Which Patients With Pain Are Likely Drug Abusers?

A new study proposes a series of risk factors for identifying primary-care patients with chronic pain who are most likely to abuse prescription medications and other drugs. However, there are some hazards inherent in applying such stereotypes in everyday clinical practice.

Researchers from Boston University School of Medicine enrolled 597 participants in their study at an urban academically-affiliated hospital [Liebschutz et al. 2010]. Subjects were 18 to 60 years old (mean age 46 years), 41% male, 61% black, largely unemployed and poor, and all had pain for >3 months and were taking prescription or nonprescription analgesics. More than half (58%) of participants had no lifetime history of any substance-use problem; however, roughly 18% (n=110) were assessed as having a prescription drug use disorder (PDUD) — of whom most (90%, n=99) also had an additional substance use disorder (SUD) — and 24% had an SUD other than abuse of prescription drugs.

Read more »

Grapefruit Juice Alters Oxycodone Concentration

Grapefruit juice alters the concentrations of many CYP3A4 liver enzyme substrates, including some but not all opioid analgesics. A recent investigation verified that oxycodone concentrations are increased if taken in conjunction with grapefruit juice; however, there can be interactions with other agents as well.

Researchers in Finland had 12 healthy volunteers ingest about 7 ounces (200 mL) of grapefruit juice three times a day (about 2.5 cups/day) for 5 days, and 10 mg oxycodone was administered on day 4 [Nieminen et al. 2010]. Grapefruit juice inhibited the first-pass metabolism of oxycodone by CYP3A4 enzymes in the liver; consequently, oxycodone plasma concentrations were significantly increased by 50% and the half-life was extended by 20%. At the same time, the formation of oxymorphone was increased and formation of noroxycodone and nor-oxymorphone metabolites was decreased. Interestingly, the analgesic effect of oxycodone was not affected and the authors further note that “pharmacodynamic changes were modest and only self-reported performance significantly impaired after grapefruit juice.”

Read more »

Coping Skills Essential for Managing Chronic Pain

Speaking at the American Pain Society’s annual scientific meeting in early May 2010, Francis J. Keefe, PhD, from the Pain and Palliative Care Initiative at Duke University Medical Center, suggested that how individuals cope with and appraise disease-related pain, such as from arthritis or cancer, is related not only to their experience with pain but also to their neurobiological and psychological functioning. In his presentation, he said, “We are clearly observing that studies of coping help us to better understand variations in pain and disability.”

“What seems to be especially important in comprehending persons with disease-related pain is catastrophizing, or the tendency to focus on and exaggerate the threat value of painful stimuli and negatively evaluate one’s own ability to deal with pain. We already know that pain catastrophizing is key to understanding chronic pain,” he added.

Read more »

Study Supports Acupuncture for Pain Control

Researchers testing three types of acupuncture found that pain-tolerance thresholds were increased and, of some importance, positive effects were noted in both the treated and untreated sides of the body.

Philip Lang, PhD, and colleagues from the University of Munich, writing in the May 2010 edition of Anesthesia & Analgesia, describe using quantitative sensory testing to identify changes in pain sensitivity with acupuncture in 24 healthy volunteers (12 men, 12 women). The 3 forms of acupuncture tested were (a) manual acupuncture, (b) acupuncture with low-frequency electrical stimulation, and (c) acupuncture with high-frequency electrical stimulation. In a cross-over design, all treatments were performed by an experienced acupuncturist and applied to only one leg at standard acupuncture points commonly used in pain management. The heat pain threshold was increased after manual acupuncture on both the treated and untreated side compared with baseline. Low- and high-frequency electrostimulation led to a higher mechanical pain threshold on only the treated side compared with baseline and manual acupuncture. The pressure pain threshold was increased by all forms of acupuncture on both sides, with individual changes from baseline ranging up to 52%.

