Why does hospice use haloperidol (Haldol) for nausea?

We’ve all heard we should use, but why? Well, the answer is multifactorial, just like the drug. Let’s first start with the idea that as patients decline limiting the number of medications is always a goal, especially when we know swallowing will become more difficult. Picking a medication that we can use for nausea and agitation/delirium just makes practical sense.

Now pharmacology wise if we look way back into the archives, we find that everyone was looking for medications to treat schizophrenia and haloperidol was highly successful, but it was also discovered that patients in those studies didn’t have nausea… Well, another drug, prochlorperazine (Compazine) was trying to enter the space as a schizophrenia drug, but it didn’t really work as well. So, marketing said “ok haloperidol you can have schizophrenia, we’ll go after nausea”. And as you sit here today reading this, you realize that marketing (yes before Google and Social Media ads), played a role into drug selection. But in all seriousness let’s talk chemistry for a minute. The reason prochlorperazine was good for nausea and not as good for schizophrenia is because even though the both have binding affinity for the dopamine receptors, prochlorperazine binds then releases, binds then releases. Haloperidol likes to bind and hang on. That binding and hanging on is what gives haloperidol that bad rap for extrapyramidal side effects especially over long treatment courses, which you have with schizophrenia. Flash back to hospice, most of end-of-life nausea is dopamine mediated at the chemoreceptor trigger zone (CTZ) and guess what… it’s not going away. Their cancer, end stage renal disease, liver, etc. will be here tomorrow. So, unlike transient nausea, we benefit from the binding and holding on at the receptor. We need the medication to stay around to keep nausea at bay. This is often why haloperidol is given in small doses like 0.5mg twice a day and then as needed for breakthrough. If we keep the doses under 2mg, then our likelihood for extrapyramidal side effects, combined with shorter life expectancy, makes haloperidol’s risk equivalent similar to the other antipsychotics like risperidone (Risperdal) and olanzapine (Zyprexa).

So, there you have it. Why does hospice use haloperidol for nausea? It targets the most common cause of nausea at end-of-life, helps us limit medication administration by providing flexibility with dosing, treats multiple symptoms, can be crushed, used rectally, comes in a concentrated liquid, injectable that can be given subcutaneous, and has equivalent efficacy and risk.

Clinical Peal: In general, if you find you’re needing more than 2mg of haloperidol for nausea regularly, pause and go through the causes of nausea. You will often find the nausea to be multifactorial too, like CTZ and anticipatory nausea.

Lastly, we all know that extended care facilities/nursing homes F-Tag antipsychotic use, not just haloperidol, but all of them. We also know there is extra excitement about haloperidol. There is no magic bullet for this hurdle other than education and developing a working relationship with the consulting pharmacist assigned to that facility on the best management for patients at end of life.