Involuntary Chemical Sedation–The Right Medications

Let’s start by setting the stage:  Our patient is a 35 year-old man who is angry that he has been arrested in a domestic dispute case.  He cooperated with the booking process, but then, several hours later, began to repeatedly ram his head full force into the wall.  There is blood on his face and on the wall.  The word “uncooperative” does not do him justice.  He is agitated and belligerent and wants to fight.  He is screaming offensive obscenities. 

Of course, he cannot be allowed to continue to hurt himself.  The deputies take him down and strap him to a restraint chair.  A spit mask is required.  Nobody really expected him to calm down after he is placed in the restraint chair and they are not disappointed.  30 minutes later, he is still screaming.Restraint

This patient certainly meets the criteria for chemical sedation.  He is an acute danger to himself.  He is an acute danger to others.  He has refused voluntary sedation.  He is not hypoxic or hypoglycemic (but if there is a suspicion of this, it is easy enough to get a pulse oximetry reading or a finger stick blood sugar).

What medications should be used to sedate this patient? 

Remember that our goal is to sedate the patient so that he can be released from physical restraints.  We would like him to be sedated and drowsy and even go to sleep, but to be easily arousable.  We do not want respiratory depression or other serious side effects.

The two main drug classes that have been traditionally used for this type of chemical sedation are the benzodiazepines and the antipsychotics.  I was taught in my Emergency Medicine residency that the benzos were “minor sedatives” and the antipsychotics were “major sedatives.”  However, there have been several studies comparing the two when sedating agitated patients, including this 2010 Cochrane Review, and, in fact, both work well.  They may work even better when given together.  Each has advantages and disadvantages that should be considered.

 Antipsychotics for Sedation–Haloperidol

The best overall antipsychotic for rapid sedation of agitated patients in a correctional setting, in my opinion, is good, old haloperidol.  Haldol has been safely used for this indication (probably) millions of times world-wide.  It is “tried and true.”  It is Vitamin H.  The Velvet Hammer.

The main advantage of haloperidol is that it is so safe.  It does not cause respiratory depression and so can be given to intoxicated patients.  It has no dose limit for safety reasons.  This means that it can safely be given to patients who are already taking antipsychotics.  The dose is the same whether po or IM, so if a patient changes his mind and accepts oral meds, it is easy to change course.  It can be given IV as well as IM (though we would seldom give haloperidol IV in a correctional facility as is done routinely in ERs).

 “Haloperidol has been evaluated in a large number of clinical trials alone and in combination with benzodiazepines.  These studies demonstrate that intramuscular haloperidol is both safe and effective in the treatment of agitation caused by virtually any etiology” Roberts: Clinical Procedures in Emergency Medicine, 5th ed.

Any other antipsychotic that can be given IM can also be used for rapid sedation.  Possibilities include Inapsine (droperidol), Geodon (ziprasidone), and Zyprexa (olanzapine).  There is nothing wrong with any of these agents, and if you already use them and are comfortable with them, that is great.  They offer no advantages to Haldol, however.  None are more effective and none are safer.

The major potential adverse effects of acute one-time dose Haldol administration are exceedingly rare.  One of these is Q-T prolongation that can, potentially, cause dysrythmias.  Another is Neuroleptic Malignant Syndrome. Both of these are very rare, however, and the risk is far less than the risk of prolonged physical restraint.  Haldol has also been reported to lower the seizure threshold, but this is controversial.

The one reasonably common adverse effect of acute IM Haldol administration is a  dystonic reaction.  Dystonic reactions involve involuntary muscle contractions  usually in the neck, shoulders or face, but also elsewhere.  It can also manifest as akesthesia, which can be thought of as a case of restless legs from hell.  We are not talking here about Tardive Dyskinesia. Tardive Dyskinesia is also involuntary muscle contractions but these occur after years of neuroleptic medication use and are irreversible.  Acute dystonic reactions are easily reversible, using an antihistamine, like Benadryl.  Unlike tardive dyskinesia, dystonic reactions are a nuisance, trivial and easily treated.

