Opioid Conversion & MME Practice Problems
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Opioid math converts between opioids and routes using an equianalgesic table anchored to 30 mg of oral morphine, and totals a regimen in morphine milligram equivalents (MME) for safety review. Fentanyl patch selection is a separate range-based lookup.
FormulasProportion from the equianalgesic table (30 mg PO morphine = anchor)MME/day = daily dose × (30 ÷ that drug's equianalgesic dose)
Worked exampleOxycodone 10 mg three times daily = 30 mg/day. Table: 20 mg oxycodone ≈ 30 mg morphine, so MME = 30 × (30 ÷ 20) = 45 MME/day.
90 MME/day is the common safety-review threshold; watch route differences. The same drug by a different route has a different number.
10 Opioid Conversion & MME practice problems with worked solutions
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Problem 1: Equianalgesic Conversion
A patient is receiving 10 mg/day of morphine (IV). Using the equianalgesic table below, what is the equivalent daily dose of hydrocodone (PO) in mg/day, before any cross-tolerance reduction?
| Opioid | PO (mg) | IV (mg) |
|---|
| morphine | 30 | 10 |
| hydromorphone | 7.5 | 1.5 |
| oxycodone | 20 | , |
| hydrocodone | 30 | , |
| codeine | 200 | , |
| meperidine | 300 | 75 |
| fentanyl | , | 0.1 (= 100 mcg) |
Round your answer to one decimal place.
Answer 30.0 mg/day
Solution- Pull the two relevant rows, drug AND route: morphine (IV) = 10 mg ≈ hydrocodone (PO) = 30 mg.
- Set up the proportion: 10 mg / 30 mg = 10 mg / x.
- x = 10 × 30 ÷ 10 = 30 mg/day = 30 mg/day of hydrocodone (PO).
- Rounded as the question asks: 30.0 mg/day.
In practice the calculated dose is reduced by 25 to 50% for incomplete cross-tolerance, exam questions specify whether they want the raw conversion or the reduced dose. Meperidine bonus fact: normeperidine accumulation (seizure risk) makes it inappropriate for chronic pain, which exams like to test.
Problem 2: Fentanyl Patch
A patient's opioid regimen totals 135 mg/day of oral morphine equivalents. Using the conversion table below, which fentanyl patch strength (mcg/hr) is appropriate? This table comes from the product labeling and already builds in the conservative conversion factor, so no further cross-tolerance reduction is applied.
| Oral morphine (mg/day) | Fentanyl patch (mcg/hr) |
|---|
| 60 to 134 | 25 |
| 135 to 224 | 50 |
| 225 to 314 | 75 |
| 315 to 404 | 100 |
Round your answer to the nearest whole number.
Answer 50 mcg/hr
Solution- Find the range containing 135 mg/day → 135 to 224 mg/day.
- That row corresponds to the 50 mcg/hr patch.
- Rounded as the question asks: 50 mcg/hr.
Patch selection is a table LOOKUP rather than a proportion, so never interpolate between rows. The Duragesic table is deliberately conservative, so you do NOT subtract a further 25 to 50% on top of it. Patches are changed every 72 hours and are for opioid-tolerant patients only, and exams test both of those facts.
Problem 3: MME
A patient takes oxycodone (PO) 30 mg, 2 times daily. Using the equianalgesic table below, what is the total daily dose in morphine milligram equivalents (MME/day)?
| Opioid | PO (mg) | IV (mg) |
|---|
| morphine | 30 | 10 |
| hydromorphone | 7.5 | 1.5 |
| oxycodone | 20 | , |
| hydrocodone | 30 | , |
| codeine | 200 | , |
| meperidine | 300 | 75 |
| fentanyl | , | 0.1 (= 100 mcg) |
Round your answer to the nearest whole number.
Answer 90 MME/day
Solution- Find the right cell, drug AND route: 20 mg oxycodone (PO) ≈ 30 mg morphine (PO).
- Daily dose: 30 mg/dose × 2 doses/day = 60 mg/day.
- Proportion: 20 mg / 30 mg = 60 mg / x → x = 60 mg/day × 30 mg ÷ 20 mg = 90 MME/day.
- Rounded as the question asks: 90 MME/day.
MME is just an equianalgesic conversion with 30 mg oral morphine as the anchor. 90 MME/day is the common review threshold in opioid safety guidance. MME factors are defined for ORAL opioids; a parenteral dose must first be converted to its oral equivalent, which is why the CDC table has no IV column.
