My mother was recently put on macrodantin for a UTI. She has recently developed a rash on her left leg from knee to toes. She also has an infection on her left toe, which her physician stated this drug would help as well. I see that this drug should not be used if person has kidney disease. She is in stage 3 renal failure due to Lupus with increasing BUN levels. Could this drug be responsible for this rash? This has been the only change in her routine. I would appreciate your input