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Chronic pain clinical trials have historically assessed benefit and risk outcomes separately. However, a growing body of research suggests that a composite metric that accounts for benefit and risk in relation to each other can provide valuable insights into the effects of different treatments. Researchers and regulators have developed a variety of benefit-risk composite metrics, although the extent to which these methods apply to randomized clinical trials (RCTs) of chronic pain has not been evaluated in the published literature. This article was motivated by an Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials consensus meeting and is based on the expert opinion of those who attended. In addition, a review of the benefit-risk assessment tools used in published chronic pain RCTs or highlighted by key professional organizations (ie, Cochrane, European Medicines Agency, Outcome Measures in Rheumatology, and U.S. Food and Drug Administration) was completed. Overall, the review found that benefit-risk metrics are not commonly used in RCTs of chronic pain despite the availability of published methods. A primary recommendation is that composite metrics of benefit-risk should be combined at the level of the individual patient, when possible, in addition to the benefit-risk assessment at the treatment group level. Both levels of analysis (individual and group) can provide valuable insights into the relationship between benefits and risks associated with specific treatments across different patient subpopulations. The systematic assessment of benefit-risk in clinical trials has the potential to enhance the clinical meaningfulness of RCT results.

Supplemental Digital Content is Available in the Text., Although certain risk factors can identify individuals who are most likely to develop chronic pain, few interventions to prevent chronic pain have been identified. To facilitate the identification of preventive interventions, an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain. We present general design considerations for prevention trials in populations that are at relatively high risk for developing chronic pain. Specific design considerations included subject identification, timing and duration of treatment, outcomes, timing of assessment, and adjusting for risk factors in the analyses. We provide a detailed examination of 4 models of chronic pain prevention (ie, chronic postsurgical pain, postherpetic neuralgia, chronic low back pain, and painful chemotherapy-induced peripheral neuropathy). The issues discussed can, in many instances, be extrapolated to other chronic pain conditions. These examples were selected because they are representative models of primary and secondary prevention, reflect persistent pain resulting from multiple insults (ie, surgery, viral infection, injury, and toxic or noxious element exposure), and are chronically painful conditions that are treated with a range of interventions. Improvements in the design of chronic pain prevention trials could improve assay sensitivity and thus accelerate the identification of efficacious interventions. Such interventions would have the potential to reduce the prevalence of chronic pain in the population. Additionally, standardization of outcomes in prevention clinical trials will facilitate meta-analyses and systematic reviews and improve detection of preventive strategies emerging from clinical trials.

Beatrice Setnik,1 Carl L Roland,1 Kenneth W Sommerville,1,2 Glenn C Pixton,1 Robert Berke,3,4 Anne Calkins,5 Veeraindar Goli1,2 1Pfizer Inc, 2Duke University Medical Center, Durham, NC, 3Family Health Medical Services PLLC, Mayville, NY, 4Department of Social and Preventive Medicine, State University of New York at Buffalo, Buffalo, NY, 5New York Spine & Wellness Center, Syracuse, NY, USA Objective: To compare the investigator assessment of patient risk for prescription opioid misuse, abuse, and diversion with patient self-reports of these activities in a population with chronic pain. Methods: As a secondary objective of an open-label, multicenter, primary care-based clinical study to evaluate the success of converting opioid-experienced patients with chronic pain to morphine sulfate with sequestered naltrexone hydrochloride, risk for misuse, abuse, and diversion was assessed using two nonvalidated questionnaires: one was completed by the investigator and another by the patient (Self-Reported Misuse, Abuse, and Diversion [SR-MAD]). In addition, the validated Current Opioid Misuse Measure (COMM) test and urine drug test were used. Results: Of the 684 patients assessed by the investigators, 537 returned the self-assessment, SR-MAD. Most patients were assigned by the investigator as low risk for misuse (84.2%), abuse (89.3%), and diversion (94.3%). Of the patients who returned SR-MAD, 60% indicated having taken more opioids than prescribed and 10.9% reported chewing or crushing their opioids in the past. Of the patients who completed COMM, 40.6% were deemed as having aberrant behaviors. COMM results correlated with the risk levels from the investigator assessment. One-third of patients (33.8%) had at least one abnormal urine drug test result. Conclusion: More research is needed to better understand the gap between the investigator assessment of potential risk for misuse, abuse, and diversion and the actual extent of these behaviors among patients with chronic pain. Keywords: opioid, abuse, misuse, diversion, chronic pain

