Effect of cefoperazone on faecal flora.

The effect of cefoperazone on the intestinal flora was investigated in 29 patients receiving the drug for 7 to 14 days. Faecal specimens were cultured quantitatively for aerobic and anaerobic micro-organisms before, during and after therapy. The cefoperazone treatment was associated with major changes in the faecal flora. There was marked suppression of enterobacteria, staphylococci, streptococci, anaerobic cocci, bacteroides, fusobacteria, bifidobacteria, eubacteria and lactobacilli. The number of enterococci increased in most patients and the number of clostridia remained constant. Eight patients had cultures positive for Clostridium difficile during or after treatment. The marked changes in the intestinal flora can have important clinical consequences.