Medication Risk
High opioid loads drive avoidable harm on injury claims. This opioid oMEDD calculator adds every regular opioid, brand or generic, and totals the oral morphine equivalent daily dose against published risk thresholds.
Opioid oMEDD calculator
Search by generic name or by brand name from Australia, the United States, Canada or the United Kingdom, for example Endone, Percocet, Oramorph, Hydromorph Contin or tapentadol. Enter the dose and frequency, and the calculator converts each medicine to milligrams of oral morphine per day and keeps a running total.
Recognises brand names from AU US CA UK including Endone, OxyContin, Targin, Norco, Dilaudid, Nucynta, Supeudol, Zomorph, Butrans and Durogesic.
Medication list
The calculations run entirely in your browser. No medication, dose or patient information you enter is stored or transmitted; the site records only an anonymous count of how often the calculator is used. It supports education and clinical review; it does not replace clinical judgement, the approved product information, or individual patient assessment.
What does the total oMEDD mean?
Higher total opioid exposure is consistently associated with a higher risk of harm, including overdose and death, without evidence of proportionate added benefit in chronic non-cancer pain. Australian schemes and prescribing guidance use the total as a review trigger, so it is worth checking any claim where multiple opioids or long-term therapy appear on the pharmacy record against these opioid risk thresholds.
| Total oMEDD | Interpretation | Suggested action |
|---|---|---|
| Under 50 mg/day | Lower-risk range | Routine monitoring. Confirm ongoing benefit and function. |
| 50-99 mg/day | Increased risk of opioid-related harm | Formal review of benefit versus harm. Consider taper planning and non-opioid strategies. |
| 100 mg/day or more | High risk, associated with substantially increased risk of overdose and death | Structured medication review strongly recommended. Consider specialist input, staged supply, naloxone and a taper plan. |
These thresholds reflect Australian guidance: RACGP prescribing guidance and SIRA NSW clinical frameworks use 50 and 100 mg oMEDD as review triggers, while the US CDC 2022 guideline applies caution points at 50 and 90 morphine milligram equivalents per day.
Which opioid conversion factors does the calculator use?
Each daily dose is multiplied by its published conversion factor to express it as milligrams of oral morphine per day, then summed across all regular opioids. The primary standard is the ANZCA FPM opioid calculator table, PS01(PM) Appendix 2, which is the reference set of opioid conversion factors in Australian clinical and medicolegal practice. Where a medicine does not appear in the FPM table, the factor comes from the US CDC 2022 opioid prescribing guideline or the UK Faculty of Pain Medicine Opioids Aware resource, and the calculator identifies the source beside every factor. The eviQ opioid conversion calculator is the comparable Australian oncology and palliative care implementation.
| Opioid (route) | Unit | Factor | Source |
|---|---|---|---|
| Morphine (oral) | mg/day | x 1 | FPM |
| Oxycodone (oral), including oxycodone/naloxone | mg/day | x 1.5 | FPM |
| Hydromorphone (oral) | mg/day | x 5 | FPM |
| Codeine (oral) | mg/day | x 0.13 | FPM |
| Tramadol (oral) | mg/day | x 0.2 | FPM |
| Tapentadol (oral) | mg/day | x 0.3 | FPM |
| Dextropropoxyphene (oral) | mg/day | x 0.1 | FPM |
| Hydrocodone (oral) | mg/day | x 1 | CDC |
| Oxymorphone (oral) | mg/day | x 3 | CDC |
| Dihydrocodeine (oral) | mg/day | x 0.1 | UK FPM |
| Pethidine / meperidine (oral) | mg/day | x 0.1 | CDC |
| Buprenorphine (sublingual, pain indication) | mg/day | x 40 | FPM |
| Buprenorphine (transdermal patch) | mcg/hr | x 2 | FPM |
| Fentanyl (transdermal patch) | mcg/hr | x 3 | FPM |
Patches are entered as patch strength, so the fentanyl patch conversion is 3 mg oMEDD per mcg/hr and the buprenorphine patch conversion is 2 mg oMEDD per mcg/hr. Published factors vary between jurisdictions: tapentadol is 0.3 in the FPM table and 0.4 in the CDC file, and fentanyl patches are x 3 per mcg/hr in the FPM table against x 2.4 in CDC materials, which is why different calculators can give different answers for the same regimen. For dihydrocodeine, the UK Faculty of Pain Medicine equivalence (100 mg is about 10 mg of oral morphine) is used because the medicine is predominantly prescribed in the UK.
Why are methadone and transmucosal fentanyl excluded?
Some opioids cannot be reduced to a single reliable factor, and pretending otherwise produces totals that look precise but are clinically wrong. The calculator recognises these medicines, lists them with a flag so the medication list stays complete, and leaves them out of the total. When a flagged medicine appears on a claim, the true opioid exposure is higher than the displayed total and specialist review is warranted.
How should PRN doses and combination products be entered?
For as-needed doses, enter the average actual daily use rather than the maximum prescribed. A worker prescribed oxycodone 5 mg up to four times daily who typically uses two doses is entered as 5 mg at two doses per day. Dispense records and real-time prescription monitoring data give a far better picture of actual use than the directions on the script.
For combination products, only the opioid component counts. The calculator maps combination brands to their opioid, so Percocet and Endocet map to oxycodone, Panadeine Forte and co-codamol map to codeine, and Norco and Vicodin map to hydrocodone, and it prompts for the opioid component strength, for example 5 mg per tablet for Percocet 5/325.
Key Takeaways
- A total oMEDD of 50 mg per day or more should trigger a formal review of benefit versus harm.
- A total of 100 mg per day or more is associated with substantially increased risk of overdose and death.
- The calculator recognises Australian, US, Canadian and UK brand names and maps combination products to their opioid component.
- Methadone, transmucosal fentanyl and buprenorphine opioid agonist therapy are flagged but excluded from the total, so true exposure is higher when they appear.
- oMEDD measures total exposure for risk review and is not a dose conversion tool for opioid rotation.
Frequently Asked Questions
What is an oMEDD?
Oral morphine equivalent daily dose expresses all of a person's regular opioids as a single figure, the equivalent daily dose of oral morphine. It lets total opioid exposure be tracked and compared against published risk thresholds.
How should PRN doses be entered?
Use the average actual daily use, not the maximum prescribed. If oxycodone 5 mg is prescribed up to four times daily but the person typically uses two doses, enter 5 mg at two doses per day.
How are combination products like Percocet or co-codamol handled?
Only the opioid component counts. The calculator maps combination brands to their opioid and prompts you to enter the opioid component strength, for example 5 mg per tablet for Percocet 5/325.
Can the calculator be used to switch a patient between opioids?
No. Opioid rotation requires a dose reduction for incomplete cross tolerance, usually 25 to 50 per cent, plus individual clinical assessment and close monitoring. The calculator measures total exposure only.
Primary source: Faculty of Pain Medicine, Australian and New Zealand College of Anaesthetists (FPM ANZCA), PS01(PM) Appendix 2 opioid dose equivalence table, 2025.
