There are no randomized, controlled clinical trials comparing benzodiazepines, neuroleptics, and placebos in cancer patients. A randomized, controlled clinical trial was completed with AIDS patients. This study found haloperidol and chlorpromazine equivalent to one another and each superior to lorazepam in both efficacy and safety. The intravenous route is preferable in agitated or paranoid patients as it facilitates rapid onset of medication effect. If intravenous access is not practicable, intramuscular or subcutaneous administration is a reasonable option, with oral administration started when possible.
Parenteral doses are roughly twice as potent as oral doses.
Other neuroleptic medications may be useful in the management of delirium, especially if sedation is needed in an agitated person. Chlorpromazine at doses similar to thioridazine is available in oral and intravenous formulations. To date, olanzapine has not been studied in delirium or in organic anxiety syndrome. Olanzapine has a favorable side-effect profile, and is reported to have a lower incidence of extrapyramidal side effects, including akathisia as well as orthostatic hypotension and significant EKG changes, compared with other neuroleptics. A known side effect of olanzapine is significant weight gain.