Increased Potassium Loss

Disorders of Potassium Balance Hypokalaemia Increased Potassium Loss

Examples of increased potassium loss are shown in the table:

Example	Specifics
Drugs	Diuretics (loop and thiazide) Laxative abuse Liquorice, steroids
GI losses	Vomiting Diarrhoea Ileostomy Intestinal fistula Villous adenoma
Renal disorders	Barters syndrome Liddle’s syndrome Gitelman’s syndrome Nephrogenic diabetes insipidus type 1 (distal) and type 2 (proximal) renal tubular acidosis
Endocrine	Hyperaldosteronism Cushing’s and Conn’s syndromes
Dialysis
Osmotic diuresis	As occurs in diabetic ketoacidosis

Further information about drugs and GI losses

Diuretics deliver increased loads of sodium and chloride to the distal tubules and thus increase potassium secretion. These drugs also deplete magnesium which leads to further increased potassium loss.

Upper GI losses usually involve small amounts of potassium but the coexistent chloride loss leads to secretion of potassium in the kidney. Potassium is secreted in the distal colon and thus, in ileostomy patients, effluent is not rich in potassium.

Metabolic alkalosis usually develops as a consequence of chloride loss (e.g. by diuretics or vomiting) and in this situation increased delivery of sodium occurs to the distal tubules and this results in increased secretion of potassium into urine.

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