Cirrhosis and muscle cramps: evidence of a causal relationship.

The aim of the study was to define the features, prevalence, and pathophysiology of therapy for muscle cramps in cirrhotic patients. The first protocol study included 294 cirrhotic patients and 194 age- and sex-matched controls. Controls were defined as inpatients or outpatients without any clinical and laboratory evidence of liver disease. Features and prevalence of muscle cramps were defined on the basis of a standard questionnaire. As far as the pathophysiological associations of muscle cramps were concerned, the following parameters were evaluated: mean arterial pressure (MAP), nutritional status, liver function tests, plasma volume (PV), plasma renin activity (PRA), and electrolyte, mineral, and acid-base status. The prevalence of cramps was higher in cirrhotic patients than in controls, and it was related to the duration of recognized cirrhosis and to the severity of liver function impairment. At a multiple regression analysis, the presence of ascites, low values of MAP, and high values of PRA were the independent predictive factors for the occurrence of cramps in cirrhosis. In the second protocol study, the effects of a sustained expansion of the effective circulating volume induced by intravenous infusion of human albumin were compared with those of a placebo in 12 cirrhotic patients with more than three cramp crises a week. Compared with the placebo, albumin reduced the cramp frequency (P < .01). In conclusion, an increased prevalence of true muscle cramps occurs in patients with cirrhosis. Our data indicate that the pathophysiological link between cirrhosis and cramps may be represented by the reduction of the effective circulating volume. They also indicate that weekly infusion of human albumin may be an effective treatment for cramps in cirrhosis.

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 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)

Effects of amiloride on renal lithium handling in nonazotemic ascitic cirrhotic patients with avid sodium retention.

The reliability of lithium clearance as an index of distal fluid delivery in cirrhosis with ascites and in other clinical conditions characterized by low fractional sodium excretion has not yet been proven. In particular, lithium reabsorption in the amiloride-sensitive segment of the distal tubule, as evidenced in experimental studies, has not been excluded in such clinical conditions. Thus the acute effect of amiloride on renal lithium handling in 15 nonazotemic ascitic cirrhotic patients with avid sodium retention was evaluated after at least 5 days of controlled sodium intake. Renal plasma flow, glomerular filtration rate, fractional sodium excretion, fractional lithium excretion, fractional potassium excretion, fractional excretion of uric acid, plasma renin activity, plasma aldosterone and human atrial natriuretic peptide were evaluated before and for 6 hr after the administration of amiloride (20 mg/os). After amiloride administration a volume replacement scheme was enacted with intravenous amounts of saline solution, determined by the diuretic and natriuretic effect of the drug, to avoid volume depletion. Amiloride induced a prompt and sustained increase in fractional sodium excretion (from 0.28% +/- 0.09% to 1.0% +/- 0.41%, p less than 0.001) and a decrease in fractional potassium excretion (from 9.38% +/- 5.98% to 3.28% +/- 2.24%, p less than 0.0025), whereas it did not affect fractional lithium excretion and fractional excretion of uric acid. No change was observed in renal plasma flow, glomerular filtration rate, plasma renin activity, plasma aldosterone and human atrial natriuretic peptide. It was concluded that lithium is not reabsorbed in the amiloride-sensitive segment of the distal tubule in nonazotemic ascitic cirrhotic patients with avid sodium retention.