Less Well-Known Consequences of the Long-Term Use of Opioid Analgesics: A Comprehensive Literature Review

Opioid-induced androgen deficiency in men: Prevalence, pathophysiology, and efficacy of testosterone therapy

BACKGROUND

Opioid analgesics are frequently prescribed for the treatment of chronic pain and are a common cause of male androgen deficiency. Despite its high prevalence, this adverse effect of chronic opioid use remains underappreciated by clinicians. As a result, androgen deficiency remains underdiagnosed and likely undertreated. This focused review discusses the expanding literature on opioid-induced androgen deficiency and the efficacy of testosterone therapy, with a particular focus on its anti-nociceptive effects.

METHODS

Original and review articles on opioid-induced male androgen deficiency published from 1950 through June 2024 were retrieved from PubMed using the key terms "opioids," "hypogonadism," "low testosterone," and "testosterone therapy." References within the retrieved publications were also researched.

RESULTS

Opioids suppress the gonadal axis mainly by inhibiting GnRH synthesis and secretion. The prevalence of opioid-induced androgen deficiency in men varies between 20% and 80% and is influenced by the type of opioid used, duration of exposure, age of the cohort, and how low testosterone was defined. Limited data from clinical trials suggest that testosterone therapy improves libido, body composition, and certain domains of quality of life. Early evidence also suggests that testosterone has anti-nociceptive properties, confirming findings from preclinical and population studies.

CONCLUSION

Chronic opioid use is a common but underappreciated cause of androgen deficiency in men. There is a need to raise awareness among clinicians regarding this adverse effect of opioid use. Testosterone therapy could be considered in men with unequivocal androgen deficiency after a thorough clinical evaluation. Ongoing clinical trials will shed further light on the efficacy of testosterone therapy, particularly regarding its anti-nociceptive effects.

Cannabinoids in Chronic Pain Management: A Review of the History, Efficacy, Applications, and Risks

Background/Objectives: Chronic pain remains a pervasive and challenging public health issue, often resistant to conventional treatments such as opioids, which carry substantial risks of dependency and adverse effects. Cannabinoids, bioactive compounds derived from the Cannabis sativa plant and their synthetic analogs, have emerged as a potential alternative for pain management, leveraging their interaction with the endocannabinoid system to modulate pain and inflammation. Methods: The current, evolving literature regarding the history, efficacy, applications, and safety of cannabinoids in the treatment of chronic pain was reviewed and summarized to provide the most current review of cannabinoids. Results: Evidence suggests that cannabinoids provide moderate efficacy in managing neuropathic pain, fibromyalgia, cancer-related pain, and multiple sclerosis-related spasticity. Patient-reported outcomes further indicate widespread perceptions of cannabinoids as a safer alternative to opioids, with potential opioid-sparing effects. However, the quality of existing evidence is limited by small sample sizes and methodological inconsistencies. Regulatory barriers, including the classification of cannabis as a Schedule I substance in the United States, continue to hinder robust research and clinical integration. Moreover, the risks associated with cannabinoids, such as psychiatric effects, addiction potential, and drug interactions, necessitate cautious application. Conclusions: Cannabinoids represent a promising, albeit complex, alternative for chronic pain management, particularly given the limitations and risks of traditional therapies such as opioids. However, significant deficiencies remain in the research. While smaller trials and systematic reviews indicate therapeutic potential, the quality of evidence is often low due to limited sample sizes, short study durations, and methodological inconsistencies. Large-scale, randomized controlled trials with long-term follow-up are urgently needed to confirm efficacy and safety across diverse patient populations and pain etiologies.

