Opiate overdose

Question 1

What are 3 key effects of opioids?

Answer 1

1. Coma
2. Respiratory depression
3. Pinpoint pupils

Question 2

In what situation is the specific opioid antidote indicated?

Answer 2

if there is coma or bradypnoea

Question 3

What is the specific opioid antidote?

Answer 3

naloxone hydrochloride

Question 4

What must be done once naloxone has been given to treat opioid poisoning?

Answer 4

naloxone has a shorter duration of action than many opioids so close monitoring and repeated injections are necessary according to the respiratory rate and depth of coma

Question 5

What is the BNF recommended dosage for naloxone in opioid overdose?

Answer 5

• initially 400 micrograms IV
• 800 micrograms for up to 2 doses at 1 minute intervals if no response to preceding
• increase to 2mg for 1 dose if still no response (4mg may be required in seriously poisoned patients)
• then review diagnosis

Question 6

How can naloxone be given if repeated administration is required?

Answer 6

continuous intravenous infusion, rate adjusted according to vital signs

Question 7

If IV access is not available how can naloxone be administered?

Answer 7

subcutaneously or intramuscularly

Question 8

What is an example of an opioid which is only partially reversed by naloxone?

Answer 8

buprenorphine

Question 9

What are 2 examples of opioids with long durations of action which may need monitoring for long periods?

Answer 9

1. Methadone
2. Dextropropoxyphene

Question 10

What is an additional problem caused by dextropropoxyphene, in addition to the opioideffects?

Answer 10

produces metabolite norpropoxyphene which also has cardiotoxic effects which may require treatment with sodium bicarbonate or magnesium sulfate (or both)

arrhythmias may occur for up to 12h

Question 11

What are 2 options for treating cardiotoxic effects of norpropoxyphene (metabolic of dextropropoxyphene)?

Answer 11

1. sodium bicarbonate
2. magnesium sulfate