IDK about other vampires, but I would say that Ricean vampires are not in fact poisoned by dead blood, they can drink it, it’s just very distasteful to them. I’m not going to use all the equivocating language like “may,” and “might,” this is all my very strong opinion on this topic so as always #your headcanon may vary, don’t take it personally if we disagree.

{{Oh Louis, bb, we know, it gets cold so quickly…}}

The huge difference between dead mortal (human or animal) blood and vampire blood is that the *~vampiric parasite~* in vampire blood keeps them alive/undead. Ricean vampires aren’t 100% dead (though they may poetically feel that way), they are metamorphosed into a supernatural accident. 

Lestat does say in the movie (and this is probably where the confusion about the supposed lethalness of dead blood comes from, too), “You let me drink *dead* blood?!” and it might seem like he means that the deadness of it was the lethally poisonous aspect of it, when in actuality he knows he’s been drugged, it was the absinthe & laudanum combo that’s incapacitated him. Still, those drugs are not poisonous to a vampire; he asks to be put in his coffin like a mortal might want to be put to bed, to sleep it off. Claudia did it to bring his defenses down so she had a chance at killing him. He couldn’t fend her off as well in that drugged state.

In TVL, Lestat goes to Armand in Paris for help after Claudia and Louis try to assassinate him a second time, and Armand throws him in a locked cell with a dead mortal for dinner:

“Sometime in the dark, I discovered a mortal victim there. But the victim was dead. Cold blood, nauseating blood. The worst kind of feeding, lying on that clammy corpse, sucking up what was left.”

^So clearly dead blood is not bad in the sense of being poisonous, just icky 😛 It must still have some minimal nutritional value since he feeds on it anyway.

Hit the jump for a little more, cut for length.

Lethal/poisonous blood is not about the blood itself, but is about the moment of death of the victim: What movie!Lestat warns Claudia about in Vampiring 101: (and he warns Louis in the book!IWTV) is that she must stop drinking before the victim’s heart stops, at least in the beginning, or else the victim could take her down with them in death. That’s more about the soul separating from its body at the moment of death. Older/stronger vampires can keep drinking and slurp the impact of the death down, too. Lestat describes doing it in TVL against his maker’s advice bc of course he goes against his maker’s advice:  

“…and when the blood came it was
pure voluptuousness. In fact, it was so exquisite that I forgot
completely about drawing away before the heart stopped. We were on
our knees in the snow together, and it was a wallop, the life going into
me with the blood. I couldn’t move for a long moment. Hmmm,
broke the rules already, I thought. Am I supposed to die now?
Doesn’t look like that is going to happen. Just this rolling delirium.”

Also worth noting is that when mortals are turned in canon, they describe vampire blood as being extremely delicious, satisfying in more than a physical way: “And it was not merely the dry hissing coil of the thirst that was quenched and dissolved, it was all my craving, all the want and misery and hunger that I had ever known.” – Lestat (TVL). Strong words! AR has equated the Dark Gift to childbirth and I think the act of the fledgling feeding on their maker is very much like an infant at its mother’s breast. That kind of nourishment is physical AND emotional.

Personally, I’ve tasted dead blood very recently, I just had chocolate blood pudding a few days ago at the Feeding Hannibal dinner (with @mferret9​, @sarah-thetrappedcat, and @thatironstring​!) and it was yummy but it does not produce that kind of satisfaction. At least not for me!