Analgesia Nociception Index Monitoring in Management of Perioperative Analgesia in Total Knee Arthroplasty Surgeries with Femoral Nerve Block

Background and Objectives: The aim of our study is to determine the effects of analgesia nociception index (ANI) monitoring on intraoperative opioid consumption, postoperative analgesia, and the recovery unit length of stay in patients with a preoperative femoral nerve block (FNB) undergoing total knee arthroplasty (TKA) surgery under general anesthesia. Materials and Methods: Seventy-four patients in the American Society of Anesthesiologists Physical Status (ASA-PS) I-III scheduled for TKA under general anesthesia were included in this study. After FNB, the patients were divided into two groups (control group (n = 35)-ANI group (n = 35)). After standard anesthesia induction in both groups, maintenance was conducted using sevoflurane and remifentanil infusion with a bispectral index (BIS) between 40 and 60. In the control group, the intraoperative remifentanil infusion dose was adjusted using conventional methods, and in the ANI group, the dose was adjusted using ANI values of 50-70. The duration of operation, duration of surgery, extubation time, tourniquet duration and pressure, and the amount of remifentanil consumed intraoperatively were recorded. Results: Intraoperative remifentanil consumption was lower in the ANI group compared to the control group (p = 0.001). The time to reach a Modified Aldrete Scale score (MAS) ≥ 9 was shorter in the ANI group (p < 0.001). NRS scores in the recovery unit and 4, 8, 12, and 24 h postoperatively were lower in the ANI group compared to the control group (p = 0.006, p < 0.05). There was a weak significant inverse relationship between the last ANI values measured before extubation and NRS scores in the postoperative recovery unit (r: -0.070-0.079, p: 0.698-0.661). No difference was observed between the groups in other data. Conclusions: In patients undergoing TKA with FNB under general anesthesia, ANI monitoring decreased the amount of opioids consumed intraoperatively and postoperative pain scores and shortened the length of stay in the recovery unit. We suggest that ANI monitoring in intraoperative analgesia management may be helpful in determining the dose of opioid needed by the patient and individualized analgesia management.

The effects of opioid tapering on select endocrine measures in men and women with head and neck cancer-a longitudinal 12-month study

Introduction

Opioid treatment may affect endocrine measures in humans either through centrally or peripherally mediated mechanisms. There is a general lack of longitudinal studies examining endocrine measures in opioid-treated patients.

Objectives

To longitudinally follow the levels of select endocrine measures in men and women with head and neck cancer for 1 year, who after having completed radiotherapy began tapering opioids.

Methods

This was a prospective, longitudinal, observational study. Testosterone and estradiol were measured in men and women, respectively. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), dehydroepiandrosterone sulfate (DHEAS), and prolactin were measured in both sexes. Women were grouped based on if premenopausal or postmenopausal. Samples were collected when opioid tapering started and at 1, 3, 6, and 12 months after tapering start. Daily opioid doses at the same time points were registered.

Results

Twenty-five men and 12 women were followed for 12 months. In men, testosterone levels increased significantly during the first month after opioid tapering started (P < 0.001). Levels of testosterone, FSH, DHEAS, and prolactin changed significantly in men during the study period. A moderate correlation between opioid dose reduction and testosterone level increase in men aged ≤60 years was found (r s = -0.577, 95% CI -0.854 to -0.044, P = 0.039). In postmenopausal women (n = 10), levels of FSH and LH changed significantly during the study period.

Conclusion

Previously known effects of opioids on endocrine measures in humans seem to be reversible as select endocrine measures changed significantly in men and postmenopausal women after opioid tapering was initiated.

In vivo screening of flavonoid compounds revealed quercetin as a potential drug to improve recovery of angiostrongyliasis after albendazole treatment

Human angiostrongyliasis, caused by consuming the larva stage of Angiostrongylus cantonensis, is an infectious disease involving the central nervous system (CNS) and ophthalmic system. Current treatment of angiostrongyliasis involves albendazole accompanied by analgesics and corticosteroids. However, long-term use of corticosteroids may lead to significant adverse effects. In the current study, we screened through different potentially effective flavonoid compounds and identified quercetin as an effective anti-inflammatory agent in an angiostrongyliasis mouse model. Our results identified that quercetin may reverse the neurological defects in mice with angiostrongyliasis. The brain pathology and inflammatory status were also improved by albendazole-quercetin co-therapy. Further analysis showed that albendazole-quercetin co-therapy had a better therapeutic effect than albendazole or quercetin monotherapy. This therapeutic effect was achieved by inhibiting the brain inflammasome activation and apoptosis. Albendazole-quercetin co-therapy also leads to the inhibition of brain IL-5, possibly leading to improved pathology. Our results here proved that quercetin may serve as a potential adjuvant drug in treating human angiostrongyliasis.

