Opioid Overdose

Question 1

Examples of opioids

Answer 1

Morphine, codeine, fentanyl, heroin, methadone, oxycodone, opium

Question 2

Aetiology of opioid overdose

Answer 2

Complications of substance abuse
Unintentional overdose
Self harm and suicidal intent
Therapeutic drug error

Recent abstinence increases risk of overdose

Question 3

What is the pathophysiology of opioid overdoses

Answer 3

Opioids work by suppressing GABA release
This causes euphoria as it increases dopamine release
It also interferes with central chemoreceptors that respond to CO2 - hypercapnic drive is impaired -> resp. depression
Also causes N+V, miosis, GI symptoms (constipation) and urticaria via GABA

Question 4

Which route of opioid admin is most potent

Answer 4

Injection as it bypasses first-pass metabolism by the liver

Question 5

Presenting symptoms of an opiate overdose

Answer 5

Altered mental status (drowsiness, sleepiness)
Nausea and vomiting
Constipation
Abdominal pain
Pink frothy sputum, cough, fever, SOB (ARDS)
Seizure

Late: low GCS and coma

Question 6

Signs of opiate overdose

Answer 6

Miosis - pin-point pupils 
Bradypnoea 
Hypotension 
Bradycardia
Fresh needle marks, old track marks, drug paraphernalia

Question 7

Investigations for opiate overdose

Answer 7

Naloxone trial: should have rapid reversal of symptoms

Opioid urine screen: +ve for opioids
ECG: abnormal, done due to resp. compromise

CXR: normal cardiac silhoutte, infiltrates seen
AXR/CT: visualisation of packets of drugs

Question 8

Management for opiate overdose

Answer 8

IV naloxone