Impact of cefotaxime and ceftriaxone on the bowel and vaginal flora after single-dose prophylaxis in vaginal hysterectomy.

The aim of this randomised controlled study was to investigate the effect of a preoperative, single dose, intravenous injection of ceftriaxone 2g and cefotaxime 2g in 2 groups of 30 patients who underwent vaginal hysterectomy. The parameters were: efficacy and tolerance; impact on the aerobic bowel and vaginal flora; and serum concentrations. There were no significant differences in efficacy, haematology or clinical chemistry parameters. In the ceftriaxone group 2 patients had exanthemas, 2 had diarrhoea. In the cefotaxime group no such side effects occurred. Serum concentrations were 9.75 and 0.07 mg/L for ceftriaxone and cefotaxime, respectively, after 24 and 12 hours, respectively. Ceftriaxone had a pronounced and continuous effect on the bowel flora: Streptococcus faecium and Candida spp. increased, reaching counts of 10(8) and 10(7) organisms/g faeces, respectively, at day 10. Under cefotaxime no dramatic alteration was determined and growth of Candida spp. was not influenced. Growth of Escherichia coli and other bacteria of the vaginal flora was not influenced by either drug. Overgrowth of Candida spp. under ceftriaxone was significant (p less than 0.05) compared with that under cefotaxime. The results of this study indicate that the high biliary excretion of ceftriaxone (45%) and its long acting properties are responsible for the high selection pressure and overgrowth of Candida. Cefotaxime, a drug with low biliary excretion (5%) and shorter action, had only a negligible effect on the microflora with quick normalisation. The observed overgrowth of Candida spp., even after a single injection of ceftriaxone, could cause problems when this drug is being used for surgical prophylaxis or treatment. This applies especially to immunocompromised patients.