My doctor says Mucinex can cause frequency, urgency of urination. I looked it up and it doesn t list it as a possible side effect. I will be getting a CT scan to see if I have a kidney stone forming. This happened to me last fall. I tested with small amounts of hemoglobin in my urine four different times, but then no infection - UTI per culture so they had me stop taking macrobid. Then January 4th I had terrible pain and a kidney stone. took 28 days to pass it. Not wanting to repeat this. I noticed a link to having sinus trouble that I took Mucinex for per my allergist s recommendation. What effects could Mucinex be having on my kidneys and possible symptoms of UTI or kidney stones?