APS Press Room
News Highlights from The Journal of Pain • January 2006
The Peer Review Journal of the American Pain Society
| For immediate release | Contact: Chuck Weber (847) 705-1802 |
DO OPIOID PAIN MEDICATIONS INCREASE PAIN SENSITIVITY?
Article Title: Opioid Tolerance and Hyperalgesia in Chronic Pain Patients After One Month of Oral Morphine Therapy
Authors: Larry F. Chu, David J. Clark and Martin S. Angst, Stanford University School of Medicine
GLENVIEW, Ill., Jan. 27, 2006 – There are no prospective studies documenting the development of opioid tolerance in chronic pain patients. In this study, Stanford researchers sought preliminary prospective evidence for the development of tolerance or hyperalgesia from sustained-acting oral opioids. Six patients with chronic low back pain were assessed before and after one month of oral morphine therapy. The cold pressor and experimental heat pain tests were used to measure pain sensitivity. Cold pressor test subjects became hyperalgesic and tolerant after one month of morphine treatment, while the heat pain patients showed no hyperalgesia and drug tolerance could not be evaluated.
The authors believe the study validates their prospective methodology for larger trials in the future. In addition, they determined from their evidence that opioid tolerance and opioid-induced hyperalgesia might limit the clinical utility of opioids in controlling chronic pain.
IS YOUR PAIN LEVEL A FIVE OR A SIX?
Article title: Asking the Community About Cutpoints Used to Describe Mild, Moderate and Severe Pain
Authors: Guadalupe R. Palos, Tito R.Mendoza, Gary M. Mobley, Scott B. Cantor and Charles Cleeland, University of Texas M.D. Anderson Cancer Center
Clinical practice guidelines recommend that adults use a numeric scale (0 to 10) to rate the severity of their pain. However, in most instances, patients and clinicians use the terms mild, moderate and severe to classify pain. This study assessed how well numeric scales correlate with the tri-level classification to identify numeric boundaries used by 287 adults to describe mild, moderate and severe pain. Ranges reported for each pain level were 1.3 to 3.6 for mild pain, 4.3 to 6.5 for moderate pain and 7.5 to 9.8 for severe pain. These findings support using numeric scales more extensively in clinical practice. The authors concluded that having standard categories to describe pain severity might increase clinician confidence in using numeric scales to make treatment decisions.
DOES PAIN AFFECT ATTENTION?
Article title: Pain and Attention: Attentional Disruption or Distraction?
Authors: Dieuwke S. Veldhuijzen, J. Leon Kenemans, C. Martine de Bruin, Berend Oliver and Edmund R. Volkerts, Hemholtz Research Institute, University of Utrecht, The Netherlands
For this study, the authors hypothesized that pain would negatively influence task performance under different load manipulations. Some studies have shown allocating attention to a cognitive task can modulate pain perception, and difficult tasks are more successful in altering pain perception. Conversely, there is research showing that when the task difficulty is high, patients in moderate-to-severe pain performed worse than patients with low or no pain.
Two experiments were performed using high and low task loads combined with a painfully cold or neutral cold pressor test. The researchers found that pain processing interferes with highly demanding attentional task performance as a result of difficulties in allocating attention. Clinically, this is relevant because patients might be able to distract attention from their pain by performing a highly demanding task.