My study on a recently dead tyrannosaurus rex revealed that the poison glands are located at the tip of tyrannosaurus' ears. Do you know what kind of a venom these glands produce?
To the best of my knowledge the Tyrannosaurus Rex was a theropod dinosaur that lived from the Maastrichtian age of the Upper Cretaceous period, 68 to 66 million years ago. 
Although some soft tissue and protein remains have been found there are no reports of any poison glands. 
So I can unfortunately not answer your question.
You are assertive of it, but you may be wrong. A new paper suggests that Sinornithosaurus a venomous dinosaur, based on its grooved teeth and hollows where venom glands could have sat. 

Sinornithosaurus (meaning “Chinese bird-lizard”) is a small feathered dromaeosaurid (or, more commonly, ‘raptor’) and an early distant cousin of the birds. Its teeth are unusually large and Gong says that those in the upper jaw are “so long and fang-like that the animal appears to be saber-toothed”. They’re very similar to the fangs of back-fanged snakes like boomslangs and vine snakes. 
https://www.nationalgeographic.com/science/article/groovy-teeth-but-was-sinornithosaurus-a-venomous-dinosaur
Paleontology, like most sciences, is an ever evolving discipline, so it is possible that I am wrong.

Even the Sinornithosaurus' venomous glands finding by Gong et al in 2009 was disputed in 2010 by a team of scientists led by Federico Gianechini. They noted that grooved teeth are not unique to this genus, the teeth were not abnormally long as Gong and his team claimed, but rather had come out of their sockets, and that they could not independently verify the presence of supposed chambers for venom glands cited by Gong's team, finding only the normal sinuses of the skull. Gong and his team also submitted a reassessment of the 2009 study, casting doubt on their findings.

While it is possible that either or both the Tyrannosaurus Rex or the Sinornithosaurus were venomous animals, current evidence does not support this claim.