Iíve already indicated that the use of opioids is controversial in essentially all settings. Debate still persists about medicating terminal patients, so you can imagine how heated the discussion becomes for treating chronic pain, a setting in which there is no end in sight and where complaints often appear to be out of proportion to accompanying physical signs or x-ray findings. Regrettably, most of todayís cure-oriented physicians still do not understand chronic pain. Since it has only been recently that, stimulated by hordes of frustrated patients, a few physicians have even developed the courage to ask questions about chronic pain and opioids, it is not surprising that answers are still elusive.
This question is actually probably best regarded as two related questions: (1) are opioids effective in relieving chronic pain, and (2) if so, when (if ever) is their use appropriate? The bad news is that the ultimate answer to whether opioids are effective in the long term will only be answered with certainty with controlled clinical trials which have not even yet been proposed. Since it would be unethical to allow patients to suffer while awaiting this data, we need to be asking what is known that will help guide todayís treatment safely?
The good news is that there has been increasing experience with using opioids to treat chronic pain due to a variety of causes. While still not as reliable as a controlled trial, data from this experience can be cautiously applied to many of todayís patients with chronic pain. It appears that opioids effectively reduce pain over long intervals in a proportion of patients with chronic pain without intolerable side effects or problems with addiction. One key point here is that as long as the source of pain persists, pain can often be reduced but rarely if ever is it eliminated. Thus, if treatment is to even have a chance at success, patients must maintain realistic expectations, such as a 50% reduction in pain severity. Another key point relates to side effects: in fact, most patients will experience side effects when opioids are first started or their dose is changed, but when medications are started in low doses, are only gradually increased, and with reliance on long-acting formulations side effects can usually be resolved or minimized. Most patients will continue to experience low level side effects as long as opioid therapy is ongoing, but this may represent a reasonable tradeoff if pain is severe. While opioids may produce dangerous respiratory depression when used erratically, this almost never occurs with carefully supervised use. Nausea, sedation and itch are common at first, but usually resolve over time. Constipation is an ongoing difficulty that can and must be prevented with activity, diet and regular gentle laxative use. Because fatigue so commonly accompanies chronic pain, most patients cannot tolerate high doses of opioids, and thus must be satisfied with partial relief. In other words, while opioids are helpful in some cases, they donít eliminate chronic pain: patients continue to have ongoing, but lower grade symptoms, with some good and some bad days. These drugs are not a panacea, but simply represent one of the many tools at our disposal to help make chronic pain more bearable. Moreover, opioids are usually not a first line treatment, and work best when integrated with other drug treatments like antidepressants, anti-inflammatories, muscle relaxants and anticonvulsants, as well as with non-drug therapies like physical therapy, distraction and relaxation training.