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. Reduction of potassium concentrations in the extracellular space leads to cell repolarization. A slight variations in plasma potassium concentration may reflect a significant changes in the systemic content of this cation. The daily intake of potassium is 20‒100 mmol. In subjects with normal kidney function, the majority of dietary potassium is excreted in the urine.
Hypokalemia is defined usually as a reduction of plasma potassium concentration below 3.5 mmol/l. Hypokalemia is predominantly caused by the use of thiazide and thiazide-like diuretics, loop diuretics, primary hyperaldosteronism, or the consumption of licorice-containing products. The mechanism leading to hypokalemia in these clinical conditions is an excessive loss of potassium in the urine.
In order to reduce the risk of hypokalemia and its complications, patients should be informed of their symptoms and the plasma potassium concentration should be monitored in all patients with increased risk of hypokalemia.