Opioid Switching

Question 1

What are the 1^st line opioids?

Answer 1

• Codeine (either alone or combined with paracetamol in co-codamol) and tramadol are weak opioids which may be suitable for certain patient groups with moderate to severe pain.
• Morphine is 1st line strong opioid that should be used when managing severe pain.
  
  • It can be given orally and is available in both immediate and modified-release formulations (often abbreviated to I/Rand M/R respectively.
  • Morphine can also be given as a single bolus dose by SC, IM or IV route or added to a syringe driver which delivers analgesia slowly by infusion over a 24h period.

Question 2

What are the 2^nd line opioids?

Answer 2

• Oxycodone is useful if morphine is not tolerated and can be given orally, SC and IV.
• Fentanyl is useful for topical application (patch) in patients with severe, stable pain and in patients who have difficulty swallowing oral medication.
  
  • As it can take a few hours to reach maximal analgesic effect it is not useful for those patients experiencing severe acute pain.
  • Fentanyl tends to be less constipating and more appropriate for patients with renal impairment.
  • It is also available as an injection (reserved usually for use in ICU or during operations) and buccal /sublingual/nasal formulations (for breakthrough cancer pain).

Question 3

What are the 3^rd and 4^th line opioids?

Answer 3

• These include:
  
  • Alfentanil
  • Methadone
  • Intranasal or buccal fentanyl
• These are used under specialist advice only.

Question 4

What is the standard dose of a strong opioid for breakthrough pain?

Answer 4

• The standard dose of strong opioids for breakthrough pain is ROUGHLY 1/6-1/10 of the regular 24h dose, repeated every 2-4h as required.
• This is subject to inter-patient variability so should be tailored to the individual.
• Dose conversions should be conservative, and doses are usually rounded down.
• Any drug / dose / formulation / route adjustments should be monitored closely, taking extra care if patient is frail, elderly or has renal / hepatic impairment.

Question 5

How do you convert oral morphine to SC morphine?

Answer 5

Divide by 2

Question 6

How do you convert oral morphine to SC diamorphine?

Answer 6

Divide by 3

Question 7

How do you convert oral morphine to oral oxycodone?

Answer 7

Divide by 2

Question 8

How do you convert oral morphine to SC oxycodone?

Answer 8

Divide by 4

Question 9

What is the equivalent fentanyl patch to 30-60mg of oral morphine?

Answer 9

Fentanyl patch 12µg / hour

Question 10

What is the equivalent fentanyl patch to 60-90mg of oral morphine?

Answer 10

Fentanyl patch 25µg / hour

Question 11

How do you convert oral morphine to SC alfentanil?

Answer 11

Divide by 30

Question 12

How do you convert oral morphine to oral hydromorphone?

Answer 12

Divide by 5-7.5

Question 13

How do you convert oral morphine to SC hydromorphone?

Answer 13

Divide by 10

Question 14

How do you convert oral oxycodone to SC oxycodone?

Answer 14

Divide by 2

Question 15

How do you convert oral oxycodone to oral morphine?

Answer 15

Multiply by 2

Question 16

How do you convert oral oxycodone to SC diamorphine?

Answer 16

Divide by 1.5

Question 17

How do you convert oral oxycodone to SC alfentanil?

Answer 17

Divide by 15

Question 18

How do you convert oral oxycodone to oral hydromorphone?

Answer 18

Divide by 4