All calculations must be confirmed before use. The authors make no claims of the accuracy of the information contained herein; and these suggested doses are not a substitute for clinical judgement.

Please review the importance of correcting for incomplete cross-tolerance. Equianalagesic conversions should not be considered a simple straightforward calculation. Significant 'inter/intra' patient variability exists depending on the selected opiate, dosage level, and expected response

Incomplete cross-tolerance relates to tolerance to a currently administered opiate that does not extend completely to other opioids. This will tend to lower the required dose of the second opioid. This incomplete cross-tolerance exists between all of the opioids and the estimated difference between any two opiates could vary widely. This points out the inherent dangers of using an equianalgesic table and the importance of viewing the tabulated data as approximations. Many experts recommend - depending on age and prior side effects - reducing the dose of the new opiate by up to 33-50% to account for this incomplete cross-tolerance. (Example: a patient is receiving 200mg of oral morphine daily (chronic dosing), however, because of side effects a switch is made to oral hydromorphone 25-35mg daily (this represents a 33-50% reduction in dose compared to the calculated 50mg conversion dose produced via the equianalgesic calculator). This new regimen can then be re-titrated to patient response. In all cases, repeated comprehensive assessments of pain are necessary in order to successfully control the pain while minimizing side-effects.