Impact of long-term use of opioids on quality of life in patients with chronic, non-malignant pain

Relationships of self-reported opioid and benzodiazepine use with health-related quality of life among adults with spinal cord injury

BACKGROUND

There is limited understanding of the relationships between prescription opioid and benzodiazepine use and indices of health-related quality of life (HRQOL) among those with spinal cord injuries (SCI).

OBJECTIVE

To identify the relationships between self-reported prescription opioid and benzodiazepine use and two indicators of HRQOL, number of days in poor physical health and poor mental health in the past 30 days among adults with SCI.

METHODS

A cross-sectional cohort study of 918 adults with chronic (>1 year), traumatic SCI living in the Southeastern United States was conducted. Participants completed a self-report assessment (SRA).

RESULTS

In the preliminary model, both opioid and benzodiazepine use were associated with a greater number of days in poor physical health and poor mental health in the past month. After controlling for health conditions (pain intensity, spasticity, anxiety and perceived sleep insufficiency), opioid use was associated with 2.04 (CI = 0.69; 3.39) additional poor physical health days in the past 30 days, and benzodiazepine use was associated with 2.18 (CI = 0.70; 3.64) additional days of poor mental health. Age was associated with greater number of poor physical health days and fewer poor mental health days. Lower income was associated with poor mental health days. Most of the health conditions were significantly related to the number of past month poor physical and mental health days.

CONCLUSIONS

Opioid and benzodiazepine use are associated with poor physical and mental HRQOL, even after controlling for health conditions. Treatment strategies should consider potential unanticipated negative consequences of pharmacological interventions.

Does opioid therapy enhance quality of life in patients suffering from chronic non-malignant pain? A systematic review and meta-analysis

Background and objective

Chronic pain is associated with a poor health-related quality of life (HRQL). Whereas the prescription rate of opioids increased during the last decades, their use in chronic non-malignant pain remains unclear. However, there is currently no clinical consensus or evidence-based guidelines that consider the long-term effects of opioid therapy on HRQL in patients with chronic non-cancer pain. This systematic review aims to address the question of whether opioid therapy improves HRQL in patients with chronic non-malignant pain and provide some guidance to practitioners.

Databases and data treatment

PubMed, EMBASE and CENTRAL were searched in June 2020 for double-blind, randomized trials (RCTs), comparing opioid therapy to placebo and assessed a HRQL questionnaire. The review comprises a qualitative vote counting approach and a meta-analysis of the Short Form Health Survey (SF-36), EQ-5D questionnaire and the pain interference scale of the Brief pain inventory (BPI).

Results

35 RCTs were included, of which the majority reported a positive effect of opioids for the EQ-5D, the BPI and the physical component score (PCS) of the SF-36 compared to placebo. The meta-analysis of the PCS showed a mean difference of 1.82 [confidence interval: 1.32, 2.32], the meta-analysis of the EQ-5D proved a significant advantage of 0.06 [0.00, 0.12]. In the qualitative analysis of the mental component score (MCS) of the SF-36, no positive or negative trend was seen. No significant differences were seen in the MCS (MD: 0.65 [-0.43, 1.73]). A slightly higher premature dropout rate was found in the opioid group (risk difference: 0.04 [0.00, 0.07], p = .07). The body of evidence is graded as low to medium.

Conclusion

Opioids have a statistically significant, but small and clinical not relevant effect on the physical dimensions of HRQL, whereas there is no effect on mental dimensions of HRQL in patients with chronic non-malignant pain during the initial months of treatment. In clinical practice, opioid prescriptions for chronic non-cancer pain should be individually assessed as their broad efficacy in improving quality of life is not confirmed. The duration of opioid treatment should be determined carefully, as this review primarily focuses on the initial months of therapy.

Pharmacological treatment of pain in Swedish nursing homes: Prevalence and associations with cognitive impairment and depressive mood

OBJECTIVES

Chronic pain is highly prevalent in nursing home residents and often occurs with depression as well as cognitive impairment, which can severely influence and limit the expression of pain.

METHODS

The present cross-sectional study aimed to estimate the prevalence of pain, depressive mood, and cognitive impairment in association with pharmacological treatment against pain and depressive symptoms among Swedish nursing home residents.

RESULTS

We found an overall pain prevalence of 52.8%, a prevalence of 63.1% for being in a depressive mood, and a prevalence of cognitive impairment of 68.3%. Among individuals assessed to have depressive mood, 60.5% were also assessed to have pain. The prevalence of pharmacological treatment for pain was 77.5 and 54.1% for antidepressants. Prescription of pharmacological treatment against pain was associated with reports of currently having pain, and paracetamol was the most prescribed drug. A higher cognitive function was associated with more filled prescriptions of drugs for neuropathic pain, paracetamol, and nonsteroidal anti-inflammatory drugs (NSAIDs), which could indicate an undertreatment of pain in those cognitively impaired.

CONCLUSION

It is important to further explore the relationship between pain, depressive mood, and cognitive impairment in regard to pain management in nursing home residents.

The United States opioid crisis: Big pharma alone is not to blame."

OBJECTIVE

The opioid crisis in the United States continues essentially unabated, fueled by fentanyl contamination of the heroin supply and resulting in 79,770 reported opioid-involved overdose deaths in the calendar year 2022. To prevent another such crisis emerging, it is necessary to fully identify its root causes.

