Question 1

Why do equianalgesic conversion tables vary between sources?

Accepted Answer

Different organisations publish slightly different conversion ratios due to variations in the primary evidence interpreted. The calculator uses a consensus-based set of ratios aligned with the EAPC and Australian Therapeutic Guidelines. Clinical judgement is required — start with 50–75% of the calculated dose when rotating, due to incomplete cross-tolerance.

Question 2

Does MEDD account for incomplete cross-tolerance?

Accepted Answer

No — the calculator provides theoretical equianalgesic doses. Due to incomplete cross-tolerance between opioids, reduce the calculated dose by 25–50% when initiating a new opioid and titrate to effect. This is particularly important when switching from high-dose opioids.

Question 3

What MEDD threshold warrants concern?

Accepted Answer

A MEDD ≥100 mg/day is associated with increased risk of opioid-related adverse events. ≥200 mg/day warrants Naloxone co-prescribing (in many guidelines). ≥400 mg/day requires specialist review and consideration of opioid rotation, interventional pain techniques, or de-prescribing strategies.

Question 4

How should breakthrough (PRN) opioids be included in the MEDD?

Accepted Answer

Include the actual average daily consumption of breakthrough medication over the preceding 3–7 days, not the prescribed maximum. Breakthrough doses typically account for 10–20% of total daily opioid requirement. When calculating MEDD for a planned rotation, use the total daily dose including actual PRN usage.