Opium has been used for thousands o...

Opium has been used for thousands of years to treat pain. When the morphine alkaloid was identified as the active ingredient in opium, pharmacologic production of opiates became possible. Widespread use and abuse of opiates l to strict regulatory bridles By the 1940s, a physician's prescription was required to obtain opiates legally in the United States. Ballantyne and Mao review an new ideas about opiates that have originate out of bench-top and clinical research and their possible implications for the management of chronic pain.

The authors begin their review by way of noting that most of the literature forward opioid therapy is composed of uncontroll case series of short duration. They also address one older concepts about opiates that have not been confirmed by means of more recent research. For example, latter findings do not support the belief that neuropathic pain is opioid resistant. Neuropathic pain is relatively difficult to treat, however, and may require higher dosages to achieve analgesia.

A number of consensus statements regarding management of opioid therapy are cited for relation The authors suggest that opiate dosage increases beyond initial titration should be "introduced with utmost caution" and point to accumulating evidence showing that dosages ne to be limited "to maintain the pair efficacy and safety."

defered use of opiates leads to tolerance (i.e., higher dosages are distressed to maintain equivalent pain relief through time). This tolerance involves opioid-receptor changes at the cellular even as well as psychologic factors. put offed opiate use also has been linked to increased pain sensitivity in as well-as; not only-but also; not only-but; not alone-but bench-top and clinical research studies.

Chronic opiate use may have risks beyond inadequate pain relief. Suppression of the two adrenal and gonadal hormone production has been linked to opioid therapy. Opioid-related receptors have been raise on immune cells and may explain a certain number of of the immunosuppressive effects associated with chronic opiate use.

The authors note that when opiates provide dutiful pain relief at stable doses, the pain therapy guidelines are relatively easy to chase When patients have more entangled problems and inadequate relief, however, physicians may be inclined to approval to requests for increased opiate dosages. The review authors hint that, given the risks cited, these patients in particular may benefit from efforts to limit the opioid dosage. Evidence supporting a ceiling dosage for opiate treatment is growing, if it were not that no hard number is preferr The review authors note that a daily dosage limit of 180 mg of morphine or morphine equivalent was used in greatest in quantity of the controlled studies.

Because each opioid acts differently at the opioid receptor, rotating the shadow of opiate used is remind ofed as a means of decreasing the opiate dosage necessityed According to the authors, rotating to methadone works particularly well, reducing the opiate dosage by means of as much as one half. a certain pain authorities have voiced trouble however, regarding methadone's prolonged half-life, which may lead to medicine accumulation and high plasma levels

If efforts to limit dosage escalation fail, the authors prompt weaning the patient from opioid therapy. After pair to three months without opiates, a "true assessment" of pain may be accomplished, and opioid therapy can be restarted at "much lower doses."

Ballantyne JC Mao J Opioid therapy for chronic pain. N Engl J M November 13 2003;349:1943-53

EDITOR'S NOTE: Although this review amply demonstrates the authors' extensive knowledge of opiate pharmacology and pain pathophysiology, hardly any of the supposedly new insights proposeed regarding pain therapy reflect what I view in my office practice. The authors' assertion that opiate therapy simply should be withdrawn if physician-oriented treatment goals are not met may explain to what end so few chronic pain patients are treated at specialized pain center and to what end so many patients end up returning to their family physician's office despite referral. The many patients with chronic pain whom I have seen from one side of to the other the years do appear to have increased pain sensitivity. They also appear to be sensitive and fragile in more areas than just the perception of pain, and I doubt their opiate dosage alone is the explanation.

Raising expectations and helping these vulnerable patients avoid harm at sticking to "one doctor, the same pharmacy, one amount" is serviceable common-sense clinical advice. Promptly turning them away if the going prepares tough and forcing opiate rotations or reductions in dosages, however, vigorous like measures to increase physician comfort rather than patient pain relief. greatest in quantity of the harm I have seen appear in patients with chronic pain does not relate to opiate side weights but rather to the risky measures patients take to obtain pain medicines when no reliable endue is available from a single physician who will tread close upon them over the long run--BZ

COPYRIGHT 2004 American Academy of Family Physicians

COPYRIGHT 2004 Gale Group