METHODS

Despite the well-recognized role the pharmaceutical industry played in facilitating the crisis via the aggressive marketing of prescription opioids, several other less appreciated but perhaps more influential factors were also contributors, and the overall goal of this review is to ensure that these are not be lost to history in a concerted effort to blame opioid manufacturers and distributors. Presented is a historical review of research and regulatory documents beginning with the loosening of opioid prescription for chronic pain through current thought and practice today. Beginning with a necessary decoupling of the current opioid crisis from the increased use of opioids to treat chronic pain, this review will examine these contributing factors.

RESULTS

Clinical concerns about under- or untreated pain, practice guidelines from standard-setting organizations and government entities, and a health system-wide move away from specialty interdisciplinary pain programs together set the stage for an over-reliance on opioids in chronic pain care.

CONCLUSIONS

This review reminds the health care community that despite the deep pockets of the pharmaceutical industry and highly the organized efforts of the drug cartels, additional self-reflection is warranted to fully understand the true root causes of the current epidemic and ways to prevent similar epidemics in the future.

Guided self-determination in treatment of chronic pain - a randomized, controlled trial

OBJECTIVES

To test whether Guided Self-Determination (GSD) used in chronic pain management could improve the health-related quality of life, patient activation and sense of coherence (SoC) as a measurement of life skills in patients with chronic pain. The method has been shown to be effective in other chronic conditions, but has not been tested in chronic pain.

METHODS

A three-site randomised, controlled trial at three major multidisciplinary pain centres in Denmark. 200 patients were included and randomised. In the intervention period, both groups had regular visits to the pain centre with both doctors and nurses. The intervention group additionally received the GSD intervention with weekly sessions for eight weeks. Data were collected from February 2013 to July 2016 and consisted of three questionnaires answered before and after the 8-week intervention period, and after six months. The primary outcome was self-reported health related quality of life. Secondary outcomes included self-reported activation and SoC.

RESULTS

We found no clinically relevant difference between the groups for health-related quality of life, patient activation or SoC at either baseline, at three months or at six months. We also analysed data for trends over time using mixed model analysis, and this did not show any significant differences between groups.

CONCLUSIONS

GSD did not improve health-related quality of life, patient activation or SoC when administered to patients with chronic pain treated in a multidisciplinary pain centre. New research is recommended using a combination of self-reported and objective measures and longer follow-up.

Efficacy and Safety of Peripherally Acting μ-Opioid Receptor Antagonist (PAMORAs) for the Management of Patients With Opioid-Induced Constipation: A Systematic Review

In treating chronic and acute pain, opioids are widely used. Although they do provide analgesia, their usage does come with adverse events (AEs). One of the most burdensome is opioid-induced bowel dysfunction, and more specifically opioid-induced constipation (OIC). The pathogenesis of these AEs is well known as the consequence of the action of opioids on m-receptors in the enteric nervous system. In recent years, medicines counteracting this specific action at the receptors have been registered for clinical use: the peripherally acting μ-opioid receptor antagonists (PAMORAs). The knowledge of their comparative efficacy and tolerability is very important for physicians and patients in opioid therapy. This systematic review of the existing literature on PAMORAs aimed to study the relative clinical advantages and disadvantages. The most important data banks, including "PubMed," "Embase," "CT.gov," "ICTRP" and "CINAHL" were used to find the published material on PAMORAs. The selected publications were examined to systematically analyze the efficacy and safety of the four existing PAMORAs. All of the medications are superior to placebo in reducing OIC. There are few published data on alvimopan used to treat OIC, and it is only indicated for the treatment of post-abdominal surgery ileus. Methylnaltrexone is studied mainly in its subcutaneous (SC) formulation. When used in its oral formulation, it seems more rapid than naloxegol and placebo in the reduction of OIC. Naldemedine is able to produce more spontaneous bowel movements (SBMs) when compared to alvimopan and naloxegol. Tolerability was found to be similar for all of them. In particular, they affect the gastrointestinal tract (GI), with flatulence and diarrhea, especially at high dosages. For some of them, nasopharyngitis and abdominal pain were observed as treatment adverse effects (TEAs). Several cardiovascular TEAs were reported after methylnaltrexone use, but it is not clear whether they were consequences of the drug or related to the general conditions of the patients. Considering the existing data, naloxegol and naldemedine seem to be the best choices, with a higher number of spontaneous bowel movements following naldemedine administration.

Metabolically stable neurotensin analogs exert potent and long-acting analgesia without hypothermia

