I have been taking beta blockers very long term for the extra heartbeat and palpitations caused by mitral valve prolapse. Now with 50mg/day of atenolol, I have been having painful urination with sometimes cloudy urine. This seems to come on just after I take the medicine, in the evening. I asked my cardiologist and he said that all the beta blockers act similarly, as they lower your blood pressure, this causes the kidneys to release fluid. Could this be part of my problem, or is the beta blocker is just exacerbating another problem, like kidney stones. Has this happened to anyone else?