i started taking toprol about 2 years ago. my doctor started to notice a trace of blood and a small amount of protein in my urine. after a few more urine test over the span of 2 years, the traces of blood would come and go, but the protein levels were rising. eventually i was sent to a kidney specialist. he immediately took me off the toprol. he believes that the toprol may have damaged a filter that goes to both kidneys.he also said that if proteins are getting through the filter there other stuff is getting through too. , which can cause problems in the future.i have an appointment to see him again in 2 months. hopefully not being on this drug anymore, there will be a chance that this filter will heal. if not we are talking biopsies, and kidney drugs. my entire life the only medical problem was my blood pressure, now because of doctors and drugs i may be the sickest i've ever been. somebody said thts why doctors call it a practice, there only practicing