Increased toxicity of oral antibiotics in sodium-deficient rats.

The toxicity of an oral antibiotic mixture used to decontaminate the gastrointestinal tract of experimental animals was compared in rats with a normal sodium intake to rats on a sodium-deficient diet. Sodium-depleted rats are quite sensitive to the oral antibiotic mixture. The antibiotic mixture was nephrotoxic, resulting in necrosis of the proximal tubules. Therefore, since the parenteral administration of antibiotics also produced necrosis of the proximal tubules, the mechanism of antibiotic toxicity in sodium-deficient rats is not influenced by the route of antibiotic administration.