A Review of Current Approaches to Pain Management in Knee Osteoarthritis with a Focus on Italian Clinical Landscape

The global cases of knee osteoarthritis (KOA) are projected to increase by 74.9% by 2050. Currently, over half of patients remain dissatisfied with their pain relief. This review addresses unmet needs for moderate-to-severe KOA pain; it offers evidence and insights for improved management. Italian experts from the fields of rheumatology, physical medicine and rehabilitation, orthopedics, primary care, and pain therapy have identified several key issues. They emphasized the need for standardized care protocols to address inconsistencies in patient management across different specialties. Early diagnosis is crucial, as cartilage responds better to early protective and structural therapies. Faster access to physiatrist evaluation and reimbursement for physical, rehabilitative, and pharmacological treatments, including intra-articular (IA) therapy, could reduce access disparities. Concerns surround the adverse effects of oral pharmacological treatments, highlighting the need for safer alternatives. Patient satisfaction with corticosteroids and hyaluronic acid-based IA therapies reduces over time and there is no consensus on the optimal IA therapy protocol. Surgery should be reserved for severe symptoms and radiographic KOA evidence, as chronic pain post-surgery poses significant societal and economic burdens. The experts advocate for a multidisciplinary approach, promoting interaction and collaboration between specialists and general practitioners, to enhance KOA care and treatment consistency in Italy.

Trajectories of opioid use among patients with low back pain: Association to work absence

BACKGROUND

Low back pain (LBP) is a leading reason for opioid use and a closer examination of opioid use and productivity losses among these patients is needed. We identify opioid use trajectories using a group-based trajectory model (GBTM) and estimate productivity losses across the trajectories.

METHODS

Patients diagnosed with LBP in Swedish specialty care between 2011 and 2015, between the ages of 20 and 60, were included. Two GBTMs were estimated on monthly opioid use (converted to oral morphine equivalents) during the two 12-month periods preceding and following diagnosis. Productivity losses were estimated using the human-capital approach.

RESULTS

In total, 147,035 patients were included. The mean age at diagnosis was 43 years of age and 49% of the patients were male. A qualitative assessment of the identified groups in the GBTM models was made based on the patterns of opioid use. We chose three pre-diagnosis groups characterized as 'Pre-low' (N = 109,492), 'Pre-increase' (N = 27,336) and 'Pre-high' (N = 10,207). Similarly, four post-diagnosis groups were chosen and characterized as 'Post-low' (N = 73,287), 'Post-decrease' (N = 39,446), 'Post-moderate' (N = 20,001) and 'Post-high' (N = 13,595). Only 50% of the patients in the 'Pre-high' group were in the 'Post-high' group. The total productivity losses by the pre-diagnosis groups were more than 2.7 billion Euros over the total 6-year study period.

CONCLUSION

This study highlights how patients with LBP and high use of opioids are highly correlated before and after diagnosis. Patients with high use of opioids also exhibit high work absence and productivity losses.

SIGNIFICANCE STATEMENT

This was the first study to estimate trajectories of opioids in the two time periods before and after a diagnosis of low back pain. For the first time, productivity losses were also estimated across the identified opioid use trajectories.

