It's a big stretch to compare nicotine with caffeine.....
Actually, from a physiological standpoint both nicotine and caffeine are more similar than not with regards to the effects on the cardiovascular system. That is WHY people who have cardiac and/or circulation are told to get off and stay off of caffeine (coffee, pop, tea). Vasoconstriction, blood pressure rises, those kind of effects.
Water is a poison. If you drink too much it will kill you.
I realise this is an old post but I just had to put this out there....
And so it goes...