There are a very large number of toxins that can lead to hallucinations and/or delirium.
A psychotomimetic reaction, with apparent visual or auditory hallucinations, delirium and heightened or only slightly decreased level of consciousness, is most commonly due to:
In addition, a large number of drugs that impair consciousness may lead to delirium usually without significant hallucinosis. These drugs are discussed under drugs leading to coma.