According to news reports (Newswise 4/30/10), the researchers believe their study provides scientific support for the ancient practice of acupuncture. Some of the results demonstrated that stimulation on one side of the body may also incur significant pain relief on the other side (contralateral), which suggests that acupuncturists can beneficially needle the unaffected side of the body if the affected side is too painful or not accessible — for example, if the skin is injured or there is a dressing in place on the affected side. However, this was a small study and some of the outcomes were modest, so it will be important that the results are replicated by further research.

REFERENCE: Lang PM, Stoer J, Schober GM, et al. Bilateral acupuncture analgesia observed by quantitative sensory testing in healthy volunteers. Anesth Analg. May 2010(May);110(5):1448-1456 [full article here].

Behavioral Therapy Helps Calm Painful IBS

Pain and the Great Brain Robbery! Part 4

Cognitive behavioral therapy rapidly improves irritable bowel syndrome (IBS) in a significant number of sufferers, new research reports, and the benefits persist at least several months. Along with that, other research suggests that IBS actually may be a brain disorder.

Researchers at the State University of New York, Buffalo, New York, tested effects of cognitive behavioral therapy (CBT) in adults diagnosed with IBS, a condition characterized by bouts of abdominal cramps, bloating, and changes in bowel habits — diarrhea or constipation, or sometimes alternating episodes of both [Lackner et al. 2010]. It is estimated that as many as 1 in 5 U.S. adults have symptoms of IBS, with women being affected twice as often as men.

The study included 71 individuals (aged 18-70 years) whose IBS symptoms were of at least moderate severity. Patients were assigned randomly to undergo either a wait list control, 10 weekly 1-hour sessions of CBT, or four 1-hour CBT sessions over 10 weeks. CBT aims to help people with IBS recognize their symptom triggers and learn practical ways to manage them. For example, as one task patients "self-monitored," keeping close track of their symptoms, the circumstances under which they occurred, and their thoughts, feelings, and physical responses before and after the flare-ups.

Read more »

Vitamin D: Does Too Much Incur Worse Pain?

A new study raises questions about the harms versus benefits of high-dose vitamin D supplementation in preventing painful falls and fractures. However, as much as anything, this study is a lesson in how consumers of research need to more closely examine and be more critical of published evidence.

Writing in the Journal of the American Medical Association (JAMA), Kerrie Sanders, PhD, and colleagues from the University of Melbourne, Australia, recount a randomized controlled study in which 1,131 women (aged ≥ 70 years) were orally administered a once-yearly dose of 500,000 IU vitamin D3 [Sanders et al. 2010]. An equivalent number of women (n=1,123) received placebo. Contrary to expectations, those receiving vitamin D had a significantly greater incidence of painful falls and bone fractures, compared with the placebo group, and the largest increases occurred within 3 months of dosing.

Read more »

Do Men & Women Differ in Opioid-Abuse Risks?

A study recently published in the Journal of Pain found important differences between men and women that determine risks for abuse of opioid analgesics prescribed for chronic noncancer pain. However, the indiscriminate application of such stereotypes may hinder effective pain management.

Researchers affiliated with Harvard Medical School enrolled 275 male and 335 female patients who had been prescribed opioid analgesics for chronic noncancer pain in a longitudinal predictive study. Participants were asked to complete a series of baseline questionnaires, including the revised Screener and Opioid Assessment for Pain Patients (SOAPP-R). After 5 months, subjects were administered the Prescription Drug Use Questionnaire (PDUQ) and submitted a urine sample for toxicology assessment. Their treating physicians also completed a substance misuse behavior checklist (Prescription Opioid Therapy Questionnaire; POTQ).

Read more »

Who Seeks Alternative Medicine for Pain Relief?

A new study appearing in the journal Pain Medicine highlights the important role of complementary and alternative medicine (CAM) among patients with chronic pain. Along with this, however, there may be concerns about CAM safety and effectiveness, and the fact that patients often do not inform their healthcare providers of CAM use.

