A new role for opioids in the treatment of arthritis

Narcotic analgesics

There is documentation of the use of opium derived products in the ancient history of the Assyrians: the Egyptians; in the sixth century AD by the Roman Dioscorides; and by Avicenna (980-1037). Reference to opium like products is made by Paracelsus and by Shakespeare. Charles Louis Derosne and Fredrich Wilhelm Adam Serturner isolated morphine from raw opium in 1802 and 1806 respectively, and it was Sertürner who named the substance morphine, after Morpheus, the Greek God of dreams. By the middle 1800s, Opium and related opioid derived products were the source of a major addiction in USA, and to some extent in the United Kingdom. Opioid products are of major therapeutic value in the treatment of pain from injury, post surgery, intractable pain conditions, and some forms of terminal cancer.

Modulating β-arrestin 2 recruitment at the δ- and μ-opioid receptors using peptidomimetic ligands

μ-Opioid receptor agonists provide potent and effective acute analgesia; however, their therapeutic window narrows considerably upon repeated administration, such as required for treating chronic pain. In contrast, bifunctional μ/δ opioid agonists, such as the endogenous enkephalins, have potential for treating both acute and chronic pain. However, enkephalins recruit β-arrestins, which correlate with certain adverse effects at μ- and δ-opioid receptors. Herein, we identify the C-terminus of Tyr-ψ[(Z)CF[double bond, length as m-dash]CH]-Gly-Leu-enkephalin, a stable enkephalin derivative, as a key site to regulate bias of both δ- and μ-opioid receptors. Using in vitro assays, substitution of the Leu⁵ carboxylate with amides (NHEt, NMe₂, N^CyPr) reduced β-arrestin recruitment efficacy through both the δ-opioid and μ-opioid, while retaining affinity and cAMP potency. For this series, computational studies suggest key ligand-receptor interactions that might influence bias. These findings should enable the discovery of a range of tool compounds with previously unexplored biased μ/δ opioid agonist pharmacological profiles.

Factors associated with potentially problematic opioid prescriptions among individuals with private insurance and medicaid

If opioid analgesics are prescribed and used inappropriately, they can lead to addiction and other adverse effects. In this study, we (1) examine factors associated with potentially problematic opioid prescriptions and (2) quantify the link between potentially problematic prescriptions and the development of opioid use disorder. We found that older age; female sex; having back pain, arthritis, or migraine; hydrocodone prescription; previous pharmacotherapy for opioid use disorder; and frequent emergency department use were associated with problematic prescriptions among individuals with Medicaid and private insurance. Patients with commercial insurance and Medicaid who had potentially problematic opioid prescriptions were eight and three times more likely, respectively, to develop an opioid use disorder than patients without potentially problematic opioid prescriptions. Our findings help identify factors associated with problematic prescriptions and underscore the importance of targeted public health interventions.

Results of a double-blind, placebo-controlled, fixed-dose assessment of once-daily OROS® hydromorphone ER in patients with moderate to severe pain associated with chronic osteoarthritis

OBJECTIVE

Opioids are recommended for patients with moderate to severe pain due to osteoarthritis (OA), who do not receive adequate analgesia from nonopioid treatment. The objective of this study was to evaluate the efficacy and safety of OROS hydromorphone extended-release (ER) compared with placebo in patients with moderate to severe pain associated with OA.

METHODS

This was a randomized, placebo-controlled, double-blind, fixed-dose study. Patients received placebo or fixed-dose OROS hydromorphone ER (8 or 16 mg). The primary efficacy measure was pain intensity score (11-point Numeric Rating Scale) at Maintenance Week 12, analyzed with baseline observation carried forward (BOCF) imputation for missing data.

RESULTS

This study did not meet the primary efficacy measure using the BOCF imputation. Study discontinuation was high (52%). When analyzed using last observation carried forward (LOCF) imputation, the prespecified alternate method, OROS hydromorphone ER 16 mg provided significantly better analgesia than placebo (P = 0.0009). Treatment was associated with significant improvements in patient global assessment (P = 0.01), the overall Western Ontario and McMaster Osteoarthritis Index (WOMAC) (P = 0.0003), and its subscales: pain (P = 0.0001), stiffness (P = 0.0023), and physical function (P = 0.0006). Gastrointestinal adverse events, such as constipation and nausea, were common among patients receiving OROS hydromorphone ER.

CONCLUSIONS

OROS hydromorphone ER failed to achieve statistical significance for the primary endpoint using the prespecified imputation method (BOCF), likely due to the high discontinuation rate associated with the fixed-dose design. When data were analyzed according to an alternate method of imputation (LOCF), OROS hydromorphone ER demonstrated statistically significant improvements in pain, stiffness, and physical function.

