6-Aminopenicillanic Acid in Urine after Oral Administration of Penicillins

Abstract

6-Aminopenicillanic acid (6-APA) was detected in the urine after oral and intravenous administration of penicillin G and other known penicillins to mice, and oral administration to rats, dogs, rabbits, and man. After oral administration of penicillin to guinea pigs, 6-APA was not detected in the urine. Tissue macerates of these animals failed to convert penicillin G to 6-APA. Probably, 6-APA in the urine is a result of microbial hydrolytic conversion of penicillin in the intestine and subsequent absorption and excretion.