What are the indications for potassium supplementation in patients with hypokalaemia?

Potassium supplementation is indicated in patients with hypokalaemia when serum potassium concentrations fall below 3.5 mmol/L, even if the patient is asymptomatic but has cardiovascular disease, to prevent adverse events such as ventricular arrhythmias and death. Oral potassium chloride is preferred for supplementation due to its efficacy and lower risk of rebound hyperkalaemia. The target serum potassium concentration is at least 3.5 mmol/L in healthy individuals and at least 4.0 mmol/L in patients with hypertension, cardiac dysrhythmias, or chronic heart failure. Supplementation is particularly important when hypokalaemia is due to increased losses or poor intake. Intravenous potassium supplementation is reserved for severe hypokalaemia (less than 2.5 mmol/L), symptomatic patients (e.g., with dysrhythmias, paralysis, respiratory failure), or when oral supplementation is not tolerated. Additionally, concurrent hypomagnesaemia should be corrected as it impairs potassium repletion. Referral to an endocrinologist is advised if the cause of hypokalaemia is unclear or if oral potassium cannot be tolerated.