Overdose and poisoning

Paracetamol Overdose

Salicylate Overdose

Organophosphate Poisoning

Recreational Drugs

Management

The table below outlines the main management for common overdoses:

Toxin Treatment
Paracetamol Management
• activated charcoal if ingested < 1 hour ago
• N-acetylcysteine (NAC)
• liver transplantation
Salicylate Management
• urinary alkalinization with IV bicarbonate
• haemodialysis
Opioid/opiates Naloxone
Benzodiazepines Flumazenil
The majority of overdoses are managed with supportive care only due to the risk of seizures with flumazenil. It is generally only used with severe or iatrogenic overdoses.
Tricyclic antidepressants Management
• IV bicarbonate may reduce the risk of seizures and arrhythmias in severe toxicity
• arrhythmias: class 1a (e.g. Quinidine) and class Ic antiarrhythmics (e.g. Flecainide) are contraindicated as they prolong depolarisation. Class III drugs such as amiodarone should also be avoided as they prolong the QT interval. Response to lignocaine is variable and it should be emphasized that correction of acidosis is the first line in management of tricyclic induced arrhythmias
• dialysis is ineffective in removing tricyclics
Lithium Management
• mild-moderate toxicity may respond to volume resuscitation with normal saline
• haemodialysis may be needed in severe toxicity
• sodium bicarbonate is sometimes used but there is limited evidence to support this. By increasing the alkalinity of the urine it promotes lithium excretion
Warfarin Vitamin K, prothrombin complex
Heparin Protamine sulphate
Beta-blockers Management
• if bradycardic then atropine
• in resistant cases glucagon may be used
Ethylene glycol Management has changed in recent times
• ethanol has been used for many years
• works by competing with ethylene glycol for the enzyme alcohol dehydrogenase
• this limits the formation of toxic metabolites (e.g. Glycoaldehyde and glycolic acid) which are responsible for the haemodynamic/metabolic features of poisoning
fomepizole, an inhibitor of alcohol dehydrogenase, is now used first-line in preference to ethanol
• haemodialysis also has a role in refractory cases
Methanol poisoning Management
fomepizole or ethanol
• haemodialysis
Organophosphate insecticides Management
atropine
• the role of pralidoxime is still unclear - meta-analyses to date have failed to show any clear benefit
Digoxin Digoxin-specific antibody fragments
Iron Desferrioxamine, a chelating agent
Lead Dimercaprol, calcium edetate
Carbon monoxide Management
• 100% oxygen
• hyperbaric oxygen
Cyanide Hydroxocobalamin; also combination of amyl nitrite, sodium nitrite, and sodium thiosulfate

Beta-blocker overdose

Features

Management

Haemodialysis is not effective in beta-blocker overdose