Some have said that nicotine is addictive so baby could become addicted. But there are also a lot of other medications that are addictive that bf'ing mothers take & are considered safe while bf - Vicodin, for example. There are also other medications that there aren't a lot of studies done on their transfer in human milk - but they are deemed safe for nursing mothers to take by the "experts" because of what we know about the properties of that medication. Even Lithium *may* be okay as long as baby is monitored (not something I would feel comfortable taking & bf'ing, personally, but for some, the risk of not bf'ing may be greater).
So - should bf'ing mothers not be able to take ANY medications because it might pass through her milk? What about alcohol? Caffiene? Should bf'ers have to adhere to a strict diet & not take any medications that may or may not be in bm or effect the baby? Even if recent research shows that it is (or may be) okay?