Type of chemical restraints used depends on several factors:
- Is the patient intoxicated on ethanol?
- Is the patient withdrawing from ethanol?
- Does the patient have a primary psychiatric condition?
- Has the patient recently received a benzodiazepine, or is their blood pressure on the lower side?
- Does the patient have a previous history of dystonic crisis or EPS symptoms?
- Is the patient so agitated that they cannot take anything by mouth?
First generation anti-psychotic / benzodiazepine
A common combination used in psychiatric emergency or PICU settings is the 5/2 or the B52 which is used PRN as a chemical restraint (which means that it has to be renewed every 24 hours, unlike the other medications on this page).
- 5/2 refers mixing 5 mg of haloperidol and 2 mg of lorazepam in a syringe and giving the combination to a patient as a single IM injection
- B52 refers to adding 50 mg of Benadryl to the above combination
Haldol and lorazepam can be used on a scheduled PRN basis as seen below for agitation but not necessarily for chemical restraints (if scheduled and if indicated for general agitation, it would then not need to be renewed every 24 hours).
The problem with using haloperidol is that as a first generation anti-psychotic and has a higher risk of EPS symptoms and acute dystonic reactions.
haloperidol 2-5 mg PO/IM q4-6h PRN for severe agitation (maximum 20 mg in 24 hours)
lorazepam 1-2 mg PO/SL/IM q1h PRN for agitation (maximum 8 mg in 24 hours)
-Niagara Health System
If the patient is acutely intoxicated on ethanol do not provide benzodiazepines as this increases the risk of respiratory depression.
If the patient is withdrawing from alcohol or drug intoxication, a benzodiazepine is the appropriate choice.
If a patient has lewy body dementia, do not give haldol as it increases morbidity and mortality!
Loxapine is another first generation anti-psychotic that is commonly used on its own (without adding a benzodiazepine)
loxapine 25-50 mg PO/IM q4h PRN for agitation/anxiety (maximum 250 mg in 24 hours)
-Niagara Health System
Second generation anti-psychotic
Second generation anti-psychotics (SGA) can also be used for chemical sedation.
Risperidone is a second generation anti-psychotic that is available in Canada in pill, ODT and liquid forms but unfortunately is not available in short acting IM form, so the patient must be willing to take it by mouth.
Risperidone, is available in long acting IM form (LAI), but this is used in the context of maintenance therapy for patients who have a history of poor compliance and is often enforced using a community treatment order (CTO). The other SGAs used as LAIs include paliperidone (which is the primary metabolite of risperidone) and aripiprazole.
risperidone 1 – 2 mg PO/SL q2h PRN for severe agitation (maximum 6 mg in 24 hours)
-UTD
Olanzapine on the other hand is available in oral, SBT and acute IM formulation, and is a better option to have as a prn for a patient who is severely agitated and not capable of taking medications IM. Olanzapine is given at a dose of between 5 to 10 mg. Before administering olanzapine however, it is important to determine what the patient’s baseline BP is, as it has a tendency to decrease blood pressure. It should not be given within 1 hour of administering a benzodiazepine.
olanzapine 10 – 20 mg PO/IM q4h PRN for severe agitation (maximum 30 mg in 24 hours)
OR
olanzapine 10 – 20 mg ODT q4h PRN for severe agitation
OR
olanzapine 5 – 7.5 mg PO/IM/SL q4h PRN for mild agitation/hypotension
-Niagara Health System, UTD
Haldol vs olanzapine: His a FGA which has a higher risk of EPS and dystonic crisis, but lower risk of hypotension. Olanzapine is a SGA which has a higher risk of hypotension but a lower risk of EPS and dystonic crisis.
Managing dystonic reactions
On my psychiatry rotation I remember one my patients telling me he was “allergic to haloperidol”. When I asked him what his reaction was he described the following:
- Difficulty with jaw movement
- Spasms of the neck (torticollis)
- Swollen tongue (laryngospasm)
- Upward movement of eyes (oculogyric crisis)
- Vomiting
- Torticollis
In these cases anti-cholinergic medications such as benztropine (Cogentin) or disphenhydramine (Benadryl) are used to manage the reaction
benztropine 2 mg IM immediately
then
following doses of anti-psychotic can be accompanied by prophylactic benztropine