[Ranitidine ameliorates acemetacin and indomethacin-induced changes of the gastroduodenal mucosa, without modifying the pharmacokinetic behavior of both antirheumatic drugs].

12 healthy volunteers participated in this double-blind, randomized, cross-over study. All subjects were given indomethacin (50 mg tid) or acemetacin (60 mg tid) for 6 days in the presence and absence of ranitidine 300 mg at night. At day 6 120 minutes after the last morning dose an endoscopy was performed and the appearance of the gastric and duodenal mucosa was noted. In the indomethacin experiments mean lesion score averaged 2.2 +/- 0.2 (+/- SEM) when placebo was coadministered. In the corresponding acemetacin-series the lesions score was 1.6 +/- 0.1 (+/- SEM). A reduction in mucosal damage occurred in both NSAID-groups when ranitidine 300 mg at night was given concurrently: The mucosal lesions score was reduced to 1.7 +/- 0.2 and to 1.0 +/- 0.1 (+/- SEM), respectively. This protection afforded by ranitidine was significant when compared with placebo (p less than 0.05). In 8 subjects plasma concentrations of acemetacin and indomethacin were determined on day 1 and day 5. The AUC-values of indomethacin and acemetacin in the presence and absence of ranitidine were almost identical when analysed by the paired T-test. The mean plasma concentrations of both antirheumatic agents did not show any difference when coadministered with placebo or ranitidine. Our data suggest that 300 mg ranitidine at night improves the gastroduodenal tolerability of both indomethacin and acemetacin without affecting main pharmacokinetic parameters of both antirheumatics.