Oral bacitracin vs vancomycin therapy for Clostridium difficile-induced diarrhea. A randomized double-blind trial.

The effectiveness of a ten-day course of either oral bacitracin or oral vancomycin hydrochloride for treatment of Clostridium difficile-induced antibiotic-associated diarrhea was compared in a randomized double-blind study. Bacitracin was as effective as vancomycin in resolving diarrhea; most patients responded within five days of therapy with either drug. Three patients receiving bacitracin worsened during therapy; two of these were considered treatment failures. Neither C difficile nor its toxin was detected in stool samples collected on the final day of therapy in 71% of patients (10/14) receiving vancomycin and in 30% (3/10) receiving bacitracin. Five patients receiving bacitracin and three receiving vancomycin had at least one recurrence. Low but nontoxic concentrations of bacitracin were detected in serum samples collected from 11 patients. Oral bacitracin at this dosage level was as effective as vancomycin in resolving the symptoms of C difficile-induced antibiotic-associated diarrhea in most patients but was less effective in eradicating C difficile and its toxin from patients' stools.