The endogenous tridecapeptide neurotensin (NT) has emerged as an important inhibitory modulator of pain transmission, exerting its analgesic action through the activation of the G protein-coupled receptors, NTS1 and NTS2. Whereas both NT receptors mediate the analgesic effects of NT, NTS1 activation also produces hypotension and hypothermia, which may represent obstacles for the development of new pain medications. In the present study, we implemented various chemical strategies to improve the metabolic stability of the biologically active fragment NT(8-13) and assessed their NTS1/NTS2 relative binding affinities. We then determined their ability to reduce the nociceptive behaviors in acute, tonic, and chronic pain models and to modulate blood pressure and body temperature. To this end, we synthesized a series of NT(8-13) analogs carrying a reduced amide bond at Lys⁸-Lys⁹ and harboring site-selective modifications with unnatural amino acids, such as silaproline (Sip) and trimethylsilylalanine (TMSAla). Incorporation of Sip and TMSAla respectively in positions 10 and 13 of NT(8-13) combined with the Lys⁸-Lys⁹ reduced amine bond (JMV5296) greatly prolonged the plasma half-life time over 20 h. These modifications also led to a 25-fold peptide selectivity toward NTS2. More importantly, central delivery of JMV5296 was able to induce a strong antinociceptive effect in acute (tail-flick), tonic (formalin), and chronic inflammatory (CFA) pain models without inducing hypothermia. Altogether, these results demonstrate that the chemically-modified NT(8-13) analog JMV5296 exhibits a better therapeutic profile and may thus represent a promising avenue to guide the development of new stable NT agonists and improve pain management.

"My life is under control with these medications": an interpretative phenomenological analysis of managing chronic pain with opioids

Background

The use of opioids to relieve chronic pain has increased during the last decades, but experiences of chronic opioid therapy (COT) (> 90 days) point at risks and loss of beneficial effects. Still, some patients report benefits from opioid medication, such as being able to stay at work. Guidelines for opioid use in chronic pain do not consider the individual experience of COT, including benefits and risks, making the first person perspective an important scientific component to explore. The aim of this study was to investigate the lived experience of managing chronic pain with opioids in a sample who have severe chronic pain but are able to manage their pain sufficiently to remain at work.

Methods

We used a qualitative research design: interpretative phenomenological analysis. Ten individuals with chronic pain and opioid therapy were purposively sampled in Swedish tertiary care.

Results

Three super-ordinate themes emerged from the analyses: Without opioids, the pain becomes the boss; Opioids as a salvation and a curse, and Acknowledgement of the pain and acceptance of opioid therapy enables transition to a novel self. The participants used opioids to regain control over their pain, thus reclaiming their wanted life and self, and sense of control over one’s life-world. Using opioids to manage pain was not unproblematic and some of the participants had experienced a downward spiral of escalating pain and uncontrollable opioid use, and stigmatisation.

Conclusions

All participants emphasised the importance of control, regarding both pain and opioid use. To accomplish this, trust between participants and health care providers was essential for satisfactory treatment. Regardless of the potential sociocultural benefits of staying at work, participants had experiences of balancing positive and negative effects of opioid therapy, similar to what previous qualitative research has found.

Measurable improvement of function and quality of life, may justify the long-term use of opioids in some cases. However, monitoring of adverse events should be mandatory. This requires close cooperation and a trusting relationship between the patients and their health care provider.

Cancer Screening Among Women Prescribed Opioids: A National Study

PURPOSE

Prior work suggests that there are competing demands between addressing pain and other issues in primary care, potentially lessening delivery of evidence-based cancer screening. We assessed the association between opioid therapy and cancer screening among women in a nationally representative US sample.

METHODS

We conducted an observational analysis of the 2005-2015 Medical Expenditure Panel Surveys. We included all women aged ≥18 years without cancer and with opioid prescription and preventive care services data. Logistic regression analyses examined associations between receipt of opioid prescription (any vs none) and receipt of breast, cervical, and colorectal cancer screenings. Analyses were adjusted for sociodemographic characteristics, health status, health conditions, and usual source of care, as well as health care utilization.

RESULTS

Of 53,982 participants, 15.8% reported ≥1 opioid prescription. Compared with women not prescribed opioids, those prescribed opioids were more likely to visit their doctor (median number of visits per year = 5, vs 1). Without adjustment for number of visits, women prescribed opioids were more likely to receive all 3 cancer screenings; the adjusted odds ratio for breast cancer screening was 1.26 (95% CI, 1.16-1.38), that for cervical cancer screening was 1.22 (95% CI, 1.13-1.33), and that for colorectal cancer screening was 1.22 (95% CI, 1.12-1.33). With adjustment for number of visits, adjusted odds ratios decreased (breast 1.07 [95% CI, 0.98-1.18]; cervical 1.01 [95% CI, 0.93-1.09]; colorectal 1.04 [95% CI, 0.95-1.14]).

CONCLUSIONS

In a nationally representative sample, receipt of opioid prescriptions was not associated with less recommended cancer screenings. Rather, women receiving opioids had greater adjusted odds of receiving breast, cervical, and colorectal cancer screening, although the associations were attenuated by adjusting for their more frequent office visits relative to women not receiving opioids.

Where should analgesia lead to? Quality of life and functional recovery with tapentadol

Chronic pain is a major health-care problem worldwide, affecting more than one out of five adults in Europe. Although multiple analgesic agents have been extensively investigated in terms of clinical response and tolerability profile, few studies have focused on the impact of these therapies on patients' quality of life (QoL). Of note, improvement in QoL, together with functional recovery, has been recognized since the late 1990s as two main goals of analgesic therapy. Tapentadol is a novel analgesic molecule that synergistically combines two mechanisms of action, µ-opioid receptor agonism and norepinephrine reuptake inhibition, and for which multiple literature data are available that confirm its efficacy and safety in controlling pain. This narrative review summarizes the information available on the impact of tapentadol on QoL, with the aim to provide clinicians with a comprehensive overview of the analgesic effects of tapentadol prolonged release beyond the reduction of pain.

