Nonopioid Medications for Pain

Experience of compassion-based practice in mindfulness for health for individuals with persistent pain

Purpose of the Study

Research indicates that acquiring compassion is an integral part to positive outcomes to Mindfulness-based interventions (MBI), yet there is both theoretic and empirical literature suggesting that people with persistent pain are more likely to experience challenges and distress when engaging compassion-based practices. Mindfulness for Health is a standardised MBI for people with persistent pain and health conditions. This study sought to explore the positive, neutral and difficult experiences of compassion-based practice and meditation for participants in Mindfulness for Health to further understand implications and risks for participants of MBI's.

Method and Design

A qualitative design using Interpretative Phenomenological Analysis was applied to explore how participants understood of the experience of compassion-based practice and the meaning they gave to it. Eight participants who had completed the Mindfulness for Health from four separate groups were interviewed about their experience.

Results

Five master themes were identified 'turning away from self-with-pain', 'self-with-pain experienced as shameful', 'facilitating change', 'turning towards self-with-pain', and 'accepting self'. Participants identified both perceived positive changes and difficult emotional experiences during the meditation practice, which they related to the context of compassion in their past and present life.

Conclusions

Developing compassion is an important part of Mindfulness for Health, which is salient for participants as both a challenging and potentially valuable experience. Acquisition of mindfulness skills, supporting group dynamics and modelling compassion are understood as helpful in overcoming personal barriers and challenging experiences. Further research is needed to understand processes involved and explore the experience of non-completers.

Symptom Management in the Older Adult: 2023 Update

In the older adult with a serious illness, the goal of palliative medicine and symptom management is to optimize quality of life. Frailty has become an overarching finding in many older adults with serious illness. Symptom management options need to be considered in the lens of increasing frailty along an illness trajectory. Here, the authors emphasize literature updates and best practices for the most common symptoms experienced by the older adult with a serious illness.

Novel Therapies for Centralized Pain: a Brief Review

PURPOSE OF REVIEW

Centralized pain presents a complex pathology that many classic pharmacological agents for pain have not been able to sufficiently treat. To date, there are no clear guidelines for preferred treatment methods or comprehensive protocol that addresses confounding factors in this population. We sought to summarize the current field of knowledge around centrally mediated pain and to understand promising novel therapies.

RECENT FINDINGS

Many treatments currently used address not only the centralized pain phenotypem but the impact of central sensitization and the common comorbidities that reside within this population. Some novel therapies with promising evidence include the following: low-dose naltrexone, IV ketamine, acupuncture, aerobic activity, and laser therapy. Non-interventional treatment options include aerobic exercise, cognitive-behavioral therapy, mind-body therapies, virtual reality, and patient education on disease expectations. Much of the literature further emphasizes the importance of patient-level predictors, including factors like pain catastrophizing and social history, on treatment compliance and reported pain relief. We found that there are many potential treatment options for patients with centralized pain, particularly those that can be used as adjunct or combination therapies. The introduction of new approaches should occur in a carefully controlled, titrated manner to avoid exacerbation of pain symptoms. This is successfully conducted through patient-physician communication as this is a highly complex and personalized pain category. Our examination shows that while physicians have many options with proven success, there is a need for studies with longitudinal and larger patient populations to better articulate treatment guidelines.

Systematic Review of Voltage-Gated Calcium Channel α2δ Subunit Ligands for the Treatment of Chronic Neuropathic Pain and Insight into Structure-Activity Relationship (SAR) by Pharmacophore Modeling

BACKGROUND

Neuropathic pain (NP) is a complex symptom related to the nerve damage. The discovery of new drugs for treating chronic NP has been continuing for several decades, while more progress is still needed to be made because of the unsatisfactory efficacy and the side effects of the currently available drugs. Among all the approved drugs for chronic NP, voltage-gated calcium channel (VGCC) α2δ subunit ligands, also known as gabapentinoids, are among the first-line treatment and represent a class of efficacious and relatively safe therapeutic agents. However, new strategies are still needed to be explored due to the unsatisfied response rate.

OBJECTIVES

To review the latest status of the discovery and development of gabapentinoids for the treatment of chronic NP by covering both the marketed and the preclinical/clinical ones. To analyze the structure-activity relationship (SAR) of gabapentinoids to facilitate the future design of structurally novel therapeutic agents targeting VGCC α2δ subunit.

