SALURETIC EFFECT OF THE LOOP DIURETIC TORASEMIDE IN CHRONIC-RENAL-FAILURE - INTERDEPENDENCE OF ELECTROLYTE EXCRETION

The effects of torasemide have been studied in 7 healthy controls and 9 patients with stable chronic renal failure of various degrees. After a control period of 3 days torasemide 20 mg i. v. caused a dramatic increase in diuresis and electrolyte excretion without affecting the glomerular filtration rate. The duration of action of torasemide, τ, averaged 6 h and was independent of the creatinine clearance, CLCR. When related to τ the drug-induced excretion of Cl-, Na+, K+, Ca2+ and Mg2+ showed strong linear dependence on CLCR. Both the kaliuresis and the calciuresis during τ were tightly correlated with the natriuresis over the broad range of CLCR. Similarly, the excretion of Mg2+ was dependent on the kaliuresis. The torasemide-induced kaliuresis amounted to 12% of natriuresis, as after furosemide. The kaliuretic effect of loop diuretics is smaller than that of the thiazides. After τ, e. g. over a 24 h period, kaliuresis was not correlated with natriuresis. The magnitude of the rebound effect was diminished with increasing renal impairment. © 1990 Springer-Verlag.