[Effect of aztreonam on bacterial flora in human feces]

Aztreonam (AZT), a new injectable monobactam antibiotic, was administered to 7 healthy male volunteers, aged 21-28 years (23 years, on average) and weighing 60.5-87.0 kg, (69.5 kg, on average) by one shot intravenous injection of 1,000 mg twice a day for 5 days. The effect of AZT on the fecal flora was studied 3 days before administration, on the day of the initiation, 3 and 5 days (end of the administration course) after the initiation, and 3, 5 and 10 days after the end of the administration. Fecal concentration of AZT was also studied. Also, fecal concentration and recovery rate of AZT in 4 healthy male volunteers aged 23-31 years (26 years, on average), weighing 59.5-70.5 kg (65.6 kg, on average) were measured by injecting 1,000 mg of AZT by intravenous injection only one time. Susceptibility of the bacteria isolated from the 7 cases receiving consecutive dosage to AZT, cefmetazole (CMZ), latamoxef (LMOX), cefoperazone (CPZ) and ceftazidime (CAZ) as well as side effect and laboratory values were examined with the following results. In the fecal flora, the population of Enterobacteriaceae on average was 10(7) cells/g feces on the day of the initiation and decreased by 2 logarithms to 10(5) cells/g 3 days after the initiation, 10(5) cells/g feces 5 days after the initiation with no bacterial isolation in 2 cases, 10(7) cells/g feces on 3 and 5 days after the end of administration respectively with recovery of the population to the average population on the day of the initiation. However, it increased 10 days after the end of administration with the population of 10(9) cells/g feces due to the isolation of one 10(10) cells/g feces, which was an increase by 2 logarithms as compared with average population before the administration. It was also higher than the average population 3 days before the initiation of administration. Temporal decrease or disappearance of the bacteria were noted by the administration of AZT. As to other cases of Gram-negative bacilli, Pseudomonas sp. was detected from only 2 cases 3 days before the initiation of administration and on the day of the initiation, but there was an increase to 4 and 5 cases 3 and 5 days after the initiation respectively. Number of isolation returned to 2 cases, 3, 5 and 10 days after the end of administration respectively and it was same as the number before the initiation of administration.(ABSTRACT TRUNCATED AT 400 WORDS)