NR3C2 and Hyperkalemia: A higher frequency of peritonitis was foundin patients treated with spironolactone, but this would seem to be an incidentalresult, since there is no justification for such a finding in the literature.38-40 The most dreaded adverse effect of spironolactone is hyperkalemia.Aldosterone increases renal excretion of potassium and thus patients on dialysiswith urinary output may develop hyperkalemia when using MR antagonists.