THE RENAL EXCRETION OF 4'-CARBOXYPHENYLMETHANE SULFONANILIDE (CARONAMIDE)

¹ Research Service, Third (New York University) Medical Division, Goldwater Memorial Hospital, Welfare Island, New York, New York; Department of Medicine, New York University College of Medicine, New York, New York

1. Forty per cent of caronamide in dog plasma is bound on plasma protein at a drug concentration of 10 mgm. per cent and an albumin content of 3.5 gram^s per cent.

2. The overall renal clearance of caronamide in the dog is approximately one-half the filtration rate.

3. The average ratio of the clearance of caronamide, corrected for plasma binding, to glomerular filtration rate in 3 dogs is 1.30. The excretion of caronamide, therefore, is the result both of glomerular filtration and of some renal tubular excretion.

4. Evidence is presented for the occurrence of a metabolic product of caronamide in the plasma of 3 dogs, and in the urine of 2 of the 3 dogs.

5. Fifty-nine per cent of administered caronamide was recovered in the urine in a single experiment as caronamide. There was also evidence of an appreciable amount of caronamide metabolic product in the urine.