Opiate use in nonmalignant pain: Not a simple dichotomy

The use of opiates in chronic nonmalignant pain has its share of proponents and opponents among urologists who specialize in chronic pelvic pain.

"I'm antinarcotics, and there are a number of reasons for it in this set of patients, primarily because, in my experience, patients have poor quality of life once they start the narcotic spiral," longtime chronic prostatitis/chronic pelvic pain researcher J. Curtis Nickel, MD, professor of urology at Queen's University in Kingston, Ontario, Canada, told participants at the Chronic Pelvic Pain/Chronic Prostatitis Workshop.

He cited sexual hyperalgesia and sexual dysfunction in both men and women as two of those reasons.

For perspective on the debate, Urology Times spoke with pain expert and researcher Daniel Carr, MD, about the evidence base for the use of opiates in nonmalignant pain conditions such as these. Dr. Carr, Saltonstall professor of pain research at New England Medical Center, Boston, treats many patients with pelvic pain. His meta-analysis of the efficacy and safety of opioid agonists in nonmalignant neuropathic pain was published in JAMA last year (2005; 293:3043-52).

He cautioned against oversimplifying the clinical issue of opioids into a dichotomy.

"At the top of the evidence list is the mathematical pooling or meta-analysis of results from randomized controlled trials," Dr. Carr said. "For years, many clinicians and scientists, including those from our group at Tufts-New England Medical Center, have viewed the pain of IC, which often is triggered by diverse insults and continues in the absence of uniformly identifiable pathophysiology, as having a strong or even predominant neuropathic component. Although the evidence is still incomplete, meta-analysis of the best available evidence indicates quite clearly that opioids are efficacious for neuropathic pain."

In addition, Dr. Carr pointed to a recent randomized controlled trial that found that gabapentin (Neurontin) and morphine combined achieved better analgesia at lower doses of each drug than either as a single agent (N Engl J Med 2005; 352:1324-34).

"So, from my point of view, the optimal approach is to decide with each patient what works best and not to maintain any component of a medical regimen unless it is of ongoing benefit," he said.