Abstract
The pharmacokinetics of metronidazole were studied after oral and intravenous administration to seven patients with Crohn's disease and five patients with ulcerative colitis. The oral/intravenous availability ratio was 0.97 +/- 0.2 in the Crohn's patients and 0.90 +/- 0.1 in the colitics (mean +/- s.e. mean). Plasma clearance was 3.24 +/- 0.2 l h-1 and 4.1 +/- 0.5 l h-1, respectively. These differences were not statistically significant. Ten of the patients on long term sulphasalazine were studied to observe the effect of 2 weeks metronidazole therapy on plasma sulphapyridine concentration. The sulphapyridine concentration changed from 22.1 +/- 2.0 micrograms ml-1 to 15.95 +/- 4.5 micrograms ml-1 in the Crohn's patients and 26.0 +/- 6.0 micrograms ml-1 to 36.4 +/- 8.5 micrograms ml-1 in the colitis group, pre- and post-metronidazole. These differences were not statistically significant. These results suggest that metronidazole does not interfere with diazo-link splitting of sulphasalazine and that patients with Crohn's disease handle metronidazole in a similar manner to patients with colitis.