Summary: Potassium is the main intracellular cation involved in the regulation of the resting potential of cells and thus regulating their ability to stimulate and conduct impulses. The concentration of potassium increase in the extracellular space leads to the resting potential of cell membranes reduction by impairing the formation and propagation of impulses. Daily potassium intake is 20‒100 mmol. In subjects with normal kidney function the majority of dietary potassium is excreted in the urine. Hyperkalemia is defined as an increase in plasma or in blood potassium concentration above 5.0 mmol/l. Hyperkalemia is, among others, a complication of the use of drugs that reduce renin synthesis in the juxtaglomerular cells, angiotensin converting enzyme inhibitors, angiotensin receptor antagonists, drugs that decrease the synthesis of aldosterone, blockers of mineralocorticoid receptor and reducing the activity of the epithelial sodium channel agents and drugs that reduce the amount of sodium reaching the collecting duct, as well as, calcineurin inhibitors. In addition, hyperkalemia occurs in patients with chronic kidney disease and acute kidney injury and also in patients with adrenal gland insufficiency, metabolic acidosis, haemolysis or crush syndrome (rhabdomyolysis).
To reduce the risk of hyperkalemia first of all it is necessary to reduce potassium in the diet and to eliminate drugs which decrease potassium excretion with the urine in patients with impaired kidney function or aldosterone deficiency. Additionally, patients should be informed about clinical symptoms of hyperkalemia and plasma potassium concentration should be monitored in all patients at increased hyperkalemia risk.