Effects of opioid drugs on immune function in cancer patients

Opioid receptor agonists are often used when cancer patients undergo surgery or analgesic treatment. As analgesics in clinical care, opioids can provide intraoperative or to chronic cancer pain relief. Immune function plays an important role in anti-cancer therapy, with cellular immunity, comprised principally of T-lymphocytes and natural killer cells, representing the primary anti-cancer immune response. However, it remains unclear whether immune function is further affected with the use of opioids in already immunocompromised cancer patients. This article provides a review of the effects of commonly used clinical opioids, including morphine, oxycodone, fentanyl and tramadol, on immune function in cancer patients. It provides a summary of current evidence regarding the immunomodulatory effects of opioids in the cancer setting and mechanisms underlying these interactions.

Neuroimaging of opioid effects in humans across conditions of acute administration, chronic pain therapy, and opioid use disorder

Evidence of central nervous system (CNS) exogenous opioid effects in humans has been primarily gained through neuroimaging of three participant populations: individuals after acute opioid administration, those with opioid use disorder (OUD), and those with chronic pain receiving opioid therapy. In both the brain and spinal cord, opioids alter processes of pain, cognition, and reward. Opioid-related CNS effects may persist and accumulate with longer opioid use duration. Meanwhile, opioid-induced benefits versus risks to brain health remain unclear. This review article highlights recent accumulating evidence for how exogenous opioids impact the CNS in humans. While investigation of CNS opioid effects has remained largely disparate across contexts of opioid acute administration, OUD, and chronic pain opioid therapy, integration across these contexts may enable advancement toward effective interventions.

Safe Management of Adverse Effects Associated with Prescription Opioids in the Palliative Care Population: A Narrative Review

In the palliative care population, prescription opioids are often considered viable pain relief options. However, in this complex patient population, the adverse effects of opioid medications should be identified and managed without delay. Common adverse effects can include constipation, nausea, somnolence, dizziness, vomiting, and pruritus. Less common adverse effects can include potentially lethal respiratory depression and cardiovascular effects. Critical aspects of safe opioid prescribing are recognition of side effects and knowledge of effective management strategies; prompt management is necessary for uninterrupted pain relief. Most complications are managed with general approaches such as dose reduction, opioid rotation, alternate routes of administration, and symptomatic management. The only opioid-induced complication for which US Food and Drug Administration-approved treatments currently exist is constipation. Treating laxative-refractory opioid-induced constipation (OIC) with peripherally acting mu-opioid receptor antagonists (PAMORAs), which block gastrointestinal opioid receptors, can restore gastrointestinal motility and fluid secretion. This narrative review discusses key complications of prescription opioid treatment and their management in the palliative care setting.

Receipt of prescription opioid medication is associated with increased mortality in an Israeli population

BACKGROUND

Despite Israel's increased use of prescription opioids, reported deaths resulting or associated with opioids have decreased, in fact dramatically, since 2005. This contrast is unique and difficult to explain. We sought to examine whether higher prescribed opioid dosages among adults without oncologic diagnoses were associated with higher all-cause mortality rates.

METHODS

A historical cohort study in Clalit Health Services, using a data repository including all adult patients prescribed opiates between 2010 and 2020, excluding patients with oncologic diagnoses. Patients were classified into three groups according to opioid use: below 50 Morphine milligram equivalents (MME) per day, 50 to 90 MME per day, and above 90 MME per day. Sex, Charlson comorbidity score, age and socioeconomic status were recorded. Mortality rates were compared between the dosage groups and compared to age-standardized mortality rates in the general population.

RESULTS

On multivariate analysis, patients receiving 90 or more MME per day were 2.37 (95%CI 2.1 to 2.68) more likely to have died compared to patients receiving below 50 MME per day. The respective hazard ratio among patients receiving between 50 and 90 MME per day was 2.23 (2.01 to 2.46). Among patients aged 18 to 50, standardized mortality ratios (SMRs) compared to the general population ranged between 5.4 to 8.6 among women, receiving between 50 and 90 MME per day, and between 8.07 and 10.7 among women receiving 90 or more MME per day. The respective SMRs among men were 1.2 to 3.8 and 2.7 to 5.4.

