People who experience moderate cancer pain gain significantly greater pain relief when treated with low-dose morphine compared to weak opioids, a study published in the Journal of Clinical Oncology this month concludes.
The purpose of the study was to tease out whether the World Health Organization (WHO) guidelines on managing cancer pain – a three-step analgesic ladder – can be more definitive in guiding the treatment of moderate cancer pain. There are no conclusive data on whether moderate cancer pain should be treated with a step II weak opioid or a step III strong opioid.
In a multicenter, open-label, randomized controlled trial, 240 adults with moderate cancer pain received either a step II weak opioid, like codeine phosphate, or low-dose step III strong opioid, like morphine, for 28 days. They rated their pain intensity on a numerical pain scale.
The primary outcome was the number of study participants who experienced a 20% reduction in pain intensity.
Slightly more than 88% of those taking low-dose morphine achieved a 20% reduction in pain intensity, while just under 58% of those taking weak opioids achieved that same outcome.
The Italian researchers found that the participants on the low-dose morphine group experienced a 20% pain reduction as early as the first week of the 28 day treatment.
“Clinically meaningful (≥ 30%) and highly meaningful (≥ 50%) pain reduction from baseline was significantly higher in the low-dose morphine group (P < .001),” the authors wrote.
Many in the group taking weak opioids had to change to low-dose morphine because they were not achieving adequate pain relief.
The authors did note that the overall condition of the participants in the low-dose morphine group “was better” as defined by the Edmonton Symptom Assessment System. They also noted that adverse effects were about the same in both groups.
These findings from the study, Randomized Trial of Low-Dose Morphine Versus Weak Opioids in Moderate Cancer Pain, may help oncologists and pain management specialist re-assess the Pain Ladder when managing moderate cancer pain by skipping step II and starting treatment with low dose morphine.