Friday, October 23, 2020

Chlorpromazine in Delirium FTW!

by Drew Rosielle (@drosielle)

David Hui, Eduardo Bruera, and colleagues have published another important delirium trial out of MD Anderson which I thought was worth blogging about in detail.

In some ways it's related to the same group's RCT a few years ago of lorazepam added to haloperidol for agitation in hospitalized advanced cancer patients with delirium (showing the lorazepam quite effectively reduced agitation via presumably a sedating effect). As I pointed out in the Palllimed post about that trial, while they labeled their patient group as 'agitated delirium in advanced cancer', in essence it was really a sedation for terminal delirium trial as most patients only lived a few days, but a casual reader of the study might not realize that and think they were finding that lorazepam is a disease-modifying therapy for delirium. Which it is not, discrete exception aside (alcohol withdrawal?).

This is an important distinction, as I think there's been a sort of confusion over the years in our discussions about delirium and even research about it between disease-modifying therapy for delirium and essentially palliative-focused therapies to reduce distressing aspects of delirium (primarily agitation). Eg, a drug or drug combo or other intervention that reverses delirium / shortens delirium / returns normal cognition vs a therapy that reduces agitation (because while you could reduce agitation by 'fixing' the delirium you could also do it by sedating the patient). When and whom to just sedate is often complicated, but frankly less so in our patients who have 'terminal delirium' or 'agitation,' insofar as this implies the patient is imminently dying, it is not expected we can reverse the underlying cause of the delirium, and (most often) the goal is to prevent and mitigate suffering during the patient's final days, which in reality ends up meaning sedating the patient (not in a deep, continuous, so-called 'palliative sedation' way, but enough to quiet the distressing motor restlessness etc).

This is a long-winded way of expressing my appreciation for the investigators who, for this study, describe their goal as reducing terminal agitation in advanced cancer patients with delirium, and not treating delirium per se, which is much appreciated.

The trial: this is a single-center, double-blind, parallel-group RCT trial of hospitalized cancer patients at the MD Anderson palliative unit. Basic inclusion criteria were patients had to have a RASS score of 1 or more during the prior 24 h despite being on their group's standard, first-line delirium/agitation therapy which is scheduled + rescue haloperidol (which per their protocol could have been anywhere from 1-8 mg a day, but it's a little confusing and they also note that all the enrollees were put on 2 mg haloperidol q6h scheduled + 2 mg q1h prn before going onto the study drugs protocol). Subjects were randomized in a 1:1:1 fashion to haloperidol dose escalation, switching haloperidol to chlorpromazine, or additing chlorpromazine to haloperidol.

Interestingly, they didn't however clearly define the 'terminal' part of their goal of studying terminal agitation. For what it's worth, this is a study within a single institution's palliative unit, and they basically say that any patient getting to their unit in such a state is very likely to be 'terminal' and they left it at that.

They had a complicated double-dummy design using pre-made syringes of study-drugs/placebo, but essentially patients received one of:

- 2 mg haloperidol q4h scheduled + q1h prn
- 25 mg chlorpromazine q4h scheduled + q1h prn
- 1 mg haloperidol + 12.5 mg chlorpromazine q4h scheduled +q1h prn

If this was inadequate (RASS 2 or higher), doses were essentially doubled in a stepwise fashion. This Table from the Supplement outlines the protocol, it's a bit complicated.

Their primary outcome was the change in RASS at 24 hours. The secondary outcome was the proportion of patients with a RASS score of -2 to 0 at 24 h (basically, that was their goal, to keep patients between -2 which is 'lightly sedated,' and 0 on the RASS).

They randomized about 45 patients between the arms, mean age 63 years, 83% white, and all had a KPS of 30% or less.

There was no difference between groups regarding RASS reduction at 24h, or proportion of patients with a goal RASS at 24h. Most subjects' RASS scores went down about 3 levels (eg from 1 to -2), without differences between treatment arm at 24h.

Nearly all of the other secondary outcomes were the same between groups.

But, a couple of the secondary outcomes that did show differences did seem to favor rotation to chlorpromazine: fewer patients in the rotation to chlorpromazine needed rescue medication in the first 4 or 8 h after blinded drug/s were administered (big differences here, eg 19% in chlorpromazine vs 73% in the haloperidol escalation group at 4 h), and fewer in that group also needed a dose escalation. Ie, although the study wasn't really trying to determine this, their data are suggestive that in the chlorpromazine arm (25 mg q4h scheduled), patients "more rapidly" achieved the desired RASS state than the other arms. They got more comfortable appearing (more sedate) faster, and stayed there, compared to the other arms. I believe these were post hoc analyses, not prespecified secondary findings, so take them with a grain of salt, however the differences were quite marked, and I'm basically persuaded here. Chlorpromazine FTW!

Median survival was 48-72 h in all groups. No differences in side effects/harms between groups were evident.

Bottom line here: escalating haloperidol, rotating to chlorpromazine, or doing a little of both are equally helpful in getting terminally agitated patients more comfortable appearing at 24 h, but switching to chlorpromazine is probably the fastest method.

So, pretty good study. To me, it's an argument that I should be rapidly switching to chlorpromazine when I think death is imminent (days) and a few doses of haloperidol have not achieved much. There's a confusion of options out there, more haldol, chlorpromazine, other sedating neuroleptics (eg quetiapine which I kinda hate but is used all the bleeding time it seems [not by my team], and while this study obviously didn't look into all the options I'm in favor of really making chlorpromazine the drug of choice (when sedation is acceptable, the goal).

For more Pallimed posts about delirium.
For more Pallimed posts by Dr. Rosielle click here.

Drew Rosielle, MD is a palliative care physician at the University of Minnesota Health in Minnesota. He founded Pallimed in 2005. You can occasionally find him on Twitter at @drosielle.

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