CONCLUSION

Increased opioid use is independently associated with increased all-cause mortality among non-oncological patients. This result is most notable among young adults with little or no known comorbidities. These findings are consistent with results in other countries and seem more credible than previous Israeli reports. Healthcare regulators and providers should, therefore, act to curtail the increasing opioid prescriptions and devise and enhance controls in the healthcare system, which, until 2020, had very limited mechanisms in place.

Persistence of analgesic usage and opioid consumption in sarcopenic patients undergoing neuraxial anesthesia: a nationwide retrospective cohort study

Introduction

This study investigates the association between chronic postsurgical pain (CPSP) and long-term postsurgical analgesic usage in patients undergoing neuraxial anesthesia, with a specific focus on the presence or absence of sarcopenia.

Objectives

To assess the rate of analgesic prescription, including opioids, at 3 and 6 months postsurgery for patients with and without preoperative sarcopenia, and to determine the impact of sarcopenia on analgesic use after neuraxial anesthesia surgery.

Methods

Patients undergoing surgery under neuraxial anesthesia were categorized into sarcopenic and nonsarcopenic groups based on preoperative diagnosis using the ICD-10-CM code M62.84. Propensity score matching in a 1:4 ratio was applied for group matching. Analgesic prescription rates were evaluated at 3 and 6 months postsurgery, and multivariable logistic regression was used to analyze analgesic use, comparing patients with and without preoperative sarcopenia.

Results

Among 3805 surgical patients, 761 had sarcopenia, while 3044 did not. At 3 months postsurgery, 62.3% of sarcopenic patients received analgesics, with 2.9% receiving opioids, compared to 57.1% of nonsarcopenic patients receiving analgesics and 0.8% receiving opioids. At 6 months postsurgery, 30.8% of sarcopenic patients received analgesics (1.7% opioids), while 26.3% of non-sarcopenic patients received analgesics (0.3% opioids). Multivariable logistic regression analysis revealed that preoperative sarcopenia was significantly associated with higher analgesic prescription rates at both 3 months (adjusted odds ratio [aOR], 1.27; 95% confidence interval [CI], 1.05-1.53) and 6 months (aOR, 1.17; 95% CI, 1.07-1.42) postsurgery. Furthermore, sarcopenic patients exhibited significantly higher opioid prescription rates at 3 months (aOR, 1.11; 95% CI, 1.05-2.45) and 6 months (aOR, 1.89; 95% CI, 1.12-4.96) postsurgery.

Conclusion

Sarcopenia emerges as an independent risk factor for prolonged analgesic use after neuraxial anesthesia surgery and significantly elevates the risk of developing CPSP.

Problems with opioids - beyond misuse

The U.S. is grappling with an opioid epidemic, with millions of adults on long-term opioid therapy (LTOT). Although patients often report pain relief and improved daily function with opioids, research shows no significant differences in short-term outcomes between opioid and non-opioid users, as well as no long-term opioid benefits. This scoping review aims to identify lesser-known side effects of long-term opioid use and increase awareness of them, allowing healthcare providers and patients to better assess the risks and benefits of opioid use. Our data search from PubMed and Google Scholar used keywords related to opioids, chronic pain, hypogonadism, endocrinopathies, cancer progression, cardiovascular events, renovascular events, sleep disturbances, mood disorders and others, narrowing down to English-language full articles published from January 2018 to April 2023. This review emphasizes the probable serious adverse consequences of long-term opioid use on various body systems in patients with chronic pain. Given the lack of long-term benefits and significant adverse effects, our review underscores the critical need for healthcare providers to include these risks in discussions with patients when considering the long-term use of opioid therapy.

Causal effects and immune cell mediators between prescription analgesic use and risk of infectious diseases: a Mendelian randomization study

Introduction

Clinical observations have found that prolonged use of analgesics increases the incidence of infection. However, the direct causal relationship between prescription analgesic use (PAU) and risk of infection (ROI) remains unclear.

