Research published in the Journal of Addictive Diseases has discovered that among chronic pain patients, there is a high occurrence of addiction to prescription pain medicine and, although it was hoped that the American Psychiatric Association‘s new addiction definition would lower the number of people considered addicts who take these prescription medicines, the actual results demonstrated that the percentage of people meeting addiction criteria stayed the same.
One study author, Joseph Boscarino (Center for Health Research, Geisinger Clinic, Danville, PA, USA) stated that, “Most patients will not know if they carry the genetic risk factor for addiction. Improper or illegal use of prescription pain medication can become a lifelong problem with serious repercussions for users and their families.” He goes on to say, “Genetic predisposition to addiction further exacerbates the risks associated with misuse of prescription pain medication.”
Investigators in the study used electronic records from a healthcare system to obtain a random sample of outpatients who were going through long-term opioid therapy for noncancer pain. The diagnostic interviews were completed by a total of 705 subjects, and nonrespondents totaled 1434.
The authors state that, “The proposed diagnostic criteria for the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) includes modifications for prescription opioid-use disorders.”
The investigators set out with three main objectives:
▪ To examine the predominance of DSM-5 prescription opioid-use disorder in an ‘at-risk‘ population;
▪ To highlight the main risk factors associated with the new classification system;
▪ To compare criteria between DSM-4 and DSM-5 to help future research directions.
results were somewhat surprising. The study demonstrated that 34.9% (95% CI: 30.5–39.5) of patients in long-term opioid therapy met the criteria required for “lifetime prescription opioid-use disorder” according to the new DSM-5 criteria. The authors highlighted that this percentage was almost the same percentage that met the criteria according to DSM-4. This result was unexpected – especially due to the differences between the diagnostic criteria of DSM-4 and DSM-5.
The authors concluded that, “Further clinical and epidemiological research is urged to clarify and expand these findings.” Boscarino states that, “Ultimately, we hope our research will aid the development of newer classes of medication that don‘t negatively impact the brain and therefore avoid addiction entirely.”
Sources: Boscarino JA, Rukstalis MR, Hoffman SN et al. Prevalence of prescription opioid-use disorder among chronic pain patients: comparison of the DSM-5 vs. DSM-4 diagnostic criteria. J. Addict. Dis. 30(3), 185–194 (2011); Geisinger News Room: https://webapps.geisinger.org/ghsnews/articles/Newstudyprescriptionpainm9254.html
Homeless populations have much higher incidences of chronic pain than the general population. Despite this, a new study has shown that chronic pain is poorly managed in this population, leading to increased use of street drugs and alcohol where there is no provision for prescribed chronic pain medication. Levels of chronic pain lasting at least 6 months in the general population were reported as 25% in the publication, and are expected to be a lot higher in the homeless population.
The article was published online in the journal BMC Family Practice by a group of investigators from St Michael‘s Hospital and the University of Toronto (Toronto, ON, Canada) led by Stephen Hwang, and is thought to be one of the first peer reviewed publications evaluating chronic pain management in homeless populations.
The study randomly enrolled participants from single adult homeless shelters across Toronto who reported chronic pain. The participants were then categorized by severity of chronic pain; of the 152 homeless people enrolled in this study, 37% reported high-intensity debilitating chronic pain (Chronic Pain Grade IV).
Only 51% of the patients experiencing chronic pain were receiving pain relieving medication to manage the problem, whereas 46% were using street drugs to manage their pain, and 29% were using alcohol. When questioned, the homeless populations viewed the stress of living in shelters, inability to afford prescription medications and poor sleeping conditions as major barriers to pain management.
The authors also interviewed the participants‘ physicians where possible, and found that there were difficulties in managing pain in this population, including history of addiction to other substances, maintaining regular appointments and mental illness.
“Our study demonstrates the need for improved approaches to the management of chronic pain in the homeless population,” commented Dr Hwang. “Clinicians should also inquire about barriers to pain management, such as financial ability to obtain appropriate over-the-counter and prescription medications. The adverse effects of homeless people‘s living and sleeping conditions should also be considered.”
More investigations should be undertaken to further elucidate the problem among this and other minority populations. Improved screening of defined populations known to have increased incidence of chronic pain should also be implemented.
Source: Hwang SW, Wilkins E, Chambers C, Estrabillo E, Berends J, MacDonald A. Chronic pain among homeless persons: characteristics, treatment, and barriers to management. BMC Family Practice DOI: 10.1186/1471-2296-12-73 (2011) (Epub ahead of print).
St Jude Medical has announced the US FDA clearance and limited market release of its Epiducer™ lead delivery system for neurostimulation therapy. Also known as spinal cord stimulation, neurostimulation is commonly used for the management of chronic pain of the trunk and limbs and pain from failed back surgeries. By placing lead/s in the epidural space near the spine of a patient, mild electrical pulses are carried from the neurotransmitter that act to interrupt or mask the transmission of pain signals to the brain.
The Epiducer provides a minimally invasive system that enables physicians to deliver one, two or three different leads through a single entry point to configure and optimize therapy for individual patients. The system also allows for the management of complex and multifocal pain patterns such as lower back pain combined with leg pain. In addition the system enables physicians to introduce paddle leads through a percutaneous entry, the placement of which was only possible through a laminotomy, a more invasive surgical procedure that typically requires removal of part of the vertebral bone.