Because of the possibility of a dystonic reaction to IM Haldol, some practitioners give Benadryl 50mg IM at the same time as the Haldol.  I do not do this for the following reasons:

  1. The dystonic reactions from Haldol tend to occur the day following the IM injection.  Benadryl is so short acting that it is gone by then.  Theoretically, then, it may not be effective in reducing dystonic reactions.  This has never been studied, as far as I know.
  2. Only 1 in 6 or 7 patients who receive a single Haldol injection will develop dystonia.  If you give Benadryl to everyone, you are treating the majority of patients needlessly.  Benadryl has its own set of ill effects and side effects.
  3. If a patient does develop dystonia the next day, 50mg of Benadryl given orally will solve the problem quickly at that time.  That is when I prefer to treat these nuisance reactions.

The standard adult dose of Haldol for rapid sedation is 5-20 mg IM.DSC01310

Benzodiazepines for Sedation–Lorazepam

Any benzodiazepine that can be given IM can be used for chemical sedation.  I like to use Ativan (lorazepam), myself.  Valium can be used but is not as good because it is not well absorbed from an IM injection.  Versed (midazolam) is an acceptable alternative to Ativan.

The main disadvantage of Ativan as a chemical sedative is that it can cause respiratory depression, especially when combined with other sedating drugs.  For example, it should be used cautiously in the obnoxious drunk.  Haldol alone is a better choice for him.  It also reportedly can cause hypotension, though I have never seen this.

On the other hand, lorazepam is an excellent choice for stimulant overdoses.  It almost can be thought of as an “antidote” to stimulant “poisoning.”  So the patient who is agitated while “tweaking” on meth would do well receiving lorazepam.

The standard dose of lorazepam for chemical sedation is 1-4mg IM.

Combination Therapy

One cool thing about Haldol and Ativan is that they play well together.  The medical term for this is that they are synergistic—they increase each other’s effectiveness.  In practical terms, this means that if they are combined, you can use a smaller total dose of each agent.  Instead of needing 4mg of lorazepam IM to sedate a patient, if you combine it with Haldol, you only may need 1 or 2 mg  and vice versa. The two drugs are so compatible that you can mix them together in the same syringe.

The standard dose of the combination used for chemical sedation of the agitated patient is “ten and two” meaning 10mg of Haldol and 2mg of Ativan.  You can reduce this to “five and one” or increase it depending on the circumstances.  You can also vary the ratio or use just Haldol or just lorazepam depending on a particular case.  For example, what would you use in these cases?

  1.  The Standard Jerk.  This is the patient who is agitated and belligerent not because of drugs or alcohol,  but because of frustration, manipulation or whatever.  Chemical Sedation:  “Ten and Two” (Haldol 10mg and lorazepam 2mg IM).
  2. The “Mean Drunk.” This patient is still intoxicated, so you might not want to use lorazepam since it potentially could cause respiratory depression in combination with the alcohol.  Chemical Sedation:  Haldol 10mg IM.  It will not cause respiratory sedation and can be used safely in an intoxicated patient.
  3. The Acutely Psychotic or Manic Patient.  Chemical Sedation?  “Ten and two.”  Sometimes these patients need a second dose in an hour.  Should we be worried that the patient is already taking antipsychotics (let’s say Abilify, for example)?  The answer is no.  You can still safely give Haldol.
  4. Methamphetamine Intoxication.  Lorazepam is the “antidote” for the patient who is tweaking on meth or cocaine.  Chemical Sedation?  Lorezepam 4mg IM.  You can add 5mg of Haldol, as well if you want.
  5. “Undifferentiated.”  If you just do not know why the patient is agitated and belligerent, remember that “intramuscular haloperidol is both safe and effective in the treatment of agitation caused by virtually any etiologyRoberts: Clinical Procedures in Emergency Medicine, 5th ed.  If you are reasonably sure the patient is not drunk, add the lorazepam, as well.

 Next installment in the series:  Chemical Sedation:  Right Documentation and Right Follow –Up.

What medications do you use for Involuntary Chemical Sedation at your facility?  Please comment!