Health-Related Quality of Life among Chronic Opioid Users, Nonchronic Opioid Users, and Nonopioid Users with Chronic Noncancer Pain

OBJECTIVE

Evaluate the association between opioid therapy and health-related quality of life (HRQoL) in participants with chronic, noncancer pain (CNCP).

DATA SOURCES

Medical Expenditure Panel Survey Longitudinal, Medical Conditions, and Prescription Files.

STUDY DESIGN

Using a retrospective cohort study design, the Mental Health Component (MCS12) and Physical Health Component (PCS12) scores of the Short Form-12 Version 2 were assessed to measure mental and physical HRQoL.

DATA COLLECTION

Chronic, noncancer pain participants were classified as chronic, nonchronic, and nonopioid users. One-to-one propensity score matching was employed to match chronic opioid users to nonchronic opioid users plus nonchronic opioid users and chronic opioid users to nonopioid users.

PRINCIPAL FINDINGS

A total of 5,876 participants were identified. After matching, PCS12 was not significantly different between nonchronic versus nonopioid users (LSM Diff = -0.98, 95% CI: -2.07, 0.10), chronic versus nonopioid users (LSM Diff = -2.24, 95% CI: -4.58, 0.10), or chronic versus nonchronic opioid users (LSM Diff = -2.23, 95% CI: -4.53, 0.05). Similarly, MCS12 was not significantly different between nonchronic versus nonopioid users (LSM Diff = 0.76, 95% CI: -0.46, 1.98), chronic versus nonopioid users (LSM Diff = 1.08, 95% CI: -1.26, 3.42), or chronic versus nonchronic opioid users (LSM Diff = -0.57, 95% CI: -2.90, 1.77).

CONCLUSIONS

Clinicians should evaluate opioid use in participants with CNCP as opioid use is not correlated with better HRQoL.

The impact of opioid analgesic prescription uptake on the costs of recovery from injury: Evidence from compensable orthopaedic road trauma patients

Long-term opioid prescribing after compensable orthopaedic injury may contribute to the 'long right tail' in the cost of recovery. The aim of this study was to estimate the effect of prescription opioid uptake on injury compensation cost, using orthopaedic road traffic injury claims data from Victoria, Australia. We used a maximum likelihood estimation that accounts for potential endogeneity associated with opioid uptake, utilizing information on the doctor's differential propensity to prescribe opioids when treating other compensable injury patients. Our results suggest that opioid recipients incurred significantly greater hospital costs, income compensation payments, and medical and paramedical expenses. Overall, income compensation was the primary driver of the claim cost difference between opioid recipients and non-recipients. The findings imply that there is scope to impose restrictions on long-term opioid usage, and to encourage the use of alternative pain relief medicines.

The impact of therapeutic opioid agonists on driving-related psychomotor skills assessed by a driving simulator or an on-road driving task: A systematic review

BACKGROUND

Driving cessation is associated with poor health-related outcomes. People with chronic diseases are often prescribed long-term opioid agonists that have the potential to impair driving. Studies evaluating the impact of opioids on driving-related psychomotor skills report contradictory results likely due to heterogeneous designs, assessment tools and study populations. A better understanding of the effects of regular therapeutic opioid agonists on driving can help to inform the balance between individual's independence and community safety.

AIM

To identify the literature assessing the impact of regular therapeutic opioid agonists on driving-related psychomotor skills for people with chronic pain or chronic breathlessness.

DESIGN

Systematic review reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis statement; PROSPERO Registration CRD42017055909.

DATA SOURCES

Six electronic databases and grey literature were systematically searched up to January, 2017. Inclusion criteria were as follows: (1) empirical studies reporting data on driving simulation, on-the-road driving tasks or driving outcomes; (2) people with chronic pain or chronic breathlessness; and (3) taking regular therapeutic opioid agonists. Critical appraisal used the National Institutes of Health's quality assessment tools.

RESULTS

From 3809 records screened, three studies matched the inclusion criteria. All reported data on people with chronic non-malignant pain. No significant impact of regular therapeutic opioid agonists on people's driving-related psychomotor skills was reported. One study reported more intense pain significantly worsened driving performance.

CONCLUSION

This systematic review does not identify impaired simulated driving performance when people take regular therapeutic opioid agonists for symptom control, although more prospective studies are needed.

Use and Misuse of Opioids in Chronic Pain

The prescribing of opioid analgesics for pain management-particularly for management of chronic noncancer pain (CNCP)-has increased more than fourfold in the United States since the mid-1990s. Yet there is mounting evidence that opioids have only limited effectiveness in the management of CNCP, and the increased availability of prescribed opioids has contributed to upsurges in opioid-related addiction cases and overdose deaths. These concerns have led to critical revisiting and modification of prior pain management practices (e.g., guidelines from the Centers for Disease Control and Prevention), but the much-needed changes in clinical practice will be facilitated by a better understanding of the pharmacology and behavioral effects of opioids that underlie both their therapeutic effects (analgesia) and their adverse effects (addiction and overdose). With these goals in mind, this review first presents an overview of the contemporary problems associated with opioid management of CNCP and the related public health issues of opioid diversion, overdose, and addiction. It then discusses the pharmacology underlying the therapeutic and main adverse effects of opioids and its implications for clinical management of CNCP within the framework of recent clinical guidelines for prescribing opioids in the management of CNCP.

Opioid-Induced Constipation and Bowel Dysfunction: A Clinical Guideline

OBJECTIVE

To formulate timely evidence-based guidelines for the management of opioid-induced bowel dysfunction.

SETTING

Constipation is a major untoward effect of opioids. Increasing prescription of opioids has correlated to increased incidence of opioid-induced constipation. However, the inhibitory effects of opioids are not confined to the colon, but also affect higher segments of the gastrointestinal tract, leading to the coining of the term "opioid-induced bowel dysfunction."

METHODS

A literature search was conducted using Medline, EMBASE, and EMBASE Classic, and the Cochrane Central Register of Controlled Trials. Predefined search terms and inclusion/exclusion criteria were used to identify and categorize relevant papers. A series of statements were formulated and justified by a comment, then labeled with the degree of agreement and their level of evidence as judged by the Strength of Recommendation Taxonomy (SORT) system.

RESULTS

From a list of 10,832 potentially relevant studies, 33 citations were identified for review. Screening the reference lists of the pertinent papers identified additional publications. Current definitions, prevalence, and mechanism of opioid-induced bowel dysfunction were reviewed, and a treatment algorithm and statements regarding patient management were developed to provide guidance on clinical best practice in the management of patients with opioid-induced constipation and opioid-induced bowel dysfunction.

CONCLUSIONS

In recent years, more insight has been gained in the pathophysiology of this "entity"; new treatment approaches have been developed, but guidelines on clinical best practice are still lacking. Current knowledge is insufficient regarding management of the opioid side effects on the upper gastrointestinal tract, but recommendations can be derived from what we know at present.

Will optogenetics be used to treat chronic pain patients?

Chronic pain affects a third of the population and current treatments produce limited relief and severe side effects. An alternative strategy to decrease pain would be to directly modulate somatosensory pathways using optogenetics. Optogenetics involves the use of genetically encoded and optically active proteins, namely opsins, to control neuronal circuits. In preclinical animal models, optical silencing of peripheral nociceptors has been shown to alleviate both inflammatory and neuropathic pain. An opsin-based gene therapy to treat chronic pain patients is not ready yet, but encouraging advances have been made in optical and viral technology. In view of the increasing burden of chronic pain in our aging society, innovative analgesic approaches based on optogenetics are definitely worth exploring.

Addressing the barriers related with opioid therapy for management of chronic pain in India

India has a high prevalence of chronic disorders which may be associated with persistent pain. Despite the availability of multiple treatment options, chronic pain is largely untreated and contributes to disability and mortality. Medical consumption of opioids remains low due to various barriers that prevent access to opioids for patients and healthcare practitioners. Stringent regulatory provisions outlined in the Narcotic Drugs and Psychotropic Substances Act (1985) have been major deterrents to adequate opioid use. Although multiple amendments to the act have ensured ease of opioid access for medicinal purposes, concerns such as lack of awareness and prescribing practices and attitudes of physicians/patients still need to be addressed. This review aims to identify these barriers and suggest recommendations to overcome them.

Palliative care for patients with end-stage liver disease

Liver disease results in over four million physician visits and over 750,000 hospitalizations per year in the USA. Those with chronic liver disease frequently progress to cirrhosis, end-stage liver disease (ESLD), and death. Patients with ESLD experience numerous complications, including muscle cramps, confusion (hepatic encephalopathy), protein calorie malnutrition, muscle wasting, fluid overload (ascites, edema), bleeding (esophagogastric variceal hemorrhage), infection (spontaneous bacterial peritonitis), fatigue, anxiety, and depression. Despite significant improvements in palliation of these complications, patients still suffer reduced quality of life and must confront the fact that their disease will often inexorably progress to death. Liver transplantation is a valid option in this setting, increasing the duration of survival and palliating many of the symptoms. However, many patients die waiting for an organ or are not candidates for transplantation due to comorbid illness. Others receive a transplant but succumb to complications of the transplant itself. Patients and families must struggle with simultaneously hoping for a cure while facing a life-threatening illness. Ideally, the combination of palliative care with life-sustaining therapy can maximize the patients' quality and quantity of life. If it becomes clear that life-sustaining therapy is no longer an option, these patients are then already in a system to help them with end-of-life care.

Opioid-induced constipation: pathophysiology, clinical consequences, and management

Although opioids offer potent analgesia for severe acute and chronic noncancer pain, adverse gastrointestinal effects potentially undermine their clinical utility. In particular, between 40% and 95% of patients develop opioid-induced constipation (OIC). Therefore, there is a consensus that patients should commence laxatives at the start of opioid therapy and continue throughout treatment. Nevertheless, laxatives are not routinely coprescribed with opioids. Even when concurrent laxatives are prescribed, approximately half the patients treated for OIC do not achieve the desired improvement. Moreover, laxatives do not target the underlying cause of OIC (opioid binding to the μ-receptors in the enteric system) and as such are not very effective at managing OIC. The failure of lifestyle modification and laxatives to treat adequately many cases of OIC led to the concurrent use of peripherally acting opioid antagonists (such as methylnaltrexone bromide and naloxone) to reduce the incidence of gastrointestinal adverse events without compromising analgesia. Judicious use of the various options to manage OIC should allow more patients to benefit from opioid analgesia. Therefore, this paper reviews the causes, consequences, and management of OIC to help clinicians optimise opioid analgesia.

Chronic pain among liver transplant candidates

CONTEXT

Little systematic research has been conducted to understand pain among persons with end-stage liver disease, especially among liver transplant candidates. Appropriate pain assessment and management are important areas of consideration as treatment options are limited.

OBJECTIVE

To describe the nature of chronic pain in patients with end-stage liver disease, the extent to which pain affects daily level of functioning, and the variety and effectiveness of current treatments.

DESIGN

Retrospective chart review.

SETTING

Academic medical center in the Southeastern United States.

PATIENTS

Data were collected from 108 consecutive adult liver transplant candidates.

RESULTS

Most (77%) reported having experienced moderate levels of bodily pain within the past 24 hours. Patients with only alcoholic cirrhosis reported less pain than patients with cirrhosis due to other causes (alcoholism and hepatitis C, nonalcoholic steatohepatitis, only hepatitis C). Pain interfered significantly across all 10 functional domains assessed. Although 90% reported being prescribed a variety of analgesic agents (most commonly short-acting opioids), patients reported experiencing only 33% pain relief.

CONCLUSIONS

Pain is a significant problem among liver transplant candidates, and current pain treatments are perceived to be relatively ineffective. Increased understanding is needed to safely and effectively evaluate and treat such medically complicated patients.

Increased anxiety-like behaviors in rats experiencing chronic inflammatory pain

For many patients, chronic pain is often accompanied, and sometimes amplified, by co-morbidities such as anxiety and depression. Although it represents important challenges, the establishment of appropriate preclinical behavioral models contributes to drug development for treating chronic inflammatory pain and associated psychopathologies. In this study, we investigated whether rats experiencing persistent inflammatory pain induced by intraplantar injection of complete Freund's adjuvant (CFA) developed anxiety-like behaviors, and whether clinically used analgesic and anxiolytic drugs were able to reverse CFA-induced anxiety-related phenotypes. These behaviors were evaluated over 28 days in both CFA- and saline-treated groups with a variety of behavioral tests. CFA-induced mechanical allodynia resulted in increased anxiety-like behaviors as evidenced by: (1) a significant decrease in percentage of time spent and number of entries in open arms of the elevated-plus maze (EPM), (2) a decrease in number of central squares visited in the open field (OF), and (3) a reduction in active social interactions in the social interaction test (SI). The number of entries in closed arms in the EPM and the distance traveled in the OF used as indicators of locomotor performance did not differ between treatments. Our results also reveal that in CFA-treated rats, acute administration of morphine (3mg/kg, s.c.) abolished tactile allodynia and anxiety-like behaviors, whereas acute administration of diazepam (1mg/kg, s.c) solely reversed anxiety-like behaviors. Therefore, pharmacological treatment of anxiety-like behaviors induced by chronic inflammatory pain can be objectively evaluated using multiple behavioral tests. Such a model could help identify/validate alternative potential targets that influence pain and cognitive dimensions of anxiety.

Chronic opioid therapy and preventive services in rural primary care: an Oregon rural practice-based research network study

PURPOSE

For clinicians, using opioid therapy for chronic noncancer pain (CNCP) often gives rise to a conflict between treating their patients' pain and fears of addiction, diversion of medication, or legal action. Consequent stresses on clinical encounters might adversely affect some elements of clinical care. We evaluated a possible association between chronic opioid therapy (COT) for CNCP and receipt of various preventive services.

METHODS

We conducted a retrospective cohort study in 7 primary care clinics within the Oregon Rural Practice-based Research Network (ORPRN). Using medical records of 704 patients, aged 35 to 85 years, seen during a 3-year period, we compared the receipt of 4 preventive services between patients on COT for CNCP and patients not on chronic opioid therapy (non-COT). We used multivariate log-binomial regression analyses to estimate the relative risk of receipt of each preventive service.

RESULTS

After adjustment for plausible confounders, we found that patients using COT had a statistically significantly lower relative risk (RR) of receipt of cervical cancer screening (RR = 0.60; 95% confidence interval [CI], 0.47-0.76) and colorectal cancer screening (RR = 0.42; 95% CI, 0.22-0.80) when compared with non-COT patients. The RR was reduced, without statistical significance, for lipid screening (RR = 0.77; 95% CI, 0.54-1.10), and not notably reduced for smoking cessation counseling (RR = 0.95; 95% CI, 0.78-1.15).

CONCLUSIONS

Patients using COT for CNCP were less likely to receive some preventive services. Research is needed to better understand barriers to and improved methods for providing preventive services for these patients.

Alleged breaches of "standards of medical care" in a patient overdose death possibly related to chronic opioid analgesic therapy, application of the controlled substances model guidelines: case report

OBJECTIVES

The objectives of this medicolegal case report are the following: 1) to present details of a chronic pain patient (CPP) who was placed on chronic opioid analgesic therapy (COAT), and subsequently overdosed on multiple drugs, some of which were not prescribed by his COAT physician; 2) to present both the plaintiff's and defendant's (the COAT prescriber) expert witnesses' opinions as to the allegation that COAT prescribing was the cause of death; and 3) based on these opinions, to develop some recommendations on how pain physicians can utilize the use of Controlled Substances Model Guidelines in order to protect the patient and themselves from such an occurrence.

METHODS

This is a case report of a CPP treated by a pain physician.

RESULTS

Differences between the plaintiff's and defendant's expert's opinions are explained utilizing the Controlled Substances Model Guidelines.

CONCLUSIONS

Some CPPs may withhold information critical to their COAT treatment. Application of the Controlled Substances Model Guidelines and the newer Federation of State Medical Boards' policy on opioid prescribing can be helpful in improving patient care and may be helpful in protecting the physician medicolegally.

Evaluation of prescription opioids using operant-based pain measures in rats

Opioids are the most effective compounds available for the relief of pain, yet there are a number of side effects that are of great concern to clinicians. For example, opioids are powerful reinforcers, and the treatment of pain using opioids could lead to the development of addiction. In addition, there is an increasing body of literature demonstrating that the repeated administration of opioids could lead to a phenomenon called opioid-induced hyperalgesia (i.e., increased sensitivity to painful stimulation). Studies examining these potential adverse effects are necessary in the development of novel analgesics. Furthermore, most studies of pain sensitivity and pain relief use reflex-based procedures to identify analgesics; however, it is argued here that operant-based procedures provide measures that are more analogous to the human condition (i.e., the mechanisms of pain are similar to those in humans) and should be useful in the assessment of novel analgesics. A series of studies examining the effects of opioids and the influence of variables such as age are discussed to demonstrate the utility of this approach.

Introduction of a self-report version of the Prescription Drug Use Questionnaire and relationship to medication agreement noncompliance

The Prescription Drug Use Questionnaire (PDUQ) is one of several published tools developed to help clinicians better identify the presence of opioid abuse or dependence in patients with chronic pain. This paper introduces a patient version of the PDUQ (PDUQp), a 31-item questionnaire derived from the items of the original tool designed for self-administration, and describes evidence for its validity and reliability in a sample of patients with chronic nonmalignant pain and on opioid therapy. Further, this study examines instances of discontinuation from opioid medication treatment related to violation of the medication agreement in this population, and the relationship of these with problematic opioid misuse behaviors, PDUQ and PDUQp scores. A sample of 135 consecutive patients with chronic nonmalignant pain was recruited from a multidisciplinary Veterans Affairs chronic pain clinic, and prospectively followed over one year of opioid therapy. Using the PDUQ as a criterion measure, moderate to good concurrent and predictive validity data for the PDUQp are presented, as well as item-by-item comparison of the two formats. Reliability data indicate moderate test stability over time. Of those patients whose opioid treatment was discontinued due to medication agreement violation-related discontinuation (MAVRD) (n=38 or 28% of sample), 40% of these (n=11) were due to specific problematic opioid misuse behaviors. Based upon specificity and sensitivity analyses, a suggested cutoff PDUQp score for predicting MAVRD is provided. This study supports the PDUQp as a useful tool for assessing and predicting problematic opioid medication use in a chronic pain patient sample.

Efficacy of opioids for chronic pain: a review of the evidence

Opioid therapy for chronic pain has been popularized over the past few decades, and a concern has arisen that the analgesic efficacy of opioids is not always maintained over prolonged courses of treatment despite dose escalation and stable pain. Considering the potentially serious adverse effects of opioids, the idea that pain relief could diminish over time may have a significant impact on the decision to embark on this therapy, especially in vulnerable individuals. Possible loss of analgesic efficacy is especially concerning, considering that dependence may make it hard to withdraw opioid therapy even in the face of poor analgesia. This article first reviews the evidence on opioid efficacy when used for the treatment of chronic pain, and concludes that existing evidence suggests that analgesic efficacy, although initially good, is not always sustained during continuous and long-term opioid therapy (months to years). The theoretical basis for loss of analgesic efficacy over time is then examined. Mechanisms for loss of analgesic efficacy proposed are pharmacologic tolerance, opioid-induced hyperalgesia, subtle and intermittent withdrawal, and a number of psychologic factors including loss of the placebo component.

Challenges in using opioids to treat pain in persons with substance use disorders

Pain and substance abuse co-occur frequently, and each can make the other more difficult to treat. A knowledge of pain and its interrelationships with addiction enhances the addiction specialist's efficacy with many patients, both in the substance abuse setting and in collaboration with pain specialists. This article discusses the neurobiology and clinical presentation of pain and its synergies with substance use disorders, presents methodical approaches to the evaluation and treatment of pain that co-occurs with substance use disorders, and provides practical guidelines for the use of opioids to treat pain in individuals with histories of addiction. The authors consider that every pain complaint deserves careful investigation and every patient in pain has a right to effective treatment.

What percentage of chronic nonmalignant pain patients exposed to chronic opioid analgesic therapy develop abuse/addiction and/or aberrant drug-related behaviors? A structured evidence-based review

DESIGN

This is a structured evidence-based review of all available studies on the development of abuse/addiction and aberrant drug-related behaviors (ADRBs) in chronic pain patients (CPPs) with nonmalignant pain on exposure to chronic opioid analgesic therapy (COAT).

OBJECTIVES

To determine what percentage of CPPs develop abuse/addiction and/or ADRBs on COAT exposure.

METHOD

Computer and manual literature searches yielded 79 references that addressed this area of study. Twelve of the studies were excluded from detailed review based on exclusion criteria important to this area. Sixty-seven studies were reviewed in detail and sorted according to whether they reported percentages of CPPs developing abuse/addiction or developing ADRBs, or percentages diagnosed with alcohol/illicit drug use as determined by urine toxicology. Study characteristics were abstracted into tabular form, and each report was characterized according to the type of study it represented based on the Agency for Health Care Policy and Research Guidelines. Each study was independently evaluated by two raters according to 12 quality criteria and a quality score calculated. Studies were not utilized in the calculations unless their quality score (utilizing both raters) was greater than 65%. Within each of the above study groupings, the total number of CPPs exposed to opioids on COAT treatment was calculated. Similarly, the total number of CPPs in each grouping demonstrating abuse/addiction, ADRBs, or alcohol/illicit drug use was also calculated. Finally, a percentage for each of these behaviors was calculated in each grouping, utilizing the total number of CPPs exposed to opioids in each grouping.

RESULTS

All 67 reports had quality scores greater than 65%. For the abuse/addiction grouping there were 24 studies with 2,507 CPPs exposed for a calculated abuse/addiction rate of 3.27%. Within this grouping for those studies that had preselected CPPs for COAT exposure for no previous or current history of abuse/addiction, the percentage of abuse/addiction was calculated at 0.19%. For the ADRB grouping, there were 17 studies with 2,466 CPPs exposed and a calculated ADRB rate of 11.5%. Within this grouping for preselected CPPs (as above), the percentage of ADRBs was calculated at 0.59%. In the urine toxicology grouping, there were five studies (15,442 CPPs exposed). Here, 20.4% of the CPPs had no prescribed opioid in urine and/or a nonprescribed opioid in urine. For five studies (1,965 CPPs exposed), illicit drugs were found in 14.5%.

CONCLUSION

The results of this evidence-based structured review indicate that COAT exposure will lead to abuse/addiction in a small percentage of CPPs, but a larger percentage will demonstrate ADRBs and illicit drug use. These percentages appear to be much less if CPPs are preselected for the absence of a current or past history of alcohol/illicit drug use or abuse/addiction.

Assessing the impact of pharmacologic intervention on the quality of life in diabetic peripheral neuropathic pain and fibromyalgia

Chronic, neuropathic pain may be secondary to myriad etiologies including diabetic peripheral neuropathy and fibromyalgia. It is a debilitating condition that imposes a significant burden on individuals and society alike. This article will review various instruments designed to assess quality of life (QoL) and key data assessing QoL of patients suffering from these diseases as well as currently available pharmacologic agents for symptomatic management. As basic and clinical science progress over the next few years, along with the introduction of novel pharmacologic agents, we anticipate greater potential for pain intervention and improvement in the quality of life of our patients.

Literacy Demands and Formatting Characteristics of Opioid Contracts in Chronic Nonmalignant Pain Management

Chronic nonmalignant pain affects a significant number of adults, with many requiring opioid medications to manage their symptoms. Although the content of typical opioid contracts (OCs) has been explored, no studies have examined the literacy demands and formatting characteristics of OCs currently used throughout the United States. We evaluated 162 English-language OCs submitted to us by current American Pain Society members residing in the United States. OCs were evaluated for reading grade level and formatting characteristics. The mean readability of OCs was at grade level 13.8 +/- 1.3 (range = 10-17), whereas the average text point size was 11.0 +/- 1.4 (range = 6-16). Active voice was used exclusively in almost half of OCs (n = 79, 48.8%). Most OCs contained not only sophisticated medical language but multisyllable, nonmedical terms and vocabulary not used in typical everyday conversation. Overall, most OCs reviewed presented information at much too high a reading grade level, and with formatting characteristics that probably would make these documents difficult for the average patient to fully comprehend.

PERSPECTIVE

This study indicates that there is a mismatch between the reading demands of most OCs and the actual health literacy skills of American adults. Accordingly, those developing OCs should be cognizant of the actual literacy abilities of their patient population and design and evaluate OCs accordingly.

Opioid-induced bowel dysfunction: prevalence, pathophysiology and burden

As a result of the undesired action of opioids on the gastrointestinal (GI) tract, patients receiving opioid medication for chronic pain often experience opioid-induced bowel dysfunction (OBD), the most common and debilitating symptom of which is constipation. Based on clinical experience and a comprehensive MEDLINE literature review, this paper provides the primary care physician with an overview of the prevalence, pathophysiology and burden of OBD. Patients with OBD suffer from a wide range of symptoms including constipation, decreased gastric emptying, abdominal cramping, spasm, bloating, delayed GI transit and the formation of hard dry stools. OBD can have a serious negative impact on quality of life (QoL) and the daily activities that patients feel able to perform. To relieve constipation associated with OBD, patients often use laxatives chronically (associated with risks) or alter/abandon their opioid medication, potentially sacrificing analgesia. Physicians should have greater appreciation of the prevalence, symptoms and burden of OBD. In light of the serious negative impact OBD can have on QoL, physicians should encourage dialogue with patients to facilitate optimal symptomatic management of the condition. There is a pressing need for new therapies that act upon the underlying mechanisms of OBD.