The NSAID dilemma: managing osteoarthritis in high-risk patients

For decades, evidence-based data and reported experience have warned that the common chronic oral nonsteroidal anti-inflammatory drug (NSAID) therapy for osteoarthritis (OA) in elderly patients is ultimately dangerous. Elderly patients with OA are at heightened risk for developing serious gastrointestional and cardiovascular adverse events, including gastrointestinal bleeding, myocardial infarction, and stroke. Prescribing NSAIDs, especially in an elderly population, continues to be discouraged because of these significant risks. A dilemma exists for individuals who need the established efficacy associated with oral NSAIDs but who are at increased risk for serious adverse events associated with these agents. The goal of this clinical review was to evaluate the risks versus benefits of current options in the treatment of OA. This review found that topical NSAIDs seem to be the safest choice among all options to mitigate gastrointestinal and cardiovascular risks and should be considered prior to the initiation of oral nonselective or cyclooxygenase (COX)-2-selective NSAIDs for individuals presenting with a localized expression of OA. Further research is needed to evaluate and compare these therapies in treating both pain and inflammation effectively while mitigating safety risks in high-risk populations.

[Physicians' knowledge and attitudes concerning the use of opioids in the treatment of chronic cancer and non-cancer pain]

INTRODUCTION

The efficacy of opioids has been proved and several guidelines and expert panel-based recommendations regarding the use of opioids in different pain syndromes are available. Nevertheless, undertreatment of pain with strong opioids was reported in previous studies. It was shown that physicians' lack of knowledge, their concerns and misconceptions about the opioid use and the controlled substances regulations that govern the prescriptions of opioids occasionally contribute to insufficient pain treatment. This study was designed to evaluate German physicians' knowledge and their concerns about the use of opioids.

METHOD

During a postgraduate course a questionnaire was completed by German physicians specializing in pain therapy.

RESULTS

A total of 226 physicians completed the questionnaire (response rate 57%). Many of them had poor knowledge of the WHO recommendations for the treatment of cancer pain including the WHO analgesic ladder. Deficiencies in the knowledge of pharmacological aspects and controlled substances regulations were revealed. Many physicians would prescribe strong opioids for non-opioid-sensitive types of pain. The concerns regarding opioid therapy included adverse effects and addiction. In contrast to earlier findings the German controlled substances regulations no longer seem to be a barrier to the prescription of opioids in the treatment of chronic severe pain since they were changed in 1998. As a result, the lack of knowledge and the physicians' concerns about the use of opioids as shown in this survey may likely lead to an insufficient treatment of patients suffering from severe chronic pain.

CONCLUSION

It is necessary to improve the medical students' education and the physicians' postgraduate training regarding principles of pain management such as the WHO guidelines for the treatment of cancer pain. A better knowledge of important pharmacological aspects of opioids should help to reduce physicians' concerns about the use of strong opioids. Nevertheless, improvement of physicians' skills in pain therapy is only one aim in a multidisciplinary concept in order to improve patients' pain therapy.

Do Patients' Beliefs Act as Barriers to Effective Pain Management Behaviors and Outcomes in Patients With Cancer-Related or Noncancer-Related Pain?

PURPOSE/OBJECTIVES

To understand the role of patients' beliefs in pain management in a cancer population treated in a primary care setting.

DESIGN

Secondary analyses of data from the baseline phase of a randomized study.

SETTING

Eight of the largest primary care clinics in a managed care system.

SAMPLE

342 patients with cancer who reported pain that would not dissipate on its own or when treated by over-the-counter medication; approximately half had pain that was not cancer related.

METHODS

Telephone interviews.

MAIN RESEARCH VARIABLES

Patients' demographic characteristics, self-reported history and beliefs about pain and pain treatment, willingness to report pain and take pain medication, recent pain intensity, and administrative data on opioid prescriptions.

FINDINGS

Patients' beliefs were not associated strongly with reporting pain or taking medication. Regression analyses revealed that patients' beliefs played a limited role in predicting recent pain intensity, whereas the providers' pain management practices seemed to have a far greater predictive role. Additionally, among patients with recent moderate to severe pain, the relationship between patients' beliefs and their history of pain and pain treatment further suggests that beliefs are likely to be formed, in part, as a consequence of the care they receive. Results did not depend on whether the cause of pain was related to cancer.

CONCLUSION

Patients' beliefs were important barriers to effective pain management, either as direct or indirect determinants of pain. Providers' pain management practices were more likely to determine the level of pain relief achieved and the beliefs their patients came to hold based on their personal experiences.

IMPLICATIONS FOR NURSING

Nursing interventions should examine the impact of evaluating patients' beliefs in conjunction with pain assessment on pain-related behaviors and pain relief, as well as the ability of patient educational efforts to strengthen accurate beliefs and enable patients to assert themselves when interacting with less knowledgeable providers.

[Effectiveness of a pharmaceutical care unit for the control of severe chronic pain]

INTRODUCTION

The effectiveness of a pharmaceutical care unit was assessed within a staged program for non-malignant severe chronic pain control in a multidisciplinary pain management unit at Consorcio Hospital General Universitario, Valencia, Spain.

MATERIALS AND METHODS

One hundred and fifty patients with clinical indication for a major opioid were included in WHO's third analgesic rung by our medical team following careful triage. The pharmaceutical care unit, or phase II, monitored dosage titration for pain stabilization with absence of side effects, as well as the onset of subsequent chronic therapy.

RESULTS

Upon program completion 75% of patients had their pain under control, having required 22.7 days on average for opiate dose titration. Mean daily dose was 22.3 mg, and constipation was prophylactically managed from the start. Fifty-nine percent of patients received subsequent chronic therapy with fentanyl transdermal patches at 25 microg/h; 10% followed suit with oral morphine solution, and 6% with controlled-release morphine. Twenty-five percent of the remaining patients had relevant events during the therapy titration stage, which led to therapy discontinuation and discharge because of lack of therapeutic effectiveness. After 24 months 70% of patients were still on initial doses.

CONCLUSIONS

The effectiveness of our unit was demonstrated by the achievement of the program objectives.

Transdermal buprenorphine

Buprenorphine is a low molecular weight, lipophilic, opioid analgesic. Recently, a transdermal matrix patch formulation of buprenorphine has become available in three dosage strengths designed to release buprenorphine at 35, 52.5 and 70 micro g/h over a 72-hour period. At least satisfactory analgesia with minimal requirement for rescue medication (</=0.2 mg/day sublingual buprenorphine) was achieved by 34-50% of patients with chronic pain treated with transdermal buprenorphine 35, 52.5 or 70 micro g/h and 31% of placebo recipients, in one double-blind, placebo-controlled, randomised trial. In one trial involving patients unsuccessfully treated with weak opioids or morphine, 36.6% and 47.5% of buprenorphine 35 micro g/h and 52.5 micro g/h recipients, respectively, experienced at least satisfactory analgesia and received </=0.2 mg/day of sublingual buprenorphine compared with 16.2% of placebo recipients (both p </= 0.032). The requirement for rescue medication was reduced from baseline in >50% of patients treated with transdermal buprenorphine, in two trials. Furthermore, despite the availability of rescue medication to all patients, those receiving transdermal buprenorphine tended to experience greater pain relief, reduced pain intensity and longer pain-free sleep. Transdermal buprenorphine was generally well tolerated. Systemic adverse events were typical of opioid treatment or were attributable to the underlying disease.

Pain in hemodialysis patients: prevalence, cause, severity, and management

BACKGROUND

There is growing evidence that dialysis patients have a high burden of symptoms, including pain. However, the prevalence, cause, severity, and management of pain in dialysis patients have not been described.

METHODS

This prospective cohort study of 205 Canadian hemodialysis (HD) patients describes the prevalence, cause, severity, and management of pain in this population. A chart review for demographic and clinical data was conducted, and patients completed a questionnaire that incorporated the Brief Pain Inventory, followed by the McGill Pain Questionnaire.

RESULTS

One hundred three patients (50%) reported a problem with pain. Patients with pain had been on HD therapy longer (52.2 months) than those without pain (37.7 months). Causes of pain were diverse, and 18.4% of patients had more than a single cause of their pain. Musculoskeletal pain was most common (50.5%) and equal in severity to pain associated with peripheral neuropathy and peripheral vascular disease. Fifty-five percent of patients with pain rated their worst episode in the previous 24 hours as severe. Thirty-two percent of patients with pain were administered no analgesics, 29.1% were administered nonopioid analgesics, 26.2% were administered weak opioids, and 9.7% were administered strong opioids. The Pain Management Index describes the effectiveness of pain management and was negative in 74.8% of patients, indicating ineffective management.

CONCLUSION

Pain is a significant problem in more than 50% of HD patients and is not being effectively managed. The development of effective pain management strategies, underpinned by appropriate training and education, is necessary to improve the quality of life for dialysis patients.

Interactions of acute morphine with chronic imipramine and fluvoxamine treatment on the antinociceptive effect in arthritic rats

This study was undertaken to investigate the effects induced by chronic systemic administration of two different antidepressants: imipramine (IMI), a dual serotonin-noradrenaline reuptake inhibitor, and fluvoxamine (FVX), a selective serotonin reuptake inhibitor, on the antinociceptive effect of morphine (MOR) in a paw pressure test in adjuvant-induced arthritic rats. For 30 days rats were administered with IMI, FVX or saline (SAL). On days 15 and 30, animals were tested in the paw pressure test 20 min after MOR or SAL administration. MOR induced a significant antinociceptive effect in IMI, FVX and SAL treated rats. But, at 30 days, this increase in pain threshold was significatively higher in IMI than SAL rats. This increase was not seen in FVX rats. These results suggest that a combination of opioid and mixed monoaminergic activities is effective in enhancing the antinociceptive effect of MOR in arthritic rats while only opioid and serotonergic activities have no enhancer effect.