Although some clinical studies seem to prove the efficacy of nonantialdosteronic
potassium-sparing diuretics in the treatment of
ascites, no controlled study has compared the efficacy of these drugs with that of antialdosteronic
diuretics. Forty nonazotemic cirrhotic patients were randomized to receive
amiloride (group A, n = 20) or
potassium canrenoate (group B, n = 20). The initial doses of
amiloride and
potassium canrenoate were 20 mg and 150 mg, respectively. The doses were increased in stepwise fashion to 60 and 500 mg/day, respectively, if no response 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, whereas only two of the nonresponders to
potassium canrenoate later responded to
amiloride. The
diuretic responses to
amiloride and
potassium canrenoate were related to the activity of the
renin-
aldosterone system. All responders to
amiloride (n = 9) had normal values of plasma
aldosterone. All nonresponders to
amiloride who later responded to
potassium canrenoate (n = 7) had increased levels of plasma
aldosterone. Moreover, 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 distal tubule) was found to be the main difference.(ABSTRACT TRUNCATED AT 250 WORDS)