The study, from the University of Michigan Health System, retrospectively examined data from 5,750 patients collected during 1994 to 2000 [Ndao-Brumblay and Green 2010]. Investigators found that 1 out of 3 participants with chronic pain reported using CAM therapies for chronic pain relief: specifically, 8.3% used acupuncture, 13.0% used biofeedback/relaxation, and 24.9% used manipulation techniques (eg, chiropractic or physical therapy procedures). A number of trends also were reported:

Read more »

Pain, the Limbic System, and the Triune Brain

Pain and the Great Brain Robbery! Part 3

The previous two entries to date in this series [here] and [here] alluded to the importance of the limbic system in mediating and controlling the experience of chronic pain and its impact on the individual. Before going further, it is clinically important to understand how the limbic system fits into an overall schema described as the “triune brain.”

Long ago, neurologist Paul MacLean, MD, proposed that the human skull functionally holds not one brain, but three, each representing a distinct evolutionary stratum that formed upon the older layer coming before it — somewhat like an archaeological site. He called this the "triune (3-part) brain" and the three components were referred to as the neocortex, the limbic system, and the reptilian brain [see illustration]. Each is intimately connected by nerves to the other two, but each also seems to operate independently and with distinct capacities.

Read more »

Are Overweight Women at Risk of Fibromyalgia?

Overweight and obese women — especially those who do not exercise — are at higher risk for developing fibromyalgia syndrome, according to new research in the May 2010 issue of Arthritis Care & Research. However, this may be more a case of flawed research than actual fact.

Researchers at the Norwegian University of Science and Technology, Trondheim, Norway, retrospectively examined survey data collected during 1984 to 1986 from a large longitudinal sampling of females (n=15,990) without fibromyalgia syndrome or physical impairments at baseline [Mork et al. 2010]. Physical exercise (frequency, duration, and intensity) and body mass index (BMI) were recorded at baseline and these data were subsequently used to assess the risk of having fibromyalgia at an 11-year followup during 1995 to 1997.

Read more »

Errors in Opioid Rx for Cancer Pain Revealed

Most persons with cancer experience pain but it can be effectively managed in almost all cases. Unfortunately, guidelines for effective opioid prescribing in these patients are not being followed, according to research evidence.

Past reports have noted that 70% of persons with cancer experience significant pain and, despite the fact that such distress can be effectively controlled in up to 90% of those patients by following currently available opioid-prescribing guidelines, fewer than half receive adequate pain relief. Writing in the April 2010 edition of the Journal of Pain and Symptom Management researchers at the Cleveland Clinic Palliative Medicine Program (PMP) examined the appropriateness of opioid-prescribing patterns in 186 consecutive patients with cancer [Shaheen et al. 2010]. Appropriateness criteria were derived from several well-established guidelines. In total, 63% (n=117) of the subjects had cancer pain and 151 opioid-prescribing errors were detected; in some patients multiple errors were present. Most common were failure to order around-the-clock opioids for constant pain and the failure to prevent or treat opioid-related side effects. Multiple errors were more common in females than males, but this difference did not reach statistical significance. There was no difference in the errors by level of pain severity.

COMMENT: This recent article by Shaheen and colleagues [2010] is actually an update of a conference presentation from more than 6 years ago by essentially the same group [Davis et al. 2004]. During those intervening years they accumulated only an additional 22 cases in their study, raising questions about timeliness of the data and publication bias. In the earlier presentation, 250 prescribing errors were reported in 164 subjects, with 70% of patients having at least one error. A significant portion (40%) were “strategy errors”; eg, not matching opioid therapy properly to the type, severity, and/or temporal patterns of cancer pain. Despite the inconsistencies of reporting between the original presentation and the final published study, and the relatively small size of the study overall, it seems apparent that many practitioners are not adequately trained in treating cancer pain and/or in following accepted opioid-prescribing guidelines.

REFERENCES:
> Davis MP, Estfan B, Declan W, et al. Errors in opioid dosing principles: A prospective survey. 2004 ASCO Annual Meeting Proceedings [post-meeting ed.]. J Clin Oncol. 2004;22(14S): Abstract #8059 [available here].
> Shaheen PE, LeGrand SB, Walsh D, et al. Errors in opioid prescribing: A prospective survey in cancer pain. J Pain Sympt Manage. 2010(Apr);39(4):702-711 [abstract].

