Absence of food effects on the pharmacokinetics of terfenadine

Administration of terfenadine (Seldane) immediately after a high fat breakfast slightly affects the rate but not the extent of absorption relative to fasting administration. Mean peak levels of the active metabolite were increased by 13 per cent but delayed by 0.9 h while AUC was virtually the same as when terfenadine was administered while fasting. Changes in rate of absorption may be due to delayed gastric emptying and more rapid terfenadine solubilization. In any case, these rate differences are unlikely to be clinically important in the absence of differences in extent of absorption.