OPIOID CONVERSIONS

OPIOID CONVERSIONS
Sarah Beth Harrington, MD
October 2, 2007
Resident Skills Session

Objectives
1. Review basic principles for prescribing for long
and short acting po opioids.
2. Demonstrate competence in calculating opioid
dose conversions using standard published
conversion ratios.
3. Calculate starting dose of methadone using
common clinical scenerios
4. Compare costs of different opioids when
making prescription decisions

• Equianalgesic ratios serve as rough
clinical guides
• Always take into account:
•Age
• Renal/Hepatic/Pulmonary function
• Opioid tolerance/ naivety

PRESCRIBING LONG-ACTING
OPIOIDS
1. Short Long acting when pain wellcontrolled
PP: Use equianalgesic dosing
Avoid combo agents
Bowel regimen!
Instructions:
1. Calculate mg opioid in 24 hrs convert to SR
2. Calculate rescue dose (IR); ~ 10-20% total daily dose

Mr. Smith (Case 1)
Case 1:
10mg oxycodone 6 times/day = 60mg oxycodone in 24 hrs
Equivalent SR oxycodone= Oxycontin 30mg q12h
Rescue dose – 10% (60mg) = 6 mg
20% (60mg) = 12mg
ANSWER:
Oxycontin 30mg q12h with Oxycodone 5-10mg q4h prn

PRESCRIBING LONG-ACTING
OPIOIDS
2. Short Long-acting at higher dose
- Use for: unrelieved/partially relieved chronic pain
Instructions:
1. Calculate mg opioid used in 24 hrs and convert to
long-acting opioid
2. Increase long-acting opioid by 50%
3. Check pill dose availability
4. Adjust rescue dose [10-20% new daily dose]

Mr. Smith (Case 2)
10mg oxycodone 6 times/day = 60mg oxycodone in 24 hrs
*Increase by 50%
[ 60mg +(60mg X 50%)] =60+30= 90mg oxycodone in 24h
Equivalent SR oxycodone = 45mg q12h
Check pill availability = Oxycontin 40mg q12h
Adjust rescue dose 10% 80mg = 8 mg
20% 80mg = 16mg
Oxycontin 40mg q12h with 10-15mg Oxycodone q4h prn

PRESCRIBING LONG-ACTING
OPIOIDS
3. Using rescue doses to increase SRopioid
PP: Can safely escalate opioid dose in pt with constant
pain after 24-48 hrs
If total drug taken as rescue dose in 24hr is > 25% total
SR dose, increase the SR dose by that amount

Mr. Smith (Case 3)
Total Oxycodone/day =
80mg (SR) + 40mg (IR) = 120mg oxycodone/day
New Oxycontin dose = 60mg q12h
Rescue dose 10% 120mg = 12 mg
20% 120mg = 24 mg
Oxycontin 60mg q12h with 15-20mg oxycodone
q4h prn

Ms. X
15mg Morphine IR X 8 doses = 120mg
morphine/day
SR = MS Contin 60mg q12h
Rescue doses 10% 120mg = 12mg
20% 120mg = 24mg
MS Contin 60mg q12h + MS IR 15-20mg q3h prn

Ms. Y
20 mg oxycodone X 5 doses = 100mg
oxycodone/day
Increase by 50% =
100mg + (50% (100mg)) = 100 +50 = 150mg
oxycodone/day
Check pill availability - 80mg Oxycontin q12h
Rescue dose – 10% 160mg = 16mg
20% 160mg = 32 mg
Answer:
Oxycontin 80mg q12h + 15-30mg oxycodone q4h prn

Mr. Z
60mg (SR) +60mg (IR) = 120mg total MS/day
Convert to long-acting = MS Contin 60mg q12h
Rescue dose – 10% (120mg) = 12 mg
20% (120mg) = 24 mg
Answer:
MS Contin 60mg q12h + 15-20mg MS IR q4h prn

CHANGING OPIOID AGENTS
PP: Remember - Incomplete cross-tolerance
between different opioids
Start new opioid at ½-⅔ of the calculated
equianalgesic dose.
Instructions:
1. If working with SR opioid, calculate 24 hr
current opioid dose
2. Use equianalgesic ratio to calculate new opioid
dose
3. Reduce dose by ½-⅔ for cross tolerance

Mrs. T
80mg oxycontin q12h=160mg total oxycodone/day
⅔ (160mg) ≈ 100 mg morphine/day
(Check pill availability) – MS Contin 45mg q12h
Rescue dose 10% 90mg = 9 mg
20% 90mg = 18mg
MS Contin 45mg q12h + MS IR 15mg q4h prn

Quick TIP
• OXYCODONE MORPHINE
Easy! Take current dose and reduce by ½-⅔

Mr. X
200mg morphine (SR) + 100mg (IR) = 300mg total
morphine/day
Reduce for cross tolerance: ½ (100mcg/hr patch) =
50mcg/hr Fentanyl patch

