Skeletal muscle loss/ischemia evident by high myoglobin in urine (25). what are the markers for myalgia vs neuropathy? patient on gabapentin and decreased gfr (20), cymbalta was discontinued for low gfr. which specialist would be best for the issue?

Complex issue.: You're asking a very complex question. As far as a specialist is concerned, I feel a Rheumatologist would serve you best given your questions and considerations.

Need more informatio: What are the muscle enzymes CPK and Aldolase. Are they elevated sicne there is urine myoglobin. If the myoglobin is elevated this suggests that the myalgia may be a myositis. Neuropathy is something different. Ask your physician about seeing a neurologist for the neuropathy and a nephrologist for the kidney. You may need others.

Concerns.: Usually urine myoglobin levels indicate rhabdomyolysis, which may well indicate a primary inflammatory muscle disease. Although basic CK and aldolase measures might help, you may well require EMG and even muscle biopsy. The presence of kidney failure raises concern for many systemic disorders. I think a nephrologist is a very good starting point.