Long-term use of opioids for complex chronic pain
ABSTRACT Increased opioid prescribing for back pain and other chronic musculoskeletal pain conditions has been accompanied by dramatic increases in prescription-opioid addiction and fatal overdose. Opioid-related risks appear to increase with dose. Although short-term randomised trials of opioids for chronic pain have found modest analgesic benefits (a one-third reduction in pain intensity on average), the long-term safety and effectiveness of opioids for chronic musculoskeletal pain remains unknown. Given the lack of large, long-term randomised trials, recent epidemiologic data suggest the need for caution when considering long-term use of opioids to manage chronic musculoskeletal pain, particularly at higher dosage levels. Principles for achieving more selective and cautious use of opioids for chronic musculoskeletal pain are proposed.
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- "The first line drugs used to treat neuropathic pain, such as pregabalin or gabapentin, only produce partial pain relief in a subset of patients   . Opioid analgesics are ineffective against neuropathic pain in the majority of patients and are often associated with side effects including constipation, tolerance and drug abuse  . Traditional Chinese medicines (TCM) are widely used for management of various clinical pain conditions in China and may harbour a rich source of potential drug candidates, which Western drug companies are turning to with ever increasing urgency . "
ABSTRACT: Background and aims We have previously reported that systemic administration of sinomenine produced antinociception in various experimental pain conditions in rodents, particularly in models of neuropathic pain. In the present study we assessed the effects of repeated administration of sinomenine in two rodent models of neuropathic pain in order to study the development of tolerance. Methods The analgesic effect of sinomenine was tested in female Sprague-Dawley rats that exhibited mechanical and cold hypersensitivity following ischaemic injury to the spinal cord and in male C57/BL6 mice that developed mechanical hypersensitivity after ischaemic injury to the sciatic nerve. Briefly, the animals were anaesthetized and injected i.v. with the photosensitizing dye erythrosine B. Vertebral segments T12 to T13 in rats or the sciatic nerve in mice were exposed and irradiated under an argon ion laser for 10 min or 45 s, respectively. In rats, mechanical hypersensitivity to pressure with von Frey hairs, the response to brushing and decreasing cold temperature were tested in the flanks or upper back areas. In mice, mechanical hypersensitivity on the hind paw to von Frey hairs and response to cold following a drop of acetone were measured. Sinomenine was administered i.p. in rats and p.o. in mice at 10:00 and 16:00, twice a day for 5 days. Response threshold before and 2 h after drug administration at 10.00 h was recorded. Results Repeated administration of sinomenine at 10 or 20 mg/kg twice a day, doses that have no analgesic effect as single injection, alleviated mechanical, but not cold allodynia in spinally injured rats and the effect was maintained during the 5 day treatment period with no signs of tolerance. Furthermore, the pre-drug response threshold was significantly elevated during repeated treatment with 20 mg/kg sinomenine. Sinomenine administered at 40 mg/kg twice a day for 5 days significantly reduced mechanical and cold alldoynia, elevated pre-drug response threshold without tolerance development in spinally injured rats. Similarly, sinomenine at 80 mg/kg twice a day for 5 days significantly reduced mechanical allodynia in mice with sciatic nerve injury and increased pre-drug response threshold with no sign of tolerance. The effect of sinomenine on response threshold persisted for days after termination of the 5 day drug administration. Conclusions The results suggest that repeated administration of simomenine produced an enhanced anti-allodynic effect without tolerance in rodent models of neuropathic pain. Implications Sinomenine may be tested as a novel analgesic in treating some forms of chronic neuropathic pain in patients.Scandinavian Journal of Pain 06/2014; 5(4). DOI:10.1016/j.sjpain.2014.05.006
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ABSTRACT: Low back pain is a challenge for clinicians and researchers, due to the large variability in clinical presentation, lack of consensus regarding diagnostic criteria or clinical classification; wide variation in course and prognosis, and limited success in identifying effective treatments. However, increasing research efforts has generated an expanding body of evidence on the epidemiology, prognosis and treatment of back pain. This paper presents four key developments in research and clinical practice, and describes how these can influence the future direction of back pain research: (1) the increasing awareness of the impact of low back pain on population health; (2) new approaches to describing and investigating course and prognosis of back pain; (3) the need to better understand the bio-psycho-social mechanisms or pathways that explain impact and long-term outcomes in order to inform intervention research; and (4) the potential for stratified models of care to improve patient outcomes and efficiency of care for back pain.Best practice & research. Clinical rheumatology 10/2013; 27(5):699-708. DOI:10.1016/j.berh.2013.11.001 · 3.06 Impact Factor
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ABSTRACT: Chronic pain represents an immense clinical problem. With tens of millions of people in the United States alone suffering from the burden of debilitating chronic pain, there is a moral obligation to reduce this burden by improving the understanding of pain and treatment mechanisms, developing new therapies, optimizing and testing existing therapies, and improving access to evidence-based pain care. Here, we present a goal-oriented research agenda describing the American Pain Society's vision for the pain research aimed at tackling the most pressing issues in the field.Journal of Pain 10/2014; 15(12). DOI:10.1016/j.jpain.2014.09.004 · 4.22 Impact Factor