Methods

This study used Mendelian randomization (MR) design to estimate the causal effect of PAU on ROI, as well as their mediating factors. Genetic data on prescription analgesics use and immune cells were obtained from published GWAS. Additionally, data on ROI were extracted from the FinnGen database. Two-sample MR analysis and multivariate MR (MVMR) analysis were performed using inverse variance weighting (IVW) to ascertain the causal association between PAU and ROI. Finally, 731 immune cell phenotypes were analyzed for their mediating role between analgesics and infection.

Results

Using two-sample MR, IVW modeling showed that genetically predicted opioid use was associated with increased risk of pulmonary infection (PI) (OR = 1.13, 95% CI: 1.05-1.21, p< 0.001) and upper respiratory infection (URI) (OR = 1.18, 95% CI: 1.08-1.30, p< 0.001); non-steroidal anti-inflammatory drugs (NSAIDs) were related to increased risk of skin and subcutaneous tissue infection (OR = 1.21, 95% CI: 1.05-1.39, p = 0.007), and antimigraine preparations were linked to a reduced risk of virus hepatitis (OR = 0.79, 95% CI: 0.69-0.91, p< 0.001). In MVMR, the association of opioids with URI and PI remained after accounting for cancer conditions. Even with a stricter threshold (p< 0.05/30), we found a significant causal association between opioids and respiratory infections (URI/PI). Finally, mediation analyses found that analgesics influence the ROI through different phenotypes of immune cells as mediators.

Conclusion

This MR study provides new genetic evidence for the causal relationship between PAU and ROI, and the mediating role of immune cells was demonstrated.

Substance abuse and male sexual dysfunction: what lies beneath?

INTRODUCTION

Substance abuse has become a worldwide health problem, leading to numerous consequences such as social problems among family members, abnormal behavior, adverse health effects, and psychological problems as well as economic consequences.

OBJECTIVES

We sought to assess the relationship between substance abuse and male sexual health.

METHODS

A search was carried out in the following databases: PubMed, MeSH (Medical Subject Headings), Science Direct, Scopus, Cochrane Library, EMBASE, CINAHL, Academic Search Complete, and the Egyptian Knowledge Bank. The following keywords were used to assess the outcomes for relevant associations: illicit drugs, addiction, substance abuse, sexual health, erectile dysfunction, ejaculatory disorders, impotence, orgasm disorders, and sexual performance.

RESULTS

The initial literature search identified a total of 148 articles in all searched databases. After removal of duplicate studies and application of inclusion/exclusion criteria, 75 reported studies were retained for review, including 38 case-control studies and 37 cross-sectional studies. These articles were classified into the following categories according to the type of abused substance addressed: cannabis/marihuana, 16 articles; opioids, 13 articles; heroin, 11 articles; cocaine, 5 articles; tramadol, 6 articles; ketamine, 2 articles; ecstasy, 4 articles; amphetamine, 2 articles; khat, 7 articles; androgen anabolic steroids, 2 articles; and polydrugs, 7 articles. Most of these recruited articles demonstrated a negative impact of the addressed substance on male sexual health, with variable levels.

CONCLUSION

Substance abuse has negative impacts on male sexual health that should be addressed. More studies conducted with proper methodological and statistical approaches, including logistic regression analysis, are needed to predict the effects of specific substances, considering the rapidly growing effects of non-substance-use disorders on male sexual health.

Pharmacological Methods of Pain Management: Narrative Review of Medication Used

Background

Pain management is a critical aspect of healthcare, aimed at alleviating discomfort and improving the quality of life for individuals experiencing acute or chronic pain. Pharmacological methods constitute a primary approach to pain management, including a diverse array of drugs that work through different mechanisms.

Aim

Identifying medications commonly employed in pain management, focusing on their mechanism of actions, uses, efficacy and pharmacological applications.