Further Insights on NSAID Risks & Rx Strategies

Painful musculoskeletal disorders are prevalent and their impact is pervasive. Nonsteroidal anti-inflammatory drugs (NSAIDs) are often first-line analgesic therapy; however, there are multiple risks and drug interactions to consider when developing optimal strategies for their use.

NSAIDs have a well-established place in the management of osteoarthritis (OA) and rheumatoid arthritis (RA) but they are associated with significant risks, which we have noted in a prior blogpost [here]. Now, a new supplemental edition of the journal Rheumatology explores these concerns from the perspectives of a gastroenterologist, a rheumatologist, and a family practitioner. The entire supplement, which is supported by a grant from Pfizer Inc., is available for free viewing [here].

Read more »

May2010 – Pain Product Announcements & Warnings

Featured Items: naproxen+esomeprazole (Vimovo) FDA approved; recall – children’s/infant’s Tylenol, Motrin, Zyrtec, and Benadryl; lidocaine patch 5% (Lidoderm) labeling revision; oxycodone controlled-release (OxyContin) reformulation approval.
— Brand names are trademarks of their respective manufacturers. Compiled by Winnie Dawson, MA, RN, BSN.

Naproxen + Esomeprazole (Vimovo™) — FDA Approved
The U.S. Food and Drug Administration has approved AstraZeneca Plc and Pozen Inc's pain drug Vimovo. This is a fixed-dose combination of the anti-inflammatory drug naproxen and an immediate release version of esomeprazole, a proton pump inhibitor and the active ingredient in AstraZeneca's acid reflux treatment Nexium®. Vimovo was approved for relieving symptoms of osteoarthritis, rheumatoid arthritis, and a type of spinal arthritis called ankylosing spondylitis. It also was cleared for decreasing the chances of gastric ulcers in patients at risk of developing them from use of nonsteroidal anti-inflammatory drugs, or NSAIDs. Press release [here].

Recall — Children’s/Infant’s Tylenol®, Motrin®, Zyrtec®, and Benadryl®
McNeil Consumer Healthcare and the FDA notified healthcare professionals of a voluntary recall of certain over-the-counter (OTC) children’s and infants’ liquid products manufactured in the United States, including Tylenol, Motrin, Zyrtec, and Benadryl products. Some of these products may not meet required quality standards. This recall is not being undertaken on the basis of adverse medical events. However, as a precautionary measure, parents and caregivers should not administer these products to their children or infants. These products were distributed in the United States, Canada, Dominican Republic, Dubai (UAE), Fiji, Guam, Guatemala, Jamaica, Puerto Rico, Panama, Trinidad and Tobago, and Kuwait. See announcement [here].

Lidocaine Patch 5% (Lidoderm®) — Labeling Revision
Endo Pharmaceuticals has provided additional safety information to the Lidoderm label. The Lidoderm patch is a local anesthetic used to treat post-herpetic neuralgia, a pain disorder than sometimes follows shingles. The 'Precautions' section of the label contains a new subsection on 'External Heat Sources' to alert patients that additional heat from sources such as electric blankets should not be used over the Lidoderm patch. Read the April 2010 revised label for full information.

Oxycodone HCl (OxyContin®) — New Controlled-Release Tablet Approval
Purdue Pharma announced the April 2010 approval of a new controlled-release formulation of the opioid pain-reliever OxyContin. This reformulation has been designed to prevent the tablet from being cut, broken, chewed, crushed, or dissolved — to discourage misuse and abuse of the medication. The new OxyContin tablets will be produced in 7 different dosing strengths and are scheduled to be available during the 3rd quarter of 2010. At that time, the original controlled-release formulation of the product will be discontinued. As required by the FDA's Risk Evaluation and Mitigation Strategy (REMS) program, Purdue has provided Prescribing Information and a Medication Guide (combined) for the new OxyContin product.