The use of narcotic drugs such as opioids has been up and down over the years. Concern about dependence and addiction led to tighter controls on their long-term use. But an increase in support for their use in the late 1990s brought the debate back out into the open. As a result, there was a rash of studies done using opioids for chronic pain problems.
In this report, the issues are reviewed and the results of recent randomized-controlled trials (RCTs) are presented. Most of the studies done were with arthritic patients and people with neuropathic (nerve-related) pain. There had been some belief that opioids couldn’t treat neuropathic conditions effectively.
The studies all showed that opioids do, indeed, control pain in all conditions tested. But it should be noted that the studies were short-term and the doses used were moderate.
Although pain was well-controlled, this did not always translate into improved function. Function was defined differently in various studies but included motion, strength, activities, and work. Again, the assessments were all short-term in length. And some studies found that weak opioids worked well to improve function. Strong opioids worked better for reducing pain.
Given a choice, about half the patients discontinued opioid therapy. There were several different reasons for this decision. Some were concerned about adverse effects. Others obtained the desired pain relief. Those who continued using opioids for chronic pain had to increase the dose somewhat but did not experience addiction.
The authors report many problems with the studies themselves. Poor study design, bias in choosing patients, and trouble defining a positive result were just a few of the difficulties. Other factors may have also come into play. For example, the support of health care providers could not be separated from the effect of the drug.
There is a need for long-term studies with opioid therapy. But the problem with randomized-controlled trials is that some people don’t get the treatment they need. So it’s not practical to try completing this type of study for the number of years needed to answer the questions about long-term benefit of opioids for chronic pain conditions.
For now it’s clear that opioid therapy works well for short-term relief of pain. The long-term benefits are less obvious. More research is needed to understand the basic mechanisms of this drug. Identifying which patients can benefit most from this treatment is another answer needed from study of this potent medication.