An Ode to Droperidol
There are few drugs that make me sing while stopping those in front of me doing the same in the way droperidol does. To be less obtuse, I mean that droperidol is a superb and unsurpassed tool in our pharmaceutical shed. It is a sophisticated instrument, a focussed dart, a brilliant drug for gaining control of the patient with agitated delirium.
Sedating highly aroused and dangerous patients is always fraught. As a procedure it has an extremely narrow therapeutic window. The ledger on the risk side is full. But we in Western Australia have a particular love affair with this agent, as we sport the unenviable crown of methamphetamine capital of the world. Why that might be is an entirely different story. It has, however, afforded us the opportunity to gain some rather extensive experience with rapid, effective sedation.
I am old. I have plodded through generational changes when it comes to sedation in the Emergency Department. When I was a trainee all we had was midazolam and occasionally thiopentone for RSI, and for sedation of agitated patients we only had access to midazolam and haloperidol. A rule of thumb was when you reached 50mg of each of those, without success, it was time to think about alternatives. Having said that, these were the pre-meth days; the drugs were paler, and many people would simply get quiet, sleepy, and a little apneic on heroin and the like. Bring back the heroin, I say.
But now our sedation needs are substantially more complex. Thankfully too, are the drugs. We are grateful here that droperidol did not earn itself the Black Box warning it did in the States. Now there’s an interesting occurrence. Droperidol as a single agent does not, and has never been shown to, increase the QT interval in a clinically relevant way to cause Torsades. A recent study published in The Annals of Emergency Medicine confirms this (1). That whole Black Box episode felt kind of fishy, didn’t it? Was there more to the story than the concern for Torsades? Should we be following the money? I don’t know. This is not the column for such questions. I am a tortured poet wearing the skin of an Emergency Physician, not an investigative journalist. The problem is though, the stench of being besmirched in this way lingers. I have no doubt people are still suspicious of using droperidol, or perhaps are unfamiliar with its use. Maybe unsure of its benefits. Well let me, as Shakespeare would say, count the ways.
As a butyrophenone, or early generation antipsychotic, it has a bespoke profile of reducing psychomotor agitation (a strong calmative factor in those sympathetically aroused), decreasing psychosis (as it says on the label), and is sedating without much respiratory depression. The trifecta of calm. It can be given safely intramuscularly, or intravenously. 10mg as starting dose is consistently safe. We, in my shop, almost always use IV. We have a batallion of security staff to assist in keeping a limb steady and free, allowing us to leap like gazelles on top of the patient and insert an IV. Many (in fact most, worldwide) consistently argue against this approach, saying IM is safer all round, but the 20-30 minute lag time for effect is simply not possible to endure in a department heaving with multiple similar patients on the go at any one time, and the patient in question displaying the strength, manners, and danger of a riled up beast from the African Plains.
Droperidol does well with a seasoning of benzodiazepine. We tend to dribble in midazolam as a chaser, but this is no longer the predominant agent. Data from the DORM study (2) and others repeatedly tell us that the more benzodiazepines are used, the greater the risk of adverse events, primarily decreased respiratory function, desaturation, and requirement for airway intervention.
Ketamine is a relative newcomer on the block for IM sedation of the patient with agitated delirium. It, too, can be spectacularly effective, but its side effect profile is also slightly worse than droperidol, plus the biologic argument for not using an agent that itself causes sympathetic stimulation in the already out-of-control sympathetic tornado of methamphetamine intoxication is compelling (although I concede that data is not bearing this out to date). 4mg/kg IM is certainly effective, and quicker than some of the other IM agents (mean time to effective sedation is somewhere between 10 and 20 minutes).
As always, it is up to each of us to make best decisions about therapeutic interventions based on the best available evidence. We know no single piece of evidence is watertight, and protocols and personal preference and patient populations vary around the world with staggering heterogeneity. This column was simply my little love-song to droperidol, a most elegant agent, one that has saved my skin more times than I could possibly count.
It only seems fitting to finish with Sonnet 27, by the Bard himself.
Weary with toil I haste me to my bed,
The dear repose for limbs with travel tired;
But then begins a journey in my head,
To work my mind, when body’s work’s expired:
For then my thoughts (from far where I abide)
Intend a zealous pilgrimage to thee,
And keep my drooping eyelids open wide,
Looking on darkness which the blind do see: