The use of tobacco in the Shuar tradition is integral and essential in an ayahuasca ceremony, perhaps I should have mentioned that specifically. It is not really 'drinking' though and it is not enough in quantity to cause an adverse reaction in what I would guess is the absolute majority of all people- just a teaspoon's worth, inhaled through the nose.
There is a Shuar tradition of drinking the equivalent of maybe 12 ounces of tobacco water, to induce visionary dreams. This could be dangerous to a non-tobacco user or newbie due to the high nicotine content, however, the worst I've heard or seen is people vomiting. If a person drinks so much that they die, I would imagine the Shaman in question was acting irresponsibly. The Shaman I work with would advise newcomers to take things slowly and would not give high doses to anyone but the most experienced.
RE: Shamanism, tobacco & ayahuasca: what to expect and how to prepare.