Concurrent administration of cimetidine and enteric‐coated prednisolone: effect on plasma levels of prednisolone.

Unpredictable Performance of pH-Dependent Coatings Accentuates the Need for Improved Predictive in Vitro Test Systems

“…As for how elevated gastric pH affects the performance of enteric-coated products, the studies of which the authors are aware have so far not found any effect: one study found that the pharmacokinetics of EC prednisolone were not affected by cimetidine coadministration suggesting that the elevated gastric pH would not affect the performance of this EC product. 15 However, the gastric pH was not measured and treatment administration was after light breakfast rather than during the fasted state. Therefore, this study cannot be considered to conclusively eliminate the possibility of elevated gastric pH affecting the performance of enteric-coated dosage forms.…”

The effect of intravenous cimetidine on the absorption of orally administered diazepam and lorazepam.

“…The situation is more complex when one considers its administration to patients who are being treated with enteric coated preparations. Morrison et al (1980) found that although the coating should be soluble at pH 5 to 7, the bioavailabilty of prednisolone from an enteric-coated formulation was not affected by cimetidine under circumstances similar to those in which both drugs would be used by patients. Fisher et al (1980) found reduced absorption of tetracycline with singles dose administration, but Garty & Hurwitz (1980) did not find this with chronic administration.…”