Opioid Switch Dosing in Chronic Cancer Pain: A Prospective Longitudinal Study.

Area of Science:

• Oncology
• Palliative Care
• Pharmacology

Background:

• Opioid switching is a frequent practice in managing cancer pain.
• Existing opioid conversion tables have recognized limitations.
• Current guidelines often recommend dose reduction post-opioid switch, contrasting with observed clinical practice.

Purpose of the Study:

• To determine the actual opioid conversion factor following opioid switching in advanced cancer patients.
• To investigate if pain intensity and adverse effect profiles differ among patients switched to various opioids.

Main Methods:

• A multicenter prospective longitudinal study was conducted in Australia.
• Participants included individuals with advanced cancer.
• Clinical data, including opioid use, pain scores, and adverse effects, were collected twice, seven days apart.

Main Results:

• Opioid switching resulted in a median increase in daily oral morphine equivalent dose from 90 mg to 150 mg.
• Average pain scores decreased significantly post-switch (from 5.1 to 3.8).
• Adverse effects were also reduced; hydromorphone doses increased 2.5 times the initial conversion factor.

Conclusions:

• Opioid switching, particularly to hydromorphone, commonly leads to dose escalation.
• Higher pre-switch opioid doses may necessitate higher conversion ratios.
• Post-switch dose reduction may be inappropriate and risks undertreatment.