What's the next step for a patient with inadequate pain relief from a fentanyl (transdermal opioid) patch and Roxicodone (oxycodone)?

Opioid Rotation to an Alternative Long-Acting Opioid

When fentanyl patch and oxycodone (Roxicodone) fail to provide adequate pain control, the next step is opioid rotation to a different long-acting opioid such as morphine extended-release, hydromorphone extended-release, or methadone, with a 25-50% dose reduction to account for incomplete cross-tolerance. 1

Immediate Management Strategy

Calculate Total 24-Hour Opioid Requirement

• Add together all scheduled and breakthrough opioid doses taken in the previous 24 hours to determine the total daily opioid consumption 1
• Convert this total to oral morphine equivalents using standard equianalgesic conversion tables 1, 2
• This calculation forms the basis for selecting the new opioid and its starting dose 1

Apply Dose Reduction for Opioid Rotation

• Reduce the calculated equianalgesic dose by 25-50% when switching to a different opioid to account for incomplete cross-tolerance between opioids 1
• This reduction is critical because patients may be more sensitive to a new opioid than predicted by conversion tables alone 1, 2
• If pain was poorly controlled on the previous regimen, consider a smaller reduction (25%) rather than 50% 1

Selecting the Next Opioid

First-Line Alternatives for Opioid Rotation

• Morphine extended-release is generally considered the standard preferred opioid and has the most evidence for long-term effectiveness in chronic pain 1, 3
• Hydromorphone extended-release has properties similar to morphine and is available in multiple formulations 1
• Methadone can be considered for resistant pain but requires specialist consultation due to its long and variable half-life 1

Critical Considerations for Opioid Selection

• Avoid morphine, hydromorphone, and codeine in patients with renal insufficiency due to accumulation of neurotoxic metabolites 1
• Short half-life opioid agonists (morphine, hydromorphone, oxycodone) are preferred over long half-life analgesics (methadone, levorphanol) because they can be more easily titrated 1
• Mixed agonist-antagonists should NOT be used as they have limited usefulness and can precipitate withdrawal in opioid-dependent patients 1

Titration Protocol

Rapid Dose Escalation for Severe Pain

• Titrate liberally and rapidly to analgesic effect during the first 24-48 hours when pain is severe or inadequately controlled 1, 4
• The rapidity of dose escalation should be related to the severity of symptoms 1
• Increase both around-the-clock and breakthrough doses based on total opioid consumption 1

Breakthrough Medication Requirements

• Provide rescue doses of short-acting opioids at 10-20% of the 24-hour oral dose for breakthrough pain 1
• Use the same opioid for short-acting and extended-release forms when possible 1
• Ongoing need for repeated rescue doses indicates the need to increase the baseline long-acting opioid dose 1

Adjuvant Analgesics to Consider

For Neuropathic Pain Component

• Trial of antidepressants: Start nortriptyline 10-150 mg/day, desipramine 10-150 mg/day, venlafaxine 37.5-225 mg/day, or duloxetine 30-60 mg/day 1
• Trial of anticonvulsants: Start gabapentin 100-1200 mg three times daily or pregabalin 100-600 mg/day divided in 2-3 doses 1
• Increase doses every 3-5 days if tolerated, or lengthen the interval up to 14 days 1

For Inflammatory Pain Component

• Trial of NSAIDs or glucocorticoids if pain is associated with inflammation 1
• Consider topical agents such as lidocaine patches for localized peripheral neuropathic pain 1

Common Pitfalls to Avoid

Conversion Errors

• Never use conversion tables in reverse (i.e., do not use fentanyl-to-morphine tables to convert from fentanyl to another opioid) as this will overestimate the new opioid dose and may result in fatal overdosage 2
• The conversion to fentanyl transdermal system is intentionally conservative; reversing these calculations leads to dangerous overestimation 2

Inadequate Monitoring

• Monitor closely for at least 24-48 hours after opioid rotation for both inadequate pain control and opioid-related adverse effects 1, 4
• Be prepared to adjust doses more frequently during the conversion period based on clinical response 4
• Steady state is achieved in approximately 5 half-lives of the new opioid 1

When to Refer to Pain Specialist

Indications for Specialist Consultation

• Refer for resistant pain that fails to respond to first-line opioid rotation and adjuvant analgesics 1
• Consider referral for interventional strategies when pharmacologic management is inadequate 1
• Methadone initiation typically requires pain specialist involvement due to complex pharmacokinetics 1