Description

Tables showing equianalgesic doses of narcotic agents can be used to determine the dose of a different narcotic with approximately the same amount of analgesia to the current medication.


NOTE: Problems in comparing equianalgesic narcotic doses:

(1) duration of patient exposure: acute/intermittent vs chronic/continuous usage

(2) route: oral vs parenteral vs transdermal vs rectal

(3) severity of underlying pain and whether it was established before starting analgesia

(4) duration of drug effect: normal kinetics vs extended dose release

(5) age, body weight and comorbid conditions of the patient

(6) interindividual variability in relative potency for each narcotic agent

(7) the protocol (single dose, infusion, multiple doses) by which the drug comparison was conducted

 

NOTE: All of the doses were adjusted from the original source data to be equivalent to 10 mg oral morphine, chronic/continuous exposure, for an adult.

 

Morphine

Extended Oral

Parenteral

Young (1996)

 

3.3 mg

Portenoy (1986)

 

3.3 mg

AHCPR (1992)

30 – 40 mg

3.3 mg

VITAS (1999)

30 mg

0.8 mg

Cherny (2001)

 

3 – 5 mg

Magrum (1996)

 

3.3 mg

use in program

30 mg

3.3 mg

 

where:

• The conversion from oral to parenteral morphine is 6:1 when with acute and intermittent use, but 2:1 or 3:1 with chronic and continuous use.

• The equianalgesic dose of oral morphine for acute, intermittent doses is 60 mg vs 30 mg for chronic, continuous doses. This means that you need to reduce the drug dose if you go from infrequent, intermittent dosing to continuous dosing.

 

Hydromorphone

Oral

Parenteral

Young (1996)

3 – 4 mg

0.33 mg

Portenoy (1986)

2.5 mg

0.5 mg

AHCPR (1992)

2.5 mg

0.5 mg

VITAS (1999)

3.0 mg

0.1 mg

Cherny (2001)

2.0 mg

1.0 mg

Magrum (1996)

2.5 mg

0.5 mg

use in program

2.5 mg

0.5 mg

 

 

Oxymorphone

Oral

Rectal

Parenteral

Portenoy (1986)

2.0 mg

 

0.33 mg

AHCPR (1992)

 

 

0.33 mg

Magrum (1996)

 

3.3 mg

0.33 mg

use in program

 

 

0.33 mg

 

 

Codeine (with ASA or Tylenol)

Oral

Parenteral

Young (1996)

60 mg

20 – 40 mg

Portenoy (1986)

66 mg

43 mg

AHCPR (1992)

66 mg

43 mg

VITAS (1999)

60 mg

 

use in program

60 mg

40 mg

 

 

Hydrocodone

Oral

Parenteral

Young (1996)

4 mg

0.6 mg

AHCPR (1992)

5 mg

 

use in program

5 mg

 

 

 

Oxycodone

Oral

Extended Oral

Parenteral

Young (1996)

16 mg

 

 

Portenoy (1986)

10 mg

 

5 mg

AHCPR (1992)

10 mg

 

 

VITAS (1999)

7.0 mg

20 mg

 

Cherny (2001)

7.5 mg

 

3.8 mg

Magrum (1996)

10 mg

 

5.0 mg

use in program

10 mg

 

5 mg

 

 

Fentanyl

Transdermal

Parenteral

Young (1996)

 

16 micrograms

Portenoy (1986)

 

33 micrograms

AHCPR (1992)

 

 

VITAS (1999)

25 micrograms

8 micrograms

Cherny (2001)

 

16.7 micrograms

Magrum (1996)

 

33 micrograms

use in program

 

16 micrograms

 

 

Leverphanol

Oral

Parenteral

Portenoy (1986)

1.33 mg

0.66 mg

AHCPR (1992)

1.33 mg

0.66 mg

VITAS (1999)

1 mg

 

Magrum (1996)

1.33 mg

0.66 mg

use in program

1.33 mg

0.66 mg

 

 

Meperedine

Oral

Parenteral

Young (1996)

100 mg

16 - 33 mg

Portenoy (1986)

100 mg

25 mg

AHCPR (1992)

100 mg

33.3 mg

VITAS (1999)

100 mg

6 mg

Magrum (1996)

100 mg

25 mg

use in program

100 mg

25 mg

 

where:

• Meperedine has a number of problems as an analgesic agent and does not appear to be recommended for control of terminal cancer pain. A toxic metabolite may accumulate in renal failure.

 

Methadone

Oral

Parenteral

Young (1996)

8 - 10 mg

3.3 mg

Portenoy (1986)

6.6 mg

3.3 mg

AHCPR (1992)

6.6 mg

3.3 mg

VITAS (1999)

4 mg

 

Cherny (2001)

varies with morphine dose

 

Magrum (1996)

6.6

3.3 mg

use in program

6.6 mg

3.3 mg

 

In the implementation:

(1) Each opioid is divided by its equianalgesic dose to give a number of "analgesic units" that can be summed to give a total for 24 hours.

(2) The number of units can then be multiplied by the equianalgesic dose for a single agent to give the amount of that agent needed to provide "equivalent" analgesia.

 

NOTE: The equianalgesic dose may not be the dose of the new drug that you should choose to administer to the patient. If going from intermittent to continuous dosing it may be necessary to use a lower dose, while going from continuous to intermittent may require a higher dose. Usually a lower dose is selected to avoid adverse effects and to rely on rescue doses to control the pain.


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