Opioid teaching

Question 1

How do we convert opioid drugs (STEP 2) to morphine?

Answer 1

Divide by 10

Question 2

How do we calculate the dose of breakthrough morphine?

Answer 2

max dose in 24 hours divided by 6

Question 3

Rescue/breakthrough dose

Answer 3

1/6 or 1/10 of total 24hrs dose

Question 4

What is meant by ‘rotation’?

What do we need to remember/consider?

Answer 4

It’s converting one opioid to another

(often convert + reduce dose by 50% to start with)

• It is assuming that bioavailability is same for everyone
• In practice, it’s not: e.g. stronger dose for a young otherwise fit patient vs lower dose for a frail old lady
• It’s better to start off small and then increase as needed

Question 5

Convert:

Morphine PO → Morphine SC

Morphine SC → Morphine PO

Answer 5

Morphine PO → Morphine SC divide by 2

Morphine SC → Morphine PO times 2

Question 6

Convert

Morphine PO → Oxycodone PO

Oxycodone PO → Morphine PO

Answer 6

Morphine PO → Oxycodone PO divide by 1.5

Oxycodone PO → Morphine PO times 1.5

Question 7

Convert

Oxycodone PO → Oxycodone SC

Oxycodone SC → Oxycodone PO

Answer 7

Oxycodone PO → Oxycodone SC divide by 1.5

Oxycodone SC → Oxycodone PO times 1.5

Question 8

What questions to ask if a patient needs an increase in regular opioid dose? (4)

Answer 8

• Did the dose make a patient pain free?
• Did the patient have any side effects → perhaps they reached the max dose (further increase may lead to toxicity)
• Was the need for extra doses due to breakthrough pain or due to incidents (e.g. turning patient in bed, mechanical/external stimuli)?
• Renal and liver function

Question 9

How to increase regular opioid dose? (by how much)

Answer 9

• No more than 50% of an old dose
• Recalculate breakthrough according to new dose

Question 10

What’s max dose of morphine?

Answer 10

There is no maximum dose of morphine

(depends on what patient can tolerate without side effects)

Question 11

What opioid is the safest in combined liver and kidney failure?

Answer 11

Fentanyl