Source: St Jude Medical Newsroom: http://investors.sjm.com/phoenix.zhtml?c=73836&p=irol-newsArticle&ID=1584193
According to a recent study published in Breast Cancer Research & Treatment, high-dose vitamin D appears to reduce muscle and joint pain in a number of breast cancer patients who are taking aromatase inhibitors or estrogen-lowering drugs.
The drugs are prescribed to patients to shrink ‘estrogen-fueled‘ tumors in the breast. They can also aid in preventing the cancer from returning. Although these aromatase inhibitors prove to be less toxic than chemotherapy, patients can experience unwanted symptoms, such as musculoskeletal discomfort and stiffness and pain in areas including the knees, lower back and hands.
Antonella Rastelli (Washington University School of Medicine, St Louis, MO, USA), first author of the paper explains, “About half of patients can experience these symptoms. We don‘t know exactly why the pain occurs, but it can be very debilitating – to the point that patients decide to stop taking aromatase inhibitors.”
In the double-blind, placebo-controlled, randomized Phase II trial, study investigators wanted to “determine whether high dose vitamin D2 supplementation in women receiving adjuvant anastrozole improves aromatase inhibitor-induced musculoskeletal symptoms and bone-loss.” The 60 patients studied were divided into groups – one group were randomly assigned to receive 400 IU of vitamin D (the recommended daily dose) together with a 50,000-unit vitamin D capsule taken once weekly. The remaining group received a 400 IU daily dose of vitamin D, along with a placebo given weekly. For the entire study, patients received 1000 mg of calcium.
To assess aromatase inhibitor-induced musculoskeletal symptoms, investigators used the Brief Pain Inventory – Short form, the Fibromyalgia Impact Questionnaire and the Health Assessment Questionnaire-Disability Index. These were used at baseline, and then at 2, 4 and 6 months. Scientists also measured bone mineral density. Authors write that the study‘s primary end point was “the change-from-baseline musculoskeletal pain.”
Rastelli states, “High-dose vitamin D seems to be really effective in reducing the musculoskeletal pain caused by aromatase inhibitors. Patients who get the vitamin D weekly feel better because their pain is reduced and sometimes goes away completely. This makes the drugs much more tolerable. Millions of women worldwide take aromatase inhibitor therapy, and we may have another ‘tool‘ to help them remain on it longer.”
She also states, “It‘s great that we have something as simple as vitamin D to help patients alleviate some of this pain. It‘s not toxic – it doesn‘t cause major side effects. And if it is actually protecting against bone loss, that‘s even better.”
Vitamin D aids the body in calcium absorption. Therefore, elevated levels of vitamin D can result in increased urine calcium levels and thus increase risk of kidney stone formation. Rastelli explains, “It‘s important to monitor the patients, but overall it appears to be very safe. Because vitamin D2 is eliminated from the body so quickly, it‘s very hard to overdose.”
The outcomes of this study are certainly of interest and further investigations need to be carried out to build on these results.
Sources: Rastelli AL, Taylor ME, Gao F et al. Vitamin D and aromatase inhibitor-induced musculoskeletal symptoms (AIMSS): a Phase II, double-blind, placebo-controlled, randomized trial. Breast Cancer Res. Treat. 129(1), 107–116 (2011); Washington University in St Louis Newsroom: http://news.wustl.edu/news/Pages/22523.aspx
In a recent study, scientists have demonstrated that the diabetes drug rosiglitazone also appears to control inflammation that leads to damage of the nerves and neuropathic pain. Neuropathic pain is quite common and is hard to treat. It can occur in patients with a variety of conditions, such as diabetes and trauma. One example of neuropathic pain is phantom limb pain that occurs postamputation.
In their paper, the authors state that this neuroinflammation is triggered by infiltration of macrophages into peripheral nerve injury sites. The properties of macrophages are regulated by peroxisome proliferator-activated receptor (PPAR)-γ signaling, but there have not been any studies into the macrophage-mediated effects of signaling on neuropathic pain triggered as a result of peripheral inflammation.
Investigators set out to examine the “peripheral effects of PPAR-γ signaling on tactile allodynia,” using rosiglitazone administered in different ways. Tactile allodynia describes painful responses to things such as light touch – a process that does not normally induce pain. Authors describe rosiglitazone as a blood–brain barrier-impermeant PPAR-γ agonist, and the drug was given after partial sciatic nerve ligation.
Results of the study demonstrated that tactile allodynia development was “significantly alleviated” as a result of rosiglitazone treatment in the early phase of neuropathic pain. This was due to the regulation of the infiltration of macrophages, and the production of proinflammatory molecules at the location of inflammation.
Yoshika Takahashi (Juntendo University School of Medicine, Tokyo, Japan) states, “We therefore propose PPAR-γ regulation of the macrophage-mediated inflammatory response as a novel therapeutic target for treating neuropathic pain development.” In reference to the results published in Anesthesia & Analgesia, Takahashi and co-authors write, “Our results indicate that the activation of PPAR-γ signaling in macrophages during the early phase may suppress neuropathic pain development.”
Further research could lead to novel approaches for the treatment of neuropathic pain.
Sources: Takahashi Y, Hasegawa-Moriyama M, Sakurai T, Inada E. The macrophage-mediated effects of the peroxisome proliferator-activated receptor-γ agonist rosiglitazone attenuate tactile allodynia in the early phase of neuropathic pain development. Anesth. Analg. 113(2), 398–404 (2011); International Anesthesia Research Society Newsroom: www.newswise.com