Need help with narcotic conversions

[FenderBender]

I am a pharmacy student and I need some help with narcotic conversions. It is a little confusing to me. Can someone post the steps to converting to a different opioid and also provide an example? I would appreciate it greatly! I already have the narcotic conversion chart, but everything else I'm not sure about!

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[TheAssMan]

I am a pharmacy student and I need some help with narcotic conversions. It is a little confusing to me. Can someone post the steps to converting to a different opioid and also provide an example? I would appreciate it greatly! I already have the narcotic conversion chart, but everything else I'm not sure about!

WORKSHEET
1. Determine total Current Long Acting medication
1a Determine the total daily usage of all CURRENT long-acting medications Mg Each dose x # frequency/day
1b Write down conversion factor for CURRENT long acting medicine
1c Write down conversion factor for NEW long acting medicine
1d Convert current long-acting medication to NEW desired long-acting medication (per day) (Value in #1a) x (Value in #1c)/(Value in #1b)
2. Determine total Current Short Acting medication
2a Determine the total daily usage of all CURRENT short - acting medications Mg Each dose x # doses actually taken/day
2b Write down conversion factor for CURRENT short acting medicine
2c Write down conversion factor for NEW long acting medicine
2d Convert current long-acting medication to NEW desired long-acting medication (Value in #2a) x (Value in #2c)/(Value in #2b)
3. Determine Total Daily Opioid Usage in terms of NEW Long Acting
3 New Total Daily Opioid Dose Add (Value in #1d) + (Value in #2d)

4. Determine NEW Long Acting Dose
4a Determine New Long Acting portion of total daily dose (75% of daily dose) Multiply (Value in #3) x 0.75
4b Write down frequency of NEW long acting agent per day. (2: bid, 3: tid, 24: qhr, etc)
4c Determine new Long Acting dosing Divide (Value in #4a)/ (Value in #4b)

5. Determine NEW Short Acting Dose
5a Determine Short Acting portion of total daily dose (25% of daily dose) Multiply (Value in #3) x 0.25
5b Determine new Short Acting dose
(assuming 5 rescues per day) Divide (Value in #5a) by 5
6. Convert Short Acting Dose
6a Write down conversion factor for NEW desired short acting medicine
6b Convert this short-acting medication to NEW desired short acting medicine (Value in #5b) X (Value in #6a)/(Value in #2c)

7. New Long Acting Dose
Value in #5b Given at desired frequency (Value in #4b)
8. New Short Acting Dose
Value in #6b Given q4hr prn


As an example, imagine that a patient takes MS Contin 200mg po bid and Dilaudid rescues 8mg each time, 10 times per day. How much Fentanyl patch with morphine rescues is required?

1. Determine total Current Long Acting medication
1a Determine the total daily usage of all CURRENT long-acting medications Mg Each dose x # frequency/day
(200mg ) x 3/day = 600mg/day
1b Write down conversion factor for CURRENT long acting medicine 30
1c Write down conversion factor for NEW long acting medicine 0.2
1d Convert current long-acting medication to NEW desired long-acting medication (per day) (Value in #1a) x (Value in #1c)/(Value in #1d)
(600) X (0.2)/(30)= 4 mg/day
2. Determine total Current Short Acting medication
2a Determine the total daily usage of all CURRENT short - acting medications Mg Each dose x # doses actually taken/day
(8mg) x (10) = 80mg/day
2b Write down conversion factor for CURRENT short acting medicine 8
2c Write down conversion factor for NEW long acting medicine 0.2
2d Convert current long-acting medication to NEW desired long-acting medication (Value in #2a) x (Value in #2c)/(Value in #2b)
(80) x (0.2)/8= 2mg/day
3. Determine Total Daily Opioid Usage in terms of NEW Long Acting
3 New Total Daily Opioid Dose Add (Value in #1d) + (Value in #2d)
(4) + (2) = 6mg/day

4. Determine NEW Long Acting Dose
4a Determine New Long Acting portion of total daily dose (75% of daily dose) Multiply (Value in #3) x 0.75
(6) x 0.75) = 4.5mg/day
4b Write down frequency of NEW long acting agent per day. (2: bid, 3: tid, 24: qhr, etc)
(24)
4c Determine new Long Acting dosing Divide (Value in #4a)/ (Value in #4b)
(4.5)/(24)= 0.1875 mg/hr =
187.50 mcg/hr Fentanyl

5. Determine NEW Short Acting Dose
5a Determine Short Acting portion of total daily dose (25% of daily dose) Multiply (Value in #3) x 0.25
(6 mg) x (0.25)= 1.5mg
5b Determine new Short Acting dose
(assuming 5 rescues per day) Divide (Value in #5a) by 5
(1.5 mg) /5 = 0.3mg
6. Convert Short Acting Dose
6a Write down conversion factor for NEW desired short acting medicine 30
6b Convert this short-acting medication to NEW desired short acting medicine (Value in #5b) X (Value in #6a)/(Value in #2c)
(0.3) x (30)/(0.2)=45 mg

7. New Long Acting Dose
Fentanyl Patch 187.50 mcg/hr Given at desired frequency (Value in #4b)
8. New Short Acting Dose
Morphine PO 45 mg Q4hr prn

 

[FenderBender]

Wow, that's a lot. Thanks for answering, but I was looking for something like this. Can someone check and see if my work is correct?



Example: Patient is on hydromorphone PCA with a constant rate infusion of 0.5 mg/hr IV and a demand bolus of 0.1 mg with a lock-out period of 10 minutes (which she has used 12 times in the past 24 hours). You are asked to convert her to oral Oxycontin before discharging her home.

1) Calculate 24 hour dose of medication.
2) Convert the 24 hour equivalent dose of morphine.
3) Convert equivalent dose to desired opioid.
4) Take into account incomplete opioid cross-tolerance (50-75%) and recalculate a new 24 hour dose.
5) Recommend a fast acting breakthrough medication that is equal to 15-20% of the 24 hour base dose.

1)

0.5 mg/hr x 24 hrs = 12 mg

0.1 mg x 12 = 1.2 mg

12 mg + 1.2 mg = 13.2 mg hydromorphone total


2)

13.2 x
----- = ----
1.5 10

x = 88 mg IV morphine


3)

88 x
---- = ----
10 30

x = 264 mg PO morphine

264 x
----- = ----
30 20

x = 176 mg PO oxycodone


4)

.50 x 176 mg = 88 mg PO oxycodone

Recommended Oxycontin Dose: 40 mg PO q 12 hours


5)

.15 x 176 mg = 26.4 mg PO oxycodone for breakthrough pain

Recommended Breakthrough Medication: Oxycodone 5 mg PO q 6 hours

 

[mid|ine]

There is a much simpler formula.

If a dose equivalent conversion is required = patient is on to much narcotics

 

[PMR 4 MSK]

There is a much simpler formula.

If a dose equivalent conversion is required = patient is on to much narcotics

lol

 

[Ligament]

There is a much simpler formula.

If a dose equivalent conversion is required = patient is on to much narcotics

Totally true in 80% of cases!