MANAGEMENT OF

ANTIPSYCHOTIC

OVERDOSE

Presented by:

Sunil Kumar Daha

ANTIPSYCHOTIC DRUGS

Inhibition of α-adrenergic receptors

Inhibition of dopaminergic receptors

Inhibition of histaminergic receptors

Inhibition of muscarinic receptors

Inhibition of serotonergic receptors

Inhibition sodium， potassium， and

calcium channels

COMMON USES

Antipsychotic

Control nausea and vomiting

Gastro esophageal disorders

SYMPTOMS

Anti-cholinergic features (tachycardia,

hypertention, confusion, hallucination,

sedation, myoclonus, fever, diplopia,

mydriasis, lleus, palpable bladder,

flushing, dry mouth

Serotogenic features (tachycardia, <-

>BP, confusion, hallucination, sedation,

coma, shivering, myoclonus, fever,

diarrhea, comitting, flushing)

Prolonged QT interval, torsades de

pointes

HYPERKINETIC MOVEMENT

DISORDER

Acute

Sub acute

Chronic

ACUTE SYMPTOMS

minutes of exposure

dystonia

generalized in children and focal in

adults (blepharospasm, torticollis,

oromandibular dystonia)

IV benzodiazpine (diazepam 10-20

mg, lorazepam 2-4 mg)

Dopamine agonist

SUBACUTE SYMPTOMS

Akathisia

motor restlessness with a need to

move that is alleviated by movement

removing the offending agent

benzodiazepine， anticholinergics，beta blockers or dopamine agonists.

CHRONIC SYMPTOMS

Tardive dyskinesia

Tardative dystonia: axial muscles, trunk,

pelvis

Tardive akathisia

Tardive Tourette's

Tardive tremor syndrome

Neuroepileptic Malignant Syndrome

(NMS)

TARDATIVE SYNDROMES

Tardive dyskinesia (TD)

choreiform movements in mouth, lips, tongue, trunk, limbs, respiratory muscles may also be affected

remits within 3 months of stopping the drug， and most patients gradually improve over the course of several years

abnormal movements may also develop or worsen after stopping the offending agent.

Atypical antipsychotics: lower risk of TD

TARDATIVE SYNDROMES…

Younger patients have a lower risk

Elderly, females, previous organic cerebral dysfunction at greater risk

Chronic use with increased risk (metoclopramide for more than 12 weeks)

Can be permanent and resistant to treatment

atypical neuroleptics should be the preferred

Treatment: Stop offending agent

Patient with traditional antipsychotic replace with an atypical antipsychotic (avoid acute

Neuroepileptic Malignant

Syndrome (NMS)

Acute or subacute onset of:o muscle rigidityo elevated temperatureo altered mental statuso tachycardiao labile blood pressureo renal failureo elevated creatine kinase levels• Evolve within days or weeks after strating

drug• Abrupt withdrawal of dopaminergic

medications in PD

NMS…

Stop offending antipsychotic drug

Introduction of a dopaminergic agent

(dopamine agonist or levodopa),

dantrolene, benzodiazepine.

Antipyretics, cooling blankets, hydration,

electrolyte replacement, control of renal

function and blood pressure.

MANAGEMENT

Management of ABC

Activated charcoal if within 1 hr of

ingestion

Cardiac monitoring for 6 hrs

CVS: MgSO4, 2g IV over 1-2 min

Avoid class IA, IC antiarrhythmics

NaHCO3

REFERENCES

Harrison’s Principles of Internal

Medicine, 19th edition

Davidson’s Principles and practise of

Medicine, 22nd edition

https://www.ncbi.nlm.nih.gov/pubmed/

22668123