What are the recommendations for initiating long-acting opiate (opioid) medication in addition to short-acting opiate (opioid) for cancer patients with moderate to severe pain?

When to Initiate Long-Acting Opioids in Cancer Pain

Long-acting opioids should be initiated once pain is adequately controlled with short-acting opioids and a stable 24-hour opioid requirement has been established, typically after titration over several days. 1

Initial Management: Start with Short-Acting Opioids

• Begin with short-acting oral morphine (5-15 mg) or equivalent for opioid-naïve patients with moderate to severe cancer pain. 1
• For severe pain requiring urgent relief, use parenteral short-acting opioids (IV or subcutaneous morphine 2-5 mg) with the oral-to-parenteral conversion ratio of 1:2 to 1:3. 1
• Titrate the short-acting opioid dose by assessing pain every 4 hours for oral administration or every 15 minutes for IV administration. 1

Establishing Baseline Opioid Requirements

• Provide "rescue" doses of short-acting opioids (10-20% of total 24-hour requirement) for breakthrough pain during the titration phase. 2
• If more than 4 breakthrough doses per day are needed, increase the baseline around-the-clock dosing rather than continuing with frequent rescue doses. 2
• Continue titration with short-acting opioids until pain is consistently controlled at mild or no pain levels for at least 24 hours. 1, 2

Transition to Long-Acting Formulations

Once the total 24-hour opioid requirement is stable and pain is adequately controlled, convert to a long-acting or extended-release formulation. 1, 2

Key Principles for Conversion:

• Calculate the total daily dose of short-acting opioid used over the previous 24 hours. 1
• Convert this total to an equianalgesic dose of the chosen long-acting formulation (morphine, oxycodone, hydromorphone, or transdermal fentanyl). 1
• Continue to provide short-acting opioids for breakthrough pain at 10-20% of the new total daily long-acting dose. 2

Special Considerations for Transdermal Fentanyl

Transdermal fentanyl is contraindicated during the initial titration phase and should only be used in opioid-tolerant patients with stable pain requirements. 1, 3

• Patients must be opioid-tolerant, defined as taking at least 60 mg oral morphine daily, 25 mcg/hour transdermal fentanyl, 30 mg oral oxycodone daily, or equianalgesic doses for one week or longer. 3
• Transdermal fentanyl is not indicated for rapid opioid titration or as-needed pain relief. 1, 3
• Reserve transdermal systems for patients unable to swallow, those with poor morphine tolerance, or compliance issues once pain is controlled. 1

Common Pitfalls to Avoid

• Never initiate long-acting opioids in opioid-naïve patients or during active pain titration - this increases risk of respiratory depression and overdose. 3
• Avoid using transdermal fentanyl for breakthrough pain or unstable pain syndromes. 1
• Do not skip the titration phase with short-acting opioids - attempting to estimate long-acting doses without establishing actual requirements leads to inadequate pain control or excessive sedation. 1
• Failing to provide adequate breakthrough medication (short-acting opioids) even after starting long-acting formulations is a common error. 2

Monitoring After Transition

• Reassess pain intensity, sedation level, and adverse effects regularly after converting to long-acting opioids. 1
• Continue to adjust the long-acting dose based on breakthrough medication requirements - if consistently needing more than 4 rescue doses daily, increase the baseline long-acting dose. 2
• Implement prophylactic bowel regimens when initiating any opioid therapy, as constipation is nearly universal and requires preventive management. 1