Objectives To compare the pharmacodynamic effects, including self-reports of “drug liking” and “high,” of crushed morphine sulfate and naltrexone hydrochloride extended-release capsules (MSN), crushed morphine sulfate controlled-release (CR) tablets, and placebo in an abuse potential study. Design Randomized, double-blind, placebo-controlled, three-way crossover study. Setting Single-center. Subjects Nondependent recreational opioid users. Interventions Orally administered crushed MSN (120-mg morphine sulfate and 4.8-mg naltrexone hydrochloride), crushed 120-mg morphine sulfate CR, and placebo. Outcome Measures Subjective ratings (100-point visual analog scales) of positive drug effects (drug liking, high, good effects, take drug again, and overall drug liking), any effects, and negative effects (bad effects, feel sick, nausea, sleepy, and dizzy), along with pupillometry, pharmacokinetic (PK), and safety assessments. Results Crushed morphine sulfate CR significantly increased ratings of all positive subjective measures relative to placebo (P

OBJECTIVE: To evaluate the pharmacodynamic (PD) effects of morphine sulfate and naltrexone hydrochloride extended-release (MSN) capsules compared with controlled-release morphine sulfate (MS) and placebo when crushed and administered intranasally.METHODS: The present study was a randomized, double-blinded, placebo-controlled, single-dose (30 mg), three-way crossover study in healthy, nondependent recreational opioid users. PD measures included assessment of subjective drug effects using visual analogue scales (VAS) ranging from 0 to 100 and assessments of pupil diameter. Blood samples were collected for pharmacokinetic analyses.RESULTS: Both MS and MSN showed significantly higher PD values compared with placebo. MSN showed significantly lower scores for drug liking and high VAS scores on both mean peak effect (Emax) (69.6 and 55.2, respectively) and in area under the effect curve over 2 h (86.3 and 66.7, respectively) following dosing compared with MS (Emax87.6 and 86.6, respectively; area under the curve over 2 h 120.6 and 132.9, respectively; Pmaxfor all other positive subjective effects (good drug effects, overall drug liking, and take drug again VAS scores) compared with MS (Pmax) and median time to Cmaxfor morphine following administration of MSN and MS were similar (27.3 ng/mL and 0.57 h versus 27.7 ng/mL and 0.6 h, respectively). Naltrexone mean Cmaxwas 1497 pg/mL after MSN and median time to Cmaxwas 0.55 h.CONCLUSIONS: When crushed and administered intranasally, MSN was associated with significantly lower ratings of drug liking and other positive subjective effects compared with MS.

Although pain reduction is commonly the primary outcome in chronic pain clinical trials, physical functioning is also important. A challenge in designing chronic pain trials to determine efficacy and effectiveness of therapies is obtaining appropriate information about the impact of an intervention on physical function. The Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) and Outcome Measures in Rheumatology (OMERACT) convened a meeting to consider assessment of physical functioning and participation in research on chronic pain. The primary purpose of this article is to synthesize evidence on the scope of physical functioning to inform work on refining physical function outcome measurement. We address issues in assessing this broad construct and provide examples of frequently used measures of relevant concepts. Investigators can assess physical functioning using patient-reported outcome (PRO), performance-based, and objective measures of activity. This article aims to provide support for the use of these measures, covering broad aspects of functioning, including work participation, social participation, and caregiver burden, which researchers should consider when designing chronic pain clinical trials. Investigators should consider the inclusion of both PROs and performance-based measures as they provide different but also important complementary information. The development and use of reliable and valid PROs and performance-based measures of physical functioning may expedite development of treatments, and standardization of these measures has the potential to facilitate comparison across studies. We provide recommendations regarding important domains to stimulate research to develop tools that are more robust, address consistency and standardization, and engage patients early in tool development.

There has been growing interest among researchers and clinicians in the role of ambivalence over emotional expression (AEE) in adjustment to chronic illness. Because of the salience of anger in chronic low back pain, this condition provides a particularly good model in which to examine the role of AEE. This study examined the relation of AEE to pain and anger in a sample of 61 patients with chronic low back pain. Patients completed standardized measures of AEE, pain, and anger. Correlational analyses showed that patients who had higher AEE scores reported higher levels of evaluative and affective pain as well as higher levels of state and trait anger and the tendency to hold in angry thoughts and feelings. Mediational analyses revealed that most of the associations between AEE and pain, and AEE and anger, were independent of one another. These findings suggest that a potentially important relationship exists between AEE and key aspects of living with persistent pain. Perspective This preliminary study suggests that there is a relation between ambivalence over emotional expression and pain and anger in patients with chronic low back pain. Patients who report greater conflict with regard to expressing emotions may be experiencing higher pain and anger.