Problem 4: Equianalgesic Conversion
A patient is receiving 15 mg/day of morphine (IV). Using the equianalgesic table below, what is the equivalent daily dose of meperidine (IV) in mg/day, before any cross-tolerance reduction?
| Opioid | PO (mg) | IV (mg) |
|---|
| morphine | 30 | 10 |
| hydromorphone | 7.5 | 1.5 |
| oxycodone | 20 | , |
| hydrocodone | 30 | , |
| codeine | 200 | , |
| meperidine | 300 | 75 |
| fentanyl | , | 0.1 (= 100 mcg) |
Round your answer to one decimal place.
Answer 112.5 mg/day
Solution- Pull the two relevant rows, drug AND route: morphine (IV) = 10 mg ≈ meperidine (IV) = 75 mg.
- Set up the proportion: 10 mg / 75 mg = 15 mg / x.
- x = 15 × 75 ÷ 10 = 112.5 mg/day = 112.5 mg/day of meperidine (IV).
- Rounded as the question asks: 112.5 mg/day.
In practice the calculated dose is reduced by 25 to 50% for incomplete cross-tolerance, exam questions specify whether they want the raw conversion or the reduced dose. Meperidine bonus fact: normeperidine accumulation (seizure risk) makes it inappropriate for chronic pain, which exams like to test.
Problem 5: Fentanyl Patch
A patient's opioid regimen totals 70 mg/day of oral morphine equivalents. Using the conversion table below, which fentanyl patch strength (mcg/hr) is appropriate? This table comes from the product labeling and already builds in the conservative conversion factor, so no further cross-tolerance reduction is applied.
| Oral morphine (mg/day) | Fentanyl patch (mcg/hr) |
|---|
| 60 to 134 | 25 |
| 135 to 224 | 50 |
| 225 to 314 | 75 |
| 315 to 404 | 100 |
Round your answer to the nearest whole number.
Answer 25 mcg/hr
Solution- Find the range containing 70 mg/day → 60 to 134 mg/day.
- That row corresponds to the 25 mcg/hr patch.
- Rounded as the question asks: 25 mcg/hr.
Patch selection is a table LOOKUP rather than a proportion, so never interpolate between rows. The Duragesic table is deliberately conservative, so you do NOT subtract a further 25 to 50% on top of it. Patches are changed every 72 hours and are for opioid-tolerant patients only, and exams test both of those facts.
Problem 6: MME
A patient takes meperidine (PO) 50 mg, 3 times daily. Using the equianalgesic table below, what is the total daily dose in morphine milligram equivalents (MME/day)?
| Opioid | PO (mg) | IV (mg) |
|---|
| morphine | 30 | 10 |
| hydromorphone | 7.5 | 1.5 |
| oxycodone | 20 | , |
| hydrocodone | 30 | , |
| codeine | 200 | , |
| meperidine | 300 | 75 |
| fentanyl | , | 0.1 (= 100 mcg) |
Round your answer to the nearest whole number.
Answer 15 MME/day
Solution- Find the right cell, drug AND route: 300 mg meperidine (PO) ≈ 30 mg morphine (PO).
- Daily dose: 50 mg/dose × 3 doses/day = 150 mg/day.
- Proportion: 300 mg / 30 mg = 150 mg / x → x = 150 mg/day × 30 mg ÷ 300 mg = 15 MME/day.
- Rounded as the question asks: 15 MME/day.
MME is just an equianalgesic conversion with 30 mg oral morphine as the anchor. 90 MME/day is the common review threshold in opioid safety guidance. MME factors are defined for ORAL opioids; a parenteral dose must first be converted to its oral equivalent, which is why the CDC table has no IV column.
Problem 7: Equianalgesic Conversion
A patient is receiving 450 mg/day of meperidine (PO). Using the equianalgesic table below, what is the equivalent daily dose of morphine (IV) in mg/day, before any cross-tolerance reduction?
| Opioid | PO (mg) | IV (mg) |
|---|
| morphine | 30 | 10 |
| hydromorphone | 7.5 | 1.5 |
| oxycodone | 20 | , |
| hydrocodone | 30 | , |
| codeine | 200 | , |
| meperidine | 300 | 75 |
| fentanyl | , | 0.1 (= 100 mcg) |
Round your answer to one decimal place.
Answer 15.0 mg/day
Solution- Pull the two relevant rows, drug AND route: meperidine (PO) = 300 mg ≈ morphine (IV) = 10 mg.
- Set up the proportion: 300 mg / 10 mg = 450 mg / x.
- x = 450 × 10 ÷ 300 = 15 mg/day = 15 mg/day of morphine (IV).
- Rounded as the question asks: 15.0 mg/day.
In practice the calculated dose is reduced by 25 to 50% for incomplete cross-tolerance, exam questions specify whether they want the raw conversion or the reduced dose. Meperidine bonus fact: normeperidine accumulation (seizure risk) makes it inappropriate for chronic pain, which exams like to test.
Problem 8: Fentanyl Patch
A patient's opioid regimen totals 165 mg/day of oral morphine equivalents. Using the conversion table below, which fentanyl patch strength (mcg/hr) is appropriate? This table comes from the product labeling and already builds in the conservative conversion factor, so no further cross-tolerance reduction is applied.
| Oral morphine (mg/day) | Fentanyl patch (mcg/hr) |
|---|
| 60 to 134 | 25 |
| 135 to 224 | 50 |
| 225 to 314 | 75 |
| 315 to 404 | 100 |
Round your answer to the nearest whole number.
Answer 50 mcg/hr
Solution- Find the range containing 165 mg/day → 135 to 224 mg/day.
- That row corresponds to the 50 mcg/hr patch.
- Rounded as the question asks: 50 mcg/hr.
Patch selection is a table LOOKUP rather than a proportion, so never interpolate between rows. The Duragesic table is deliberately conservative, so you do NOT subtract a further 25 to 50% on top of it. Patches are changed every 72 hours and are for opioid-tolerant patients only, and exams test both of those facts.
Problem 9: MME
A patient takes hydromorphone (PO) 2 mg, 4 times daily. Using the equianalgesic table below, what is the total daily dose in morphine milligram equivalents (MME/day)?
| Opioid | PO (mg) | IV (mg) |
|---|
| morphine | 30 | 10 |
| hydromorphone | 7.5 | 1.5 |
| oxycodone | 20 | , |
| hydrocodone | 30 | , |
| codeine | 200 | , |
| meperidine | 300 | 75 |
| fentanyl | , | 0.1 (= 100 mcg) |
Round your answer to the nearest whole number.
Answer 32 MME/day
Solution- Find the right cell, drug AND route: 7.5 mg hydromorphone (PO) ≈ 30 mg morphine (PO).
- Daily dose: 2 mg/dose × 4 doses/day = 8 mg/day.
- Proportion: 7.5 mg / 30 mg = 8 mg / x → x = 8 mg/day × 30 mg ÷ 7.5 mg = 32 MME/day.
- Rounded as the question asks: 32 MME/day.
MME is just an equianalgesic conversion with 30 mg oral morphine as the anchor. 90 MME/day is the common review threshold in opioid safety guidance. MME factors are defined for ORAL opioids; a parenteral dose must first be converted to its oral equivalent, which is why the CDC table has no IV column.
Problem 10: Equianalgesic Conversion
A patient is receiving 187.5 mg/day of meperidine (IV). Using the equianalgesic table below, what is the equivalent daily dose of fentanyl (IV) in mcg/day, before any cross-tolerance reduction?
| Opioid | PO (mg) | IV (mg) |
|---|
| morphine | 30 | 10 |
| hydromorphone | 7.5 | 1.5 |
| oxycodone | 20 | , |
| hydrocodone | 30 | , |
| codeine | 200 | , |
| meperidine | 300 | 75 |
| fentanyl | , | 0.1 (= 100 mcg) |
Round your answer to the nearest whole number.
Answer 250 mcg/day
Solution- Pull the two relevant rows, drug AND route: meperidine (IV) = 75 mg ≈ fentanyl (IV) = 0.1 mg.
- Set up the proportion: 75 mg / 0.1 mg = 187.5 mg / x.
- x = 187.5 × 0.1 ÷ 75 = 0.25 mg/day = 250 mcg/day of fentanyl (IV).
- Rounded as the question asks: 250 mcg/day.
In practice the calculated dose is reduced by 25 to 50% for incomplete cross-tolerance, exam questions specify whether they want the raw conversion or the reduced dose. Meperidine bonus fact: normeperidine accumulation (seizure risk) makes it inappropriate for chronic pain, which exams like to test.