutely runs in my family and if I need to go directly to a doctor I will do so somebody please help! I did have pain/aching in my back just below my rib cage I'm the past but it was only a handfull of times since the age of 23 and never lasted long and was never a frequent occurrence. Please any input will help maybe even put my mind at ease or point me in the right direction! Thank you!!