Beatrice Setnik,1 Carl L Roland,1 Kenneth W Sommerville,1,2 Glenn C Pixton,1 Robert Berke,3,4 Anne Calkins,5 Veeraindar Goli1,2 1Pfizer Inc, 2Duke University Medical Center, Durham, NC, USA; 3Family Health Medical Services PLLC, Mayville, 4Department of Social and Preventive Medicine, State University of New York at Buffalo, Buffalo, 5New York Spine & Wellness Center, Syracuse, NY, USA Objective: To evaluate the conversion of opioid-experienced patients with chronic moderate-to-severe pain to extended-release morphine sulfate with sequestered naltrexone hydrochloride (MSN) using a standardized conversion guide. Methods: This open-label, single-arm study was conducted in 157 primary care centers in the United States. A total of 684 opioid-experienced adults with chronic moderate-to-severe pain were converted to oral administration of MSN from transdermal fentanyl and oral formulations of hydrocodone, hydromorphone, methadone, oxycodone, oxymorphone, and other morphine products using a standardized conversion guide. The primary endpoint was the percentage of patients achieving a stable MSN dose within a 6-week titration phase. Secondary endpoints included duration of time to stable dose, number of titration steps, safety and efficacy measures, and investigator assessment of conversion guide utility. Results: Of the 684 patients, 51.3% were converted to a stable dose of MSN (95% confidence interval: 47.5%, 55.1%). The mean (standard deviation) number of days to stable dose was 20 (8.94), and number of titration steps to stable dose was 2.4 (1.37). The majority of adverse events were mild/moderate and consistent with opioid therapy. Mean pain scores at stable dose decreased from baseline. Investigators were generally satisfied with the conversion guide and, in 94% of cases, reported they would use it again. Conclusion: Conversion to MSN treatment using the standardized MSN conversion guide was an attainable goal in approximately half of the population of opioid-experienced patients with chronic moderate-to-severe pain. Investigators found the guide to be a useful tool to assist conversion of opioid-experienced patients to MSN. Keywords: opioid conversion, rotation, morphine, primary care, safety, equianalgesic

Clinical observations suggest that many patients with chronic pain have difficulty forgiving persons they perceive as having unjustly offended them in some way. By using a sample of 61 patients with chronic low back pain, this study sought to determine the reliability and variability of forgiveness assessments in patients and to examine the relationship of forgiveness to pain, anger, and psychological distress. Standardized measures were used to assess patients' current levels of forgiveness, forgiveness self-efficacy, pain, anger, and psychological distress. Results showed that forgiveness-related constructs can be reliably assessed in patients with persistent pain, and that patients vary considerably along dimensions of forgiveness. Furthermore, correlational analyses showed that patients who had higher scores on forgiveness-related variables reported lower levels of pain, anger, and psychological distress. Additional analyses indicated that state anger largely mediated the association between forgiveness and psychological distress, as well as some of the associations between forgiveness and pain. These findings indicate that forgiveness can be reliably assessed in patients with persistent pain, and that a relationship appears to exist between forgiveness and important aspects of living with persistent pain.This preliminary study suggests there is a relationship between forgiveness and pain, anger, and psychological distress in patients with chronic low back pain. Patients who report an inability to forgive others might be experiencing higher pain and psychological distress that are mediated by relatively higher levels of state anger.

Differentiating somatic from emotional influences on the experience of chronic pain has been of interest to clinicians and researchers for many years. Although prior research has not well specified these pathways at the anatomical level, some evidence, both theoretical and empirical, suggest that emotional reactions influence the experience of disease and non-disease-related pains. Other studies suggest that treatments directed at negative emotional responses reduce suffering associated with pain. The current study was conducted to explore the influence of emotional reactions to pain as a predictor of psychological distress in a sample of adult Blacks with Sickle Cell Disease (SCD). Using cross-sectional survey data, we evaluated whether negative emotional reactions to the experience of pain were predictive of psychological distress after controlling for the somatic dimension of pain and age in n = 67 Black patients with Sickle Cell Disease (SCD). Results showed that greater negative emotion associated with pain predicted Somatization ( p < .01), Anxiety ( p < .05), Phobic Anxiety ( p < .05), and Psychoticism ( p < .05). Increased negative emotion associated with pain was also predictive of the General Symptoms Index ( p < .05) and the Positive Symptoms Total from the SCL-90-R ( p < .01). We believe the current study demonstrates that negative emotional reactions to the experience of pain in adults with SCD are predictive of psychological distress above and beyond the influences of age and the direct nociceptive experience. We also believe these data to be valuable in conceptualizing the allocation of treatment resources toward a proactive approach with early identification of patients who are responding poorly for the purpose of potentially reducing later psychopathology. A deeper understanding of the ways that subpopulations cope with chronic disease-related pain may produce models that can be ultimately generalized to the consumers of the majority of healthcare resources.

Purpose A diazepam auto‐injector (AI) has been developed for intramuscular administration to treat acute repetitive seizures (ARS). The objective of this study was to evaluate the efficacy and safety of the diazepam AI when administered by caregivers to control an episode of ARS (ClinicalTrials.gov identifier NCT00319501). Methods In this phase III, randomized, double‐blind, parallel‐group, placebo‐controlled, multicenter study, subjects with epilepsy on a stable antiepileptic drug regimen who required intermittent medical intervention to control ARS were randomized 1:1 to the placebo AI or the diazepam AI group. Subjects were stratified according to age (2–5, 6–11, ≥12 years). Dose (5, 10, 15, or 20 mg) was based on age and weight. A single dose of study medication was dispensed to be administered by caregivers in an outpatient setting when required. The primary end point was time to next seizure or rescue from 15 min to 12 h postdose. Secondary end points included rescue medication use, number of seizures postdose, caregiver and physician treatment assessments, and safety measures. Key findings Of 234 subjects randomized, 81/110 in the placebo AI group and 82/124 in the diazepam AI group were included in the intent‐to‐treat analysis. Baseline characteristics were similar for both groups. Time to next seizure or rescue was significantly longer in the diazepam AI group compared with the placebo AI group, with a hazard ratio of 0.55 (95% confidence interval [CI] 0.34–0.88; p = 0.012) for diazepam AI versus placebo AI, adjusted for age group. The 25th percentile for time to the next seizure or rescue was 1.18 h (95% CI 0.38–2.03) for placebo AI and 2.70 h (95% CI 0.48–11.42) for diazepam AI; the median was 5.9 h for placebo AI and was inestimable for diazepam AI due to the low number of events experienced by subjects in that group. The proportion of subjects using rescue medication postdose was 30% (24/81) placebo AI versus 17% (14/82) diazepam AI (p = 0.066). An event (seizure or rescue) occurred in 55.6% of subjects in the placebo AI group and 35.4% in the diazepam AI group. The number of seizures experienced during the 12‐h postdose period was significantly lower for diazepam AI (median 0.0) compared with placebo AI (median 1.0; p = 0.010). Treatment‐emergent adverse events (TEAEs) were reported in 44% (35/79) of subjects in the placebo AI group and 42% (34/81) in the diazepam AI group. The most common TEAEs reported were injection site pain (15% placebo AI, 17% diazepam AI) and injection site hemorrhage (6% placebo AI, 5% diazepam AI). Significance The diazepam AI was significantly more effective than placebo AI at delaying the next seizure or rescue. Secondary efficacy end points were generally supportive of the primary outcome. Diazepam AI administered by trained caregivers was effective for the treatment of ARS and was well tolerated, with a safety profile similar to placebo.

Background Respiratory depression, a potentially fatal side-effect of opioid-overdose, may be reversed by timely administration of an opioid antagonist, such as naloxone or naltrexone. Tampering with a formulation of morphine sulfate and sequestered naltrexone hydrochloride extended release capsules (MS-sNT) releases both the opioid morphine and the antagonist naltrexone. A study in recreational opioid-users indicated that morphine and naltrexone injected in the 25:1 ratio (duplicating the ratio of the formulation) found MS-sNT reduced morphine-induced euphoric effects vs intravenous (IV) morphine alone. In the same study, the effects of morphine + naltrexone on end-tidal carbon dioxide (EtCO2), a measure of respiratory-depression, were evaluated and these data are reported here. Methods Single-center, placebo-controlled, double-blind crossover study. Non-dependent male opioid users were randomized to receive single IV doses of placebo, 30 mg morphine alone, and 30 mg morphine + 1.2 mg naltrexone. EtCO2 was measured by noninvasive capnography. Results Significant differences in EtCO2 least-squares means across all treatments for maximal effect (Emax) and area under the effect curve (AUE0-2, AUE0-8, AUE0-24) were detected (all p ≤ 0.0011). EtCO2 Emax values for morphine + naltrexone were significantly reduced vs morphine alone (42.9 mm Hg vs 47.1 mm Hg, p < 0.0001) and were not significantly different vs placebo (41.9 mm Hg). Median time to reach maximal effect (TEmax) was delayed for morphine + naltrexone vs morphine alone (5.0 h vs 1.0 h). Conclusions Results provide preliminary evidence that the naltrexone:morphine ratio within MS-sNT is sufficient to significantly reduce EtCO2 when administered intravenously to non-dependent male recreational opioid-users. Further studies with multiple measures of respiratory-function are warranted to determine if risk of respiratory depression is also reduced by naltrexone in the tampered formulation.