Hello, I am looking for some thoughts/advice. My husband, 38 yrs old, not overweight, exercises regularly. He is not diabetic and does not have high blood pressure. He was diagnosed with a pituitary tumor 15 yrs ago so he gets full blood work every 6 months. Nothing has changed in his diet or his medications. No urinary symptoms. Drinks water all day except for his coffee in the morning. In August 2015 his lab result showed his Creatinine elevated at 1.46 (range 0.60-1.35). He was taking a lot of Advil at the time and we found out that could have been the cause so he ended up going to a Nephrologist in November 2015. She was pretty sure his elevated creatinine was not CKD. She ordered a 24 hr urine test (creatinine clearance) and it came back normal. The results were a 2.00 (range 0.63-2.50 g/24 h). She said this means his GFR is over 100% and his kidneys were functioning normally. At the time of the urine test his creatinine was a 1.33 (it did lower from the 1.46 in August 2015). My husband is a pretty big guy and she kept blaming his size for the elevated creatinine although he’s been bigger than average his entire life, he actually worked out and had more muscle mass when the creatinine was 1.2. but we felt reassured he was ok. Then he had his bi-annual bloodwork done for his tumor in Jan. 2016. His creatinine was a 1.22. We were very relieved and were sure it was from all the Advil and he was back to what he was the year prior and before that… a pretty steady 1.2 His recent bi-annual bloodwork 10/27 was just completed and his creatinine is back up to 1.39. What would cause this increase again? Nothing has changed. I’ve read all about eating too much protein, dehydration, high blood pressure but again there’s been no change in anything. Can antibiotics raise creatinine? He was on a 3 month course of Doxycycline (tetracycline class antibiotic) for Rosacea. He stopped taking it at the end of July. It really upset his stomach. Bad cramping,diarrhea. Could this have increased his creatinine? Even though he stopped it 3 months ago? I can’t think of anything else that would have raised it from a 1.22 to a 1.39. Any advice would be appreciated. I will be calling the Nephrologist tomorrow to possibly repeat the test.

I’m not sure there is any way to answer your question.  The serum creatinine has many factors that can affect an individual test including variability in the individual blood testing, dehydration, medications, diet and many other factors.  You have mentioned many of these factors that may all have an effect.  I can only suggest continued observation and leading a healthy life-style.  I suggest that you discuss your concerns with his nephrologist and try to understand the testing that has been done and further testing that could be done to clarify the issue.


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