Potassium metabolism and diuretics administration in liver cirrhosis

The author first reviews, on the basis of personal and literature data, the main changes in three major parameters of potassium metabolism: serum potassium; daily urinary output of potassium; exchangeable potassium (Ke) at the three stages of the course of liver cirrhosis. The action of K-sparing diuretics (spironolactone, triamterene, amiloride) on these parameters is analysed. Although the introduction of these diuretics in our therapeutic armamentarium has resulted in a major advance, i.e. the quasi-total elimination of iatrogenic hypokalaemia and hypokalaemia-induced portacaval encephalopathy in the cirrhotic, the limits of their action on K metabolism are underlined: they may moderately enhance urinary K output; following cessation of their administration, a ‘rebound’ in urinary K output may be noted. Finally, Ke may still continue to decrease during their administration, indicating an aggravation of the underlying disease. It was also found that a rise in serum K and/or Ke during amiloride administration did not prevent the elevation of plasma renin activity usually induced by volume and/or Na depletion.