Influence of milk on the bioavailability of doxycycline--new aspects.

This study was conducted to examine the pharmacokinetics of doxycycline in nine healthy volunteers who had fasted overnight. Single-dose cross-over design was used. Each subject received orally 0.2 g doxycycline. The subjects swallowed the antibiotic capsules with 300 ml of water or 300 ml of fresh milk. Simultaneous ingestion of milk diminished the peak plasma concentration by 24% and the absorption by 9-53% (mean 30%). It is concluded that, like the other tetracyclines, doxycycline should not be administered together with milk.