METHODS

We searched PubMed Central, Embase, Cochrane Library, Web of Science, Scopus and Espacenet for the literature and patents of diabetic peripheral neuropathic pain, postherpetic neuralgia, fibromyalgia, voltage-gated calcium channel α2δ subunit and related therapeutic agents from incipient to June 10, 2021. The SAR of gabapentinoids were analyzed by pharmacophore modeling using Phase module in Schrödinger suite.

RESULTS

A variety of gabapentinoids were identified as VGCC α2δ ligands that have ever been under development for the treatment of chronic NP. Among them, four gabapentinoids are marketed, one is at the active late clinical trials, and eight have been discontinued. Pharmacophore models were generated by using Phase module in Schrödinger suite, and common pharmacophores were predicted based on pharmacophoric features and analyzed.

CONCLUSION

The latest progress of the discovery and development of gabapentinoids for the treatment of chronic NP was reviewed. Moreover, the structure-activity relationship (SAR) of gabapentinoids is analyzed by pharmacophore modeling, which will be valuable for the future design of structurally novel therapeutic agents targeting VGCC α2δ subunit.

Feline Neuropathic Pain

Neuropathic pain represents the extreme in maladaptive pain processing. In itself, it is a disease in which pain has become exaggerated in some combination of scope, severity, character, field, duration, and spontaneity. It is almost certainly an underappreciated, underdiagnosed cause of possible significant patient morbidity in cats. This article explores the basic mechanisms, recognition, known and suspect syndromes, and prospective treatment of feline maladaptive and neuropathic pain.

A MAPP Network Case-control Study of Urological Chronic Pelvic Pain Compared With Nonurological Pain Conditions

OBJECTIVES

Limited research suggests commonalities between urological chronic pelvic pain syndromes (UCPPS) and other nonurological chronic overlapping pain conditions (COPCs) including fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome. The goal of this case-control study was to examine similarities and differences between UCPPS and these other COPCs.

MATERIALS AND METHODS

As part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research (MAPP) Network, we examined 1039 individuals with UCPPS (n=424), nonurological COPCs (n=200), and healthy controls (HCs; n=415). Validated standardized measures were used to assess urological symptoms, nonurological pain symptoms, and psychosocial symptoms and traits.

RESULTS

Participants with UCPPS had more urological symptoms than nonurological COPCs or HCs (P<0.001); nonurological COPC group also had significantly worse urological symptoms than HCs (P<0.001). Participants with nonurological COPCs reported more widespread pain than those with UCPPS (P<0.001), yet both groups had similarly increased symptoms of anxiety, depression, negative affect, perceived stress, neuroticism, and lower levels of extraversion than HCs (P<0.001). Participants with UCPPS with and without COPCs reported more catastrophizing than those with nonurological COPCs (P<0.001).

DISCUSSION

Findings are consistent with the hypothesis of common underlying biopsychosocial mechanisms and can guide the comprehensive assessment and treatment of these conditions regardless of the primary site of pain or diagnosis. Heightened catastrophizing in UCPPS should be examined to inform psychosocial interventions and improve patient care.

Compounded Topical Pain Creams to Treat Localized Chronic Pain: A Randomized Controlled Trial

BACKGROUND

The use of compounded topical pain creams has increased dramatically, yet their effectiveness has not been well evaluated.

OBJECTIVE

To determine the efficacy of compounded creams for chronic pain.

DESIGN

Randomized controlled trials of 3 interventions. (ClinicalTrials.gov: NCT02497066).

SETTING

Military treatment facility.

PARTICIPANTS

399 patients with localized pain classified by each patient's treating physician as neuropathic (n = 133), nociceptive (n = 133), or mixed (n = 133).

INTERVENTION

Pain creams compounded for neuropathic pain (ketamine, gabapentin, clonidine, and lidocaine), nociceptive pain (ketoprofen, baclofen, cyclobenzaprine, and lidocaine), or mixed pain (ketamine, gabapentin, diclofenac, baclofen, cyclobenzaprine, and lidocaine), or placebo.

MEASUREMENTS

The primary outcome measure was average pain score 1 month after treatment. A positive categorical response was a reduction in pain score of 2 or more points coupled with a score above 3 on a 5-point satisfaction scale. Secondary outcomes included Short Form-36 Health Survey scores, satisfaction, and categorical response. Participants with a positive outcome were followed through 3 months.

RESULTS

For the primary outcome, no differences were found in the mean reduction in average pain scores between the treatment and control groups for patients with neuropathic pain (-0.1 points [95% CI, -0.8 to 0.5 points]), nociceptive pain (-0.3 points [CI, -0.9 to 0.2 points]), or mixed pain (-0.3 points [CI, -0.9 to 0.2 points]), or for all patients (-0.3 points [CI, -0.6 to 0.1 points]). At 1 month, 72 participants (36%) in the treatment groups and 54 (28%) in the control group had a positive outcome (risk difference, 8% [CI, -1% to 17%]).

LIMITATIONS

Generalizability is limited by heterogeneity among pain conditions and formulations of the study interventions. Randomized follow-up was only 1 month.

CONCLUSION

Compounded pain creams were not better than placebo creams, and their higher costs compared with approved compounds should curtail routine use.

PRIMARY FUNDING SOURCE

Centers for Rehabilitation Sciences Research, Defense Health Agency, U.S. Department of Defense.

Neuroanatomical characterization of imidazoline I2 receptor agonist-induced antinociception

Chronic pain is a significant public health problem with a lack of safe and effective analgesics. The imidazoline I₂ receptor (I₂ R) is a promising analgesic target, but the neuroanatomical structures involved in mediating I₂ R-associated behaviors are unknown. I₂ Rs are enriched in the arcuate nucleus, dorsal raphe (DR), interpeduncular nucleus, lateral mammillary body, medial habenula, nucleus accumbens (NAc) and paraventricular nucleus; thus, this study investigated the antinociceptive and hypothermic effects of microinjections of the I₂ R agonist 2-(2-benzofuranyl)-2-imidazoline hydrochloride (2-BFI). In rats, intra-DR microinjections produced antinociception in complete Freund's adjuvant- and chronic constriction injury-induced pain models. Intra-NAc microinjections produced antinociception and increased noxious stimulus-associated side time in a place escape/avoidance paradigm. Intra-NAc pretreatment with the I₂ R antagonist idazoxan but not the D1 receptor antagonist SCH23390 or the D2 receptor antagonist raclopride attenuated intra-NAc 2-BFI-induced antinociception. Intra-NAc idazoxan did not attenuate systemically administered 2-BFI-induced antinociception. Microinjections into the other regions did not produce antinociception, and in none of the regions produced hypothermia. These data suggest that I₂ R activation in some but not all I₂ R-enriched brain regions is sufficient to produce antinociception and supports the theory that different I₂ R-associated effects are mediated via distinct receptor populations, which may in turn be distributed differentially throughout the CNS.

A systematic review of the effectiveness of policies restricting access to pregabalin

BACKGROUND

Formularies often employ restriction policies to reduce pharmacy costs. Pregabalin, an alpha-2-delta ligand, is approved for treatment of fibromyalgia (FM); neuropathic pain (NeP) due to postherpetic neuralgia (PHN), diabetic peripheral neuropathy (pDPN), spinal cord injury; and as adjunct therapy for partial onset seizures. Pregabalin is endorsed as first-line therapy for these indications by several US and EU medical professional societies. However, restriction policies such as prior authorization (PA) and step therapy (ST) often favor less costly generic pain medications over pregabalin.

METHODS

A structured literature search (PubMed, past 11 years) was conducted to evaluate whether restriction policies against pregabalin support real-world economic and healthcare utilization benefits.

RESULTS

Search criteria identified three claims analyses and a modeling study that evaluated patients with NeP and/or FM with and without PA restrictions; three other studies included patients with FM and NeP in plans with ST requirements, and one evaluated a mail order requirement program. All studies evaluated outcomes during follow-up periods of 6 months or longer. Overall, PA, ST, and mail order restriction policies effectively reduced pregabalin usage, but the effects were inconsistent with reducing pharmacy costs and were non-significant for total disease-related medical costs. Two studies (one PA; one ST) reported significantly higher disease-related costs in restricted plans. The modeling study failed to demonstrate cost savings with PA. Opioid usage was higher in PA-restricted plans (two studies). The US Centers for Disease Control and Prevention and several professional NeP guidelines recommend opioid use only in cases when other non-opioid pain therapies have proven ineffective. New US Government taskforce guidelines now seek to reduce opioid exposure. Additionally, in both ST studies, gabapentin utilization (a common ST edit) was significantly increased. Both studies had substantial proportions of FM and pDPN patients and the only pain condition gabapentin is approved to treat in the United States is PHN.

CONCLUSION

PA and ST restriction policies significantly decrease utilization of pregabalin, but do not consistently demonstrate cost savings for US health plans. More research is needed to evaluate whether these policies may lead to increased opioid usage as found in some studies.

TRIAL REGISTRATION

N/A.

Difficulties with assessment and management of an infant's distress in the postoperative period: Optimising opportunities for interdisciplinary information-sharing

OBJECTIVES

The importance of accurate paediatric patient assessment is well established but under-utilised in managing postoperative medication regimens.

METHODS

Data for this case report were collected through observations of clinical practice, conduct of interviews, and retrieval of information from the medical record. This case report involving a hospitalised 1-year-old boy demonstrates the difficulties associated with assessing and managing postoperative distress, including pain and other clinical conditions related to the surgical procedure.

RESULTS

Postoperatively, there were difficulties in managing pain and an episode of over-sedation, occasioning opiate reversal with naloxone. In addition, he had decreasing oxygen saturation and increased work of breathing. X-ray showed changes consistent with either atelectasis or aspiration, and he was commenced on antibiotics. The patient experienced respiratory distress and required intervention from the medical emergency team.

CONCLUSION

This case demonstrated the importance of comprehensive assessment and careful consideration of alternative causes of an infant's distress using the results of assessment tools to aid decision-making. Communication moderates effective patient care, and more favourable outcomes could be achieved by optimising interdisciplinary information-sharing.

Interactions between imidazoline I2 receptor ligands and acetaminophen in adult male rats: antinociception and schedule-controlled responding

RATIONALE

Recent evidence suggests that imidazoline I2 receptor ligands are suitable for combination therapy with opioids. Quantitative analysis of I2 receptor ligands combined with non-opioid drugs is necessary for the justification of alternative pain therapies.

OBJECTIVE

This study systematically examined the antihyperalgesic and response rate-suppressing effects of selective I2 receptor ligands (2-BFI and phenyzoline) alone and in combination with acetaminophen.

METHODS

Von Frey and Hargreaves tests were used to examine the antihyperalgesic effects of drugs in complete Freund's adjuvant (CFA)-induced inflammatory pain in rats. Food-reinforced schedule-controlled responding was used to assess the rate-suppressing effects of study drugs. Dose-addition and isobolographic analyses were used to assess drug-drug interactions for all assays.

RESULTS

2-BFI (3.2-17.8 mg/kg, i.p.), phenyzoline (17.8-100 mg/kg, i.p.), and acetaminophen (56-178 mg/kg, i.p.) all dose-dependently produced significant antinociceptive effects. When studied as combinations, 2-BFI and acetaminophen produced infra-additive to additive interactions while phenyzoline and acetaminophen produced additive to supra-additive interactions. The same drug combinations suppressed response rate in a supra-additive manner.

CONCLUSIONS

Quantitative analysis of the antihyperalgesic and response rate-suppressing effects suggests that I2 receptor ligands are not well suited to combination therapy with acetaminophen.

Managing Neuropathic Pain in Dogs

Disorders of the somatosensory system such as neuropathic pain are common in people with chronic neurologic and musculoskeletal diseases, yet these conditions remain an underappreciated morbidity in veterinary patients. This is likely because assessment of neuropathic pain in people relies heavily on self-reporting, something our veterinary patients are not able to do. The development of neuropathic pain is a complex phenomenon, and concepts related to it are frequently not addressed in the standard veterinary medical curriculum such that veterinarians may not recognize this as a potential problem in patients. The goals of this review are to discuss basic concepts in the pathophysiology of neuropathic pain, provide definitions for common clinical terms used in association with the condition, and discuss pharmacological treatment options for dogs with neuropathic pain. The development of neuropathic pain involves key mechanisms such as ectopic afferent nerve activity, peripheral sensitization, central sensitization, impaired inhibitory modulation, and pathologic activation of microglia. Treatments aimed at reducing neuropathic pain are targeted at one or more of these mechanisms. Several drugs are commonly used in the veterinary clinical setting to treat neuropathic pain. These include gabapentin, pregabalin, amantadine, and amitriptyline. Proposed mechanisms of action for each drug, and known pharmacokinetic profiles in dogs are discussed. Strong evidence exists in the human literature for the utility of most of these treatments, but clinical veterinary-specific literature is currently limited. Future studies should focus on objective methods to document neuropathic pain and monitor response to therapy in veterinary patients.