Actually thats the same with lots of antibiotics, whether the pharmacy puts the label on the bottle or not. You aren't supposed to take calcium or antiacids w/in 1 or 2 hours of fluoroquinolones, cipro, floxin, etc... I think I heard the same thing about not taking iron supplements w/in 1 or 2 hours....and for that matter, not taking many of the oral antibiotics we take with milk. My doctor said it doesn't totally negate its effectiveness, it just blocks some of the absorption, or binds some of the med, but its still somewhat effective, just not the best thing to do.