Influence of cimetidine on the disposition of ibuprofen in the rat.

Ibuprofen is a non-steroidal anti-inflammatory agent which is extensively metabolized in both man and the rat. Cimetidine is a well known H2 antagonist which is known to inhibit microsomal enzyme drug metabolism. The influence of cimetidine on the disposition of ibuprofen was studied in Sprague-Dawley rats. Pretreatment with cimetidine was found to increase both the rate and extent of absorption of ibuprofen. Cimetidine treatment also inhibited acidification of gastric fluid. Pretreatment with SKF525A increased ibuprofen half-life but not absorption. Additional studies are necessary to determine the effect of cimetidine on the half-life and absorption of ibuprofen in man.