ASSESSMENT OF THE TUBULAR HANDLING OF POTASSIUM IN CIRRHOTIC PATIENTS TREATED WITH A COMBINATION OF FUROSEMIDE + SPIRONOLACTONE

Cirrhotic patients develop hyperaldosteronism secondary to advanced stages of their illness and require treatment with furosemide + spironolactone. The tubular handling of potassium (K) in this patients under such combined diuretic scheme (antagonic) had not yet been studied, therefore we decided to document in an original way the net effect, in this pharmacological context, of the renal potassium handling assessed by means of two specific indicators for that purpose: the fractional excretion of potassium (FEK) and the trastubular potassium gradient (TTKG). Material and Method: The FE of sodium (Na), FEK and TTKG were assessed in 18 patients (11 men), with an average age of 56, normokalemic, suffering from compensated cirrhosis (Ci) stages Child Pugh A, B and C, MELD 22, having normal glomerular filtration, urinary sediment and renal ultrasound, treated with furosemide (average dose: 40 mg/day) + spironolactone (average dose: 100 mg/day) and on hyposodic diet. The control group consisted of 10 healthy volunteers under the same diet (S). For the statistical analysis of the data, the non-parametric test Wilcoxon was applied. Results: Kalemia (mmol/l): 4 ± 0.5 (Ci) vs. 4 ± 0.3 (S), p=NS; FENa (%): 0.8 ± 0.4 (Ci) vs. 0.5 ± 0.3 (S) p=NS; FEK (%): 9.1 ± 3 (Ci) vs. 10 ± 2 (S), p=NS; TTKG: 6 ± 2 (Ci) vs. 4 ± 1 (S), p=0.04. Conclusion: It was documented a significant urinary potassium excretion increase in cirrhotic patients on furosemide + spironolactone, only detected by the TTKG.