Hallucinogenic drugs are unique in that they produce the desired hallucinogenic effects at what are considered non-toxic doses. The
hallucinogenic drugs can be categorised into 4 basic groups:
indole alkaloid derivatives,
piperidine derivatives,
phenylethylamines and the cannabinols. The drugs reviewed include
lysergic acid diethylamide (
LSD),
phencyclidine (PCP),
cocaine,
amphetamines,
opiates, marijuana,
psilocybin,
mescaline, and '
designer drugs.' Particularly noteworthy is that each
hallucinogen produces characteristic behavioural effects which are related to its serotonergic, dopaminergic or
adrenergic activity.
Cocaine produces simple
hallucinations, PCP can produce complex
hallucinations analogous to a paranoid
psychosis, while
LSD produces a combination of
hallucinations, pseudohallucinations and
illusions. Dose relationships with changes in the quality of the hallucinatory experience have been described with
amphetamines and, to some extent,
LSD. Flashbacks have been described with
LSD and alcohol. Management of the intoxicated patient is dependent on the specific behavioural manifestation elicited by the
drug. The principles involve differentiating the patient's symptoms from organic (medical or toxicological) and psychiatric aetiologies and identifying the symptom complex associated with the particular
drug. Panic reactions may require treatment with a
benzodiazepine or
haloperidol. Patients with
LSD psychosis may require an
antipsychotic. Patients exhibiting prolonged
drug-induced
psychosis may require a variety of treatments including ECT,
lithium and l-5-hydroxytryptophan.