A Look Back at Intravenous Haloperidol for Delirium

I found one of my old blog posts about using intravenous infusions of haloperidol for delirium in the intensive care unit. The bottom line is it that it probably should not be used, in my opinion. This is sort of a follow up on my Christmas Eve blog post in which I mention talking to ICU personnel about using IV haldol for delirium. I’ve edited out a portion of the old post.

Notes on Pharmacology for the Treatment and Prevention of Delirium: IV Haldol Infusions

“I ran across the Canadian Coalition for Seniors’ Mental Health guidelines for the management of delirium in elder adults. You can access them for free at the at this link, CCSMH – Canadian Coalition for Seniors’ Mental Health. I was a bit surprised to read the following recommendation:

“For those who require multiple bolus doses of antipsychotic medications, continuous intravenous infusion of antipsychotic medication may be useful.“

Note: I read this in 2011. I’ve rechecked the website of CCSMH, which shows the same recommendation when I reviewed it on December 27, 2023.

The recipe for continuous infusion of haloperidol was in a paper by Riker and I thought it was of historical interest[1]. Essentially, if the delirious patient had not responded to 8 consecutive 10mg bolus injections of haloperidol, you asked the intensivists to start a haloperidol drip at 10mg an hour. It usually didn’t work and despite the puzzling tendency for experts to claim that extrapyramidal side effects (EPSE) such as dystonias, parkinsionism, and akathisia occur at a lower rate when haloperidol is infused intravenously, the dissenting opinion from experienced psychiatric consultants including me is—if you do this enough times you’ll see EPSE. I’ve witnessed everything from trismus to opisthotonos, on one occasion all in one patient as I stood there and watched him over minutes while the intravenous (IV) haloperidol was infusing.

The idea that IV haloperidol infusions seems to stem in part from a 1987 paper by Menza[2]. There were only 10 patients total in that study.

My comments: I remember a presentation at an Academy of Consultation-Liaison (ACLP) meeting many years ago reporting that EPS (extrapyramidal side effects such as dystonia) had been reported to occur after IV administration in 67% of normal humans given a single dose, in 16-74% of adults with medical illness including burns, migraine, and Human Immunodeficiency Syndrome, and in 37% of psychiatric inpatients. EPS occured after IV administration of other dopamine blockers including the anti-nausea agent Reglan and there were at least 6 case reports of Neuroleptic Malignant Syndrome (the “ultimate EPS”) following IV administration of haloperidol.

The presenter reporter that no EPS occurred in several cases of reported very high dose IV Haloperidol, e.g., 945mg/ in 24 hours; and 1155mg in one day (from his own case report in 1995). It may have had something to do with delirium itself being a highly anticholinergic state.

There have been improvements in the management of delirium in the ICU since then. The best example I can give would be what Dr. Wesley Ely, MD has been doing for years at Vanderbilt.

1.            Riker, R.R., G.L. Fraser, and P.M. Cox, Continuous infusion of haloperidol controls agitation in critically ill patients. Crit Care Med, 1994. 22(3): p. 433-40.

2.            Menza, M.A., et al., Decreased extrapyramidal symptoms with intravenous haloperidol. J Clin Psychiatry, 1987. 48(7): p. 278-80.