Mr. Z
Convert MS IR Dilaudid
4-5 mg po morphine = 1mg po dilaudid
⅔ (6mg) = 4 mg po dilaudid
4mg po dilaudid q4h prn

Ms. B
⅔ (225 mg) ≈ 150 mg morphine/day
75 mg MS Contin q12h
Breakthrough - 10% 150 = 15 mg
20% 150 = 30 mg
MS Contin 75 mg q12h with 15-30mg MS IR prn

Mr. C
Oxycodone in 24 hrs =
40mg (SR) + 20mg (IR) = 60mg oxycodone/day
60mg oxycodone/day = 60mg morphine/day
½ (60mg ) =30mg po morphine/day
=15mg MS Contin q12h
Breakthrough – 10% 30mg = 3 mg
20% 30mg = 6 mg
Answer: MS Contin 15 mg q12h + MS IR 5 mg prn

METHADONE
PP: Cheap, effective, neuropathic pain
Long-acting, would wait 3 days before
titrating dose
Pay attention to ratios
Decrease by 50% for cross tolerance

Mr. D
400mg (SR)+200mg (IR) = 600mg morphine/day
10mg po morphine = 1mg po methadone
50% (60mg methadone/day) = 30mg methadone/day
10mg po methadone q8h

Mr. X
900mg MS Contin q12h = 1800mg morphine/day
50% (90 mg methadone) = 45mg po methadone/day
Methadone 15mg q8h

Ms. Y
24 hr morphine = 60mg X 6 doses = 360mg po
morphine/day
50% (36 mg) = 18 mg po methadone/day
18mg + 15 mg = 33mg po methadone/day
New dose of methadone = 10mg q8h

Multiple opioid conversions
PP: Convert everything to morphine
Decrease for cross tolerance at the end

Mr. Y
MS Contin 100mg q8h = 300mg morphine/day
Oxycodone 30mg/day = 30mg po morphine/day
Dilaudid po16mg/day = 80mg po morphine/day
Fentanyl patch 50mcg/hr = 150mg morphine/day
-------------------------------------------------------------------
Total morphine equivalent/day = 560mg/day

50% (56 mg methadone/day) = 28 mg methadone/day
Answer: 10mg po methadone q8h +4-8mg po dilaudid prn

CHANGING OPIOID ROUTE:
SAME DRUG
PP: Do NOT stop long-acting opioid
Start equivalent parenteral basal dose

Ms. T
60mg MS Contin q12h = 120mg po morphine/day
40mg IV morphine/24 hr = 1.6mg IV morphine/hr

Mr. M
EASY!!
20mg po methadone q8h
10mg IV methadone q8h

CHANGING OPIOID ROUTE:
DIFFERENT DRUG
PP:
Easiest to convert to morphine 1 st
Remember to reduce ½-⅔ for X-tolerance

Mr. A
Oxycontin 120mg q12h = 240mg oxycodone/day
240mg 240 mg 80mg IV morphine/
oxycodone/day po morphine/day day
16 mg IV dilaudid/24h = 0.67 mg IV dilaudid/hr
⅔ (0.67mg/hr) = 0.4 mg IV dilaudid/hr

Miss D
90 mg po 30mg IV 6 mg IV
morphine morphine dilaudid
⅔ (6mg) = 4 mg IV dilaudid **

Ms. P
60mg IV 300mg IV 900 mg po
dilaudid/day morphine/day morphine/day
50% (90 mg) = 45mg po methadone/day
Answer: 15 mg po methadone q8h

Ms. P
Other answers:
300mg MS Contin q12h + 60mg MS IR prn
Fentanyl patch 200 mcg/hr
WHY is Methadone the better choice??

Cost Comparison
DRUG
COST per
PILL
Oxycodone 5 mg $0.33
Oxycodone ER 20mg $2.33
Oxycontin 20mg $3.48
Oxycontin 160 mg $15.45
Morphine sulfate IR 15mg $0.34
Morphine sulfate ER15mg $0.75
MS Contin 15 mg $1.70

Cost Comparison
DRUG
COST per
PILL
Hydromorphone 4 mg $0.53
Dilaudid 4 mg $1.19
Fentanyl 50mcg/hr patch $24.39
Duragesic 50mcg/hr $33.20
patch
Methadone 5 mg $0.19

Conclusion
• Avoid combo agents
• Bowel regimen
• Rescue dose -10-20% total daily dose
• Incomplete X-tolerance between opioids
• When changing agents, reduce by ½-⅔
• Methadone = good
• Do not ever stop a pt’s long-acting opioid
• Remember $$

Resources
Palliative Care Consult Team
- Call N4N (6-1295)
- Page–Dr. Swetz, Dr. Patel, Pat Coyne
- Place consult in Cerner – Pain CNS