IN-VIVO CLEARANCE STUDY OF VANCOMYCIN IN RATS

The renal handling of vancomycin in rats and the effects of various dr ugs (probenecid, cimetidine and quinidine) on urinary excretion of the antibiotic were investigated by in-vivo clearance. The vancomycin-to- inulin excretion ratio (ER) was greater than unity at various infusion rates-of vancomycin. Quinidine, co-administered with vancomycin, sign ificantly decreased the total, renal and net secretory clearance of th e antibiotic. Cimetidine also decreased, though not significantly, the secretory clearance of vancomycin by about 20%, but probenecid did no t. These results suggested that vancomycin is secreted in renal tubule s in rats, and that quinidine decreases the total clearance of vancomy cin partly by inhibiting its tubular secretion in the kidney.