3 Clinical psychopharmacology3.4 Therapeutics
3.4.7 Pharmacological management of psychiatric emergencies
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Written by Resident Doctor Committee · Published
Before any drug is given
The aim is calm wakefulness that allows assessment and care, not sleep.
Check airway, breathing, circulation, consciousness, vital signs and capillary glucose, and look for physical causes such as hypoxia, hypoglycaemia, infection, seizures and delirium.
Count every dose already given, including by ambulance and emergency staff, and ask about intoxication, allergies and pregnancy.
Use de-escalation first and offer oral medication before injection.
Choice of drug
Rapid tranquillisation usually means intramuscular (IM) medication when oral treatment is unsuitable. The National Institute for Health and Care Excellence (NICE) adult options are IM lorazepam alone or IM haloperidol with IM promethazine.
Situation | Choice |
|---|---|
Active psychosis, tablets accepted | Oral newer antipsychotic |
Respiratory disease | Avoid inhaled loxapine |
No baseline electrocardiogram (ECG), cardiac disease or QT prolongation | Avoid haloperidol; NICE favours lorazepam |
Stimulant toxicity | Benzodiazepine, with temperature and cardiovascular monitoring |
Catatonia | Lorazepam; antipsychotics can worsen it |
Alcohol or opioid intoxication | Benzodiazepines add to respiratory depression |
Parkinson's disease, dementia with Lewy bodies | Haloperidol is contraindicated |
Akathisia | Review the causative drug; more antipsychotic may worsen it |
In psychotic agitation an antipsychotic calms and treats the cause, whereas a benzodiazepine or antihistamine only sedates.
In organic disinhibition, benzodiazepines are avoided because enhancing gamma-aminobutyric acid type A (GABA-A) receptors releases behaviour further when frontal control is already damaged.
Trazodone, selective serotonin reuptake inhibitors, valproate and beta-blockers have some evidence of reducing disinhibition or aggression.
Staff give a single dose and review it before repeating, because doses stacked before earlier ones take effect cause delayed respiratory depression.
Acute mania
UK licence | Drugs |
|---|---|
Acute mania | Aripiprazole, quetiapine, olanzapine, risperidone, haloperidol |
Relapse prevention | Carbamazepine, lamotrigine |
Schizophrenia only | Clozapine, lurasidone |
Benzodiazepines are used briefly for severe agitation or insomnia while a continuing antipsychotic or mood stabiliser plan is set up.
Complications of rapid tranquillisation
Finding | Action |
|---|---|
Respiratory rate under 10 per minute or oxygen saturation under 90% | Give oxygen, raise the legs and keep the patient off their face; then intravenous (IV) flumazenil if a benzodiazepine is the cause |
Postural fall in blood pressure over 30 mmHg, or diastolic under 50 mmHg | Lie the patient flat with the head of the bed lowered |
Pulse under 50 per minute or irregular | Sinister sign, as haloperidol prolongs QT and causes arrhythmia; refer immediately to specialist medical care |
Rising temperature | Possible early neuroleptic malignant syndrome (NMS); give no more antipsychotic and check creatine kinase (CK) urgently |
Acute dystonia | Parenteral anticholinergic; airway support if the larynx is involved |
Obstructed or noisy breathing | Open and clear the airway and call skilled help |
NICE observations after rapid tranquillisation are at least hourly, and every 15 minutes after high doses or when the person is asleep, sedated, or has used alcohol or drugs.
Flumazenil
Flumazenil acts at the benzodiazepine site of the GABA-A receptor.
Its half-life is about an hour, shorter than the benzodiazepines it reverses, so sedation can return and repeat doses may be needed.
It has no UK licence for benzodiazepine overdose.
It can provoke seizures and withdrawal, particularly in dependence or after proconvulsant co-ingestants.
Drug-induced syndromes and catatonia
Syndrome | Recognition | Treatment |
|---|---|---|
NMS | Rigidity, fever, autonomic instability, very high CK after antipsychotic exposure | Stop the drug, supportive care and cooling; bromocriptine, a dopamine agonist, reverses D2 blockade |
Catatonia in depression | Mutism, posturing, staring; normal CK; no antipsychotic exposure | Lorazepam challenge first line, which usually works in affective catatonia |
Serotonin syndrome | Rapid onset of clonus, hyperreflexia, dilated pupils, diarrhoea | Stop the drugs and give a benzodiazepine; cyproheptadine if it persists |
Antipsychotic-induced syndrome of inappropriate antidiuretic hormone secretion (SIADH) | Low sodium, concentrated urine, normal volume status | If mild and asymptomatic, fluid restriction and regular sodium checks |
Anticholinergic toxicity | Dry hot skin, dilated pupils, delirium, urinary retention | Supportive care; physostigmine only in selected specialist cases |
Dantrolene is added when NMS is not controlled by stopping the drug and supportive care; it blocks calcium release inside muscle cells, cutting heat production and muscle breakdown.
Cyproheptadine is a 5-HT2A antagonist given by mouth or nasogastric tube.
Concentrated urine argues against primary polydipsia.
Malignant catatonia, with fever and autonomic instability, can overlap clinically with NMS.
A lorazepam response is not specific for catatonia, and electroconvulsive therapy is considered promptly when response is inadequate or life is threatened.
Muscle-generated hyperthermia needs active cooling, because antipyretics alone do not work.
Overdose and toxicity
Poison | Picture | Treatment | Reason |
|---|---|---|---|
Salicylate | Level above 500 mg/L | Urinary alkalinisation to pH 7.5 to 8.5 with IV sodium bicarbonate | A weak acid ionises in the tubule, so excretion rises greatly |
Lithium | Vomiting, coarse tremor, ataxia, confusion | Haemodialysis above 4.0 mmol/L with impaired kidney function, or at any level with reduced consciousness, seizures or arrhythmias | A small ion not bound to plasma proteins, so dialysis clears it efficiently |
Amphetamine | Agitation, tachycardia, heat production | IV diazepam and active cooling | Diazepam calms, cuts heat generation and treats seizures |
Opioid | Coma, respiratory rate of 5, pinpoint pupils | Naloxone, repeated as needed | Competitive opioid antagonist |
Monoamine oxidase inhibitor with tyramine | Throbbing occipital headache, palpitations, severe hypertension | IV phentolamine, an alpha-adrenoceptor antagonist | Displaced noradrenaline acts on alpha-1 receptors |
Naloxone is short-acting, so the patient is observed for renarcotisation after waking.
Opioid tolerance falls within days of detoxification.
Suspected Wernicke's encephalopathy needs prompt parenteral thiamine, but emergency glucose for hypoglycaemia is not delayed while awaiting it.