Abstract
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 59.5-70.5kg (65.6 kg, on average) were measured by injecting 1,000mg 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.
1. In the fecal flora, the population of Enterobacteriaceae on average was 107 cells/g feces on the day of the initiation and decreased by 2 logarithms to 105 cells/g 3 days after the initiation, 105 cells/g feces 5 days after the initiation with no bacterial isolation in 2 cases, 107 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 109 cells/g feces due to the isolation of one 1010 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.
As to Gram-positive Staphylococcus sp., average population was in the level of 108 cells/g feces on the day of the initiation and it increased by 2 logarithms to 1010 cells/g feces 3 days after the initiation and was in the range of 107-109 cells/g 5 days after the initiation, 3 and 5 days after the end of administration, which was similar to the level at the time of initiation. At the end of the administration, number of isolation case decreased to 5 but this was not considered to indicate a decreasing trend due to 4 isolation cases detected 3 days before the initiation of administration. There was not a significant change in the population of Enterococcus sp. with 107-109 cells/g feces range on any day of the examination. The population of Candida sp. was in the level of 108 cells/g feces both 3 days before the initiation and on the day of the initiation, but it showed a gradually-increasing trend with 105, 107 and 108 cells/g feces 3 and 5 days after the initiation and 3 days after the end of administration, respectively. It was in the level of 106 cells/g feces 5 days after the end of administration and there were 3 isolation cases 10 days after the end of administration and one of them showed a higher population than at the initiation by 3 logarithms.
