brand name zantac and its generic form from shelves. why, what do consumers need to know here? >> this is interesting, this is what we've heard before regarding an imbupurity called ndma or the zantac. it's an impurity, that in large amounts has been associated with cancer in animals. in that low amounts, in humans, we don't know. but these drug store chains including cvs are being pretty cautious here. i will say that the fda is being a little less concerned. they're basically saying, look, these levels are such low amounts, they're the same amounts found in many common foods. they say, look, you can consider switching from zantac to another over-the-counter medication if you're concerned.