RANDOMIZED CLINICAL-STUDY OF THE EFFICACY OF AMILORIDE AND POTASSIUM-CANRENOATE IN NONAZOTEMIC CIRRHOTIC-PATIENTS WITH ASCITES

Although some clinical studies seem to prove the efficacy of nonantial dosteronic potassium-sparing diuretics in the treatment of ascites, no controlled study has compared the efficacy of these drugs with that o f antialdosteronic diuretics. Forty nonazotemic cirrhotic patients wer e randomized to receive amiloride (group A, n = 20) or potassium canre noate (group B, n = 20). The initial doses of amiloride and potassium canrenoate were 20 mg and 150 mg, respectively. The doses were increas ed in stepwise fashion to 60 and 500 mg/day, respectively, if no respo nse ensued. Nonresponders to the highest doses of each drug were later treated with potassium canrenoate and amiloride, respectively. Seven of 20 group A patients responded to amiloride, whereas 14 of 20 group B patients responded to potassium canrenoate (p < 0.025). Seven of 13 nonresponders to amiloride later responded to potassium canrenoate, wh ereas only two of the nonresponders to potassium canrenoate later resp onded to amiloride. The diuretic responses to amiloride and potassium canrenoate were related to the activity of the renin-aldosterone syste m. All responders to amiloride (n = 9) had normal values of plasma ald osterone. All nonresponders to amiloride who later responded to potass ium canrenoate (n = 7) had increased levels of plasma aldosterone. Mor eover, on comparison of all responders (n = 21) and nonresponders (n = 12) to potassium canrenoate, a higher degree of renal proximal sodium reabsorption (with consequent limitation of sodium delivery to the di stal tubule) was found to be the main difference. These results indica te that (a) amiloride is less effective than potassium canrenoate in t he treatment of ascites in cirrhotic patients and (b) amiloride may re present an alternative to potassium canrenoate only in patients withou t increased activity of the renin-aldosterone system.