Opioid Conversion and Management

Conversion Guidelines

When converting from oral morphine to intravenous morphine, the potency ratio is 3:1 (oral:IV), meaning the intravenous dose is approximately one-third of the oral dose, as recommended by the National Comprehensive Cancer Network 1, 2
The American Society of Clinical Oncology and the National Comprehensive Cancer Network suggest that morphine is generally considered the standard first-line opioid for moderate to severe pain 1, 3

For patients with severe pain requiring urgent relief, the use of parenteral opioids, typically administered intravenously or subcutaneously, is recommended by the National Comprehensive Cancer Network 1, 2
The initial recommended dose for patients with no prior exposure to opioids is 2 to 5 mg of morphine sulfate intravenously or its equivalent, as suggested by the Journal of the National Comprehensive Cancer Network 3
Assessment of efficacy and side effects should be performed every 15 minutes for intravenously administered opioids, according to the Journal of the National Comprehensive Cancer Network 4

In patients with renal insufficiency, all opioids should be used with caution and at reduced doses, as recommended by the European Society for Medical Oncology and the National Comprehensive Cancer Network 1, 5
Fentanyl and buprenorphine via transdermal or intravenous routes are the safest opioids for patients with chronic kidney disease stages 4 or 5, according to the European Society for Medical Oncology and the National Comprehensive Cancer Network 1, 5
Morphine, hydromorphone, hydrocodone, oxymorphone, and codeine should be used with caution in patients with fluctuating renal function due to the possible accumulation of metabolites eliminated by the kidneys that can cause neurotoxicity, as suggested by the National Comprehensive Cancer Network 3

A preventive regimen for constipation is recommended when initiating opioid therapy, as suggested by the Journal of the National Comprehensive Cancer Network 4