Methods

The methodology involved a systematic search of scientific literature using various databases, including PubMed, Scopus, and Google Scholar. Relevant articles published between 2000 and 2023 were screened for inclusion. The selected studies encompassed original research, review articles, therapeutic guidelines and randomized controlled trials.

Results

The findings of this review suggest that a multimodal approach combining various analgesics can enhance pain relief while minimizing adverse effects. It emphasizes the importance of assessing pain intensity, determining the underlying etiology, and utilizing evidence-based guidelines to optimize pain management outcomes.

Conclusion

Pharmacological methods of pain management are an essential component of pain management strategies to achieve optimal pain relief while minimizing adverse effects. The article concludes with a discussion on emerging trends and future directions in pharmacological pain management, including novel drug targets and advances in drug delivery systems.

Effects of Opioids on Immune and Endocrine Function in Patients with Cancer Pain

OPINION STATEMENT

Opioids are an important treatment in managing cancer pain. Uncontrolled pain can be detrimental to function and quality of life. Common adverse effects of opioids such as sedation, constipation and nausea are well recognised, but opioid effects on the endocrine and immune systems are less apparent. The evidence for the immunomodulatory effects of opioids suggest that some opioids might be immunosuppressive and that their use might be associated with reduced survival and increased rates of infection in patients with cancer. However, the quality of this evidence is limited. Opioid-induced endocrinopathies, in particular opioid-induced hypogonadism, may also impact cancer survival and impair quality of life. But again, evidence in patients with cancer is limited, especially with regard to their management. There are some data that different opioids influence immune and endocrine function with varying outcomes. For example, some opioids, such as tramadol and buprenorphine, demonstrate immune-sparing qualities when compared to others. However, most of this data is preclinical and without adequate clinical correlation; thus, no opioid can currently be recommended over another in this context. Higher opioid doses might have more effect on immune and endocrine function. Ultimately, it is prudent to use the lowest effective dose to control the cancer pain. Clinical presentations of opioid-induced endocrinopathies should be considered in patients with cancer and assessed for, particularly in long-term opioid users. Hormone replacement therapies may be considered where appropriate with support from endocrinology specialists.

Synthesis and biological evaluation of N-(benzene sulfonyl)acetamide derivatives as anti-inflammatory and analgesic agents with COX-2/5-LOX/TRPV1 multifunctional inhibitory activity

In this study, a series of structurally novel N-(benzene sulfonyl) acetamide derivatives were designed, synthesized, and biologically evaluated as COX-2/5-LOX/TRPV1 multitarget inhibitors for anti-inflammatory and analgesic therapy. Among them, 9a and 9b displayed favorable COX-2 (9a IC₅₀ = 0.011 μM, 9b IC₅₀ = 0.023 μM), 5-LOX (9a IC₅₀ = 0.046 μM, 9b IC₅₀ = 0.31 μM) and TRPV1 (9a IC₅₀ = 0.008 μM, 9b IC₅₀ = 0.14 μM) inhibitory activities. The pharmacokinetic (PK) study of 9a in SD rats at the dosage of 10 mg/kg demonstrated a high oral exposure, an acceptable clearance and a favorable bioavailability (Cmax = 5807.18 ± 2657.83 ng/mL, CL = 3.24 ± 1.47 mL/min/kg, F = 96.8 %). Further in vivo efficacy studies illustrated that 9a was capable of ameliorating formalin-induced pain and inhibiting capsaicin-induced ear edema.

Randomised, pragmatic, waitlist controlled trial of cannabis added to prescription opioid support on opioid dose reduction and pain in adults with chronic non-cancer pain: study protocol

INTRODUCTION

Chronic, non-cancer pain impacts approximately 50 million adults in the USA (20%), approximately 25% of whom receive chronic prescription opioids for pain despite limited empirical efficacy data and strong dose-related risk for opioid use disorder and opioid overdose. Also despite lack of efficacy data, there are many reