Potassium is the principal intracellular cation and a critical determinant of cellular membrane potential, essential for normal neuromuscular transmission and cardiac electrophysiology. Even modest reductions in extracellular potassium can impair myocardial excitability and increase the risk of conduction abnormalities and life-threatening arrhythmias.
Thiazide and loop diuretics, widely used in the management of hypertension and heart failure, promote renal potassium wasting and are among the most common pharmacological causes of hypokalemia. Diuretic-induced hypokalemia may be asymptomatic or present with muscle weakness, electrocardiographic changes, and increased cardiovascular risk.