In this 12-week pilot study, 35 adult PSC patients were randomized into one of 4 groups:

1. 1. 125 mg oral vancomycin 4x/day
2. 2. 250 mg oral vancomycin 4x/day
3. 3. 250 mg metronizadole 3x/day
4. 4. 500 mg metronizadole 3x/day

One goal of this study was to investigate the safety and efficacy of these drugs. Another goal was to see if the following endpoints decreased: alkaline phosphatase, serum bilirubin, Mayo Risk Score, and pruritus.

Both vancomycin and metronidazole demonstrated efficacy; however, only patients in the vancomycin groups reached the desired decrease of alkaline phosphatase. The vancomycin group also experienced less adverse effects.