Studies have shown that substantial amounts of furosemide (F) bind to urinary protein in animals with nephrotic syndrome (NS) making the diuretic inactive. In these models, displacement of F from binding sites by sulfisoxazole (S) restores F's diuretic effectiveness. The current study was designed to determine if this occurs in humans and if so whether using S in patients with NS might be a helpful therapeutic strategy. Seven (4 males, 3 females) patient volunteers with NS between the ages of 20-60yrs participated in a randomized, placebo-controlled, crossover study investigating the effect of S on F pharmacodynamics. After achieving sodium (Na+) balance volunteers received S (2 grams Q8H × 3 doses) or placebo orally followed by an IV infusion of F (120 mg over 30min). Serum and urine samples were obtained and F, S, Na+ and potassium (K+) concentrations were determined by HPLC or flame-photometry. The results of the study are given in the Table. In conclusion, unlike the effects of S on F in animal models with NS, S does not increase the efficacy of F in patients with NS. Total Na+ Total K+ Total F Weight Excretion Excretion Excretion N (Kg) (mmol) (mmol) (mg) F alone 7 99±21 239±90 31±5 50±15 F+S 7 99±21 231±125 31±10 50±15.
ASJC Scopus subject areas
- Pharmacology (medical)