Concentration of Streptomycin in Brain and Other Tissues of Cats After Acute and Chronic Intoxication.∗

Summary Streptomycin was found in the brain, lungs and liver of cats for as long as 3 days after a single injection of 400 mg per kg. At this time the drug had virtually disappeared from the blood and CSF. The concentration in the brain was small compared with that in the other organs. In cats showing typical chronic intoxication during treatment with streptomycin in daily doses of 100 mg per kg, no accumulation of the drug was found in the serum, CSF or brain 24 hours after last dose. Significant concentrations of the drug were present in other tissues, especially in the kidney. It is concluded that the chronic neurotoxic action of streptomycin cannot be attributed to accumulation of the drug in the brain as a whole or in the brain stem.