Management of Cancer Pain When High-Dose Morphine is Inadequate

Opioid Rotation Strategy

For cancer patients with inadequate pain control on high-dose morphine, the National Comprehensive Cancer Network recommends opioid rotation to an alternative strong opioid such as hydromorphone, oxycodone, or fentanyl to improve pain control 1, 2
Calculate the total 24-hour morphine dose and determine the equianalgesic dose of the new opioid using conversion tables, then reduce the calculated equianalgesic dose by 25-50% to account for incomplete cross-tolerance 3, 1

The American Society of Clinical Oncology suggests hydromorphone as an alternative opioid, with a potency ratio to oral morphine of 7.5:1, and a calculated equianalgesic dose of ~67 mg/day oral hydromorphone 1
The European Society for Medical Oncology recommends oxycodone as an alternative opioid, with a potency ratio to oral morphine of 1.5-2:1, and a calculated equianalgesic dose of ~250-333 mg/day oral oxycodone 1
Methadone is also recommended, but its use should be initiated only by physicians experienced with its use due to complex pharmacokinetics, and requires careful monitoring due to long half-life and risk of accumulation 2, 1, 3

The National Comprehensive Cancer Network suggests adding anticonvulsants, such as gabapentin or pregabalin, for neuropathic pain components, and antidepressants, such as nortriptyline, duloxetine, or venlafaxine, for neuropathic pain components 4, 2
Spinal analgesia, nerve blocks, or neurosurgical interventions may be considered for selected patients with refractory pain, and subanesthetic doses of ketamine may be used for intractable pain 1, 2, 5

The American Society of Clinical Oncology recommends using buprenorphine in patients with severe renal impairment 1
The National Comprehensive Cancer Network suggests providing rapid-onset opioids, such as transmucosal fentanyl, for breakthrough pain in addition to around-the-clock dosing 6

The European Society for Medical Oncology warns against inadequate dose reduction when rotating opioids, which can lead to overdosing, and overlooking adjuvant therapies for specific pain types 3, 2, 4
The National Comprehensive Cancer Network advises against ignoring non-pharmacological options, such as radiation therapy or interventional procedures, that may reduce opioid requirements 5