Dairy products reduce the bioavailability of ciprofloxacin (AUC reduced by about 30%) and
norfloxacin (peak
plasma levels reduced by about 50%), and to a minor extent,
gatifloxacin (AUC reduced by 15%).
The effect of these changes on the
control of
infection is uncertain but it would seem prudent to advise patients not to take these dairy products within one to 2 hours of either ciprofloxacin or
norfloxacin. The slight reduction in
gatifloxacin levels is probably not clinically relevant. Enoxacin,
lomefloxacin,
ofloxacin and probably fleroxacin do not appear to interact significantly. They therefore may
provide a useful alternative to the interacting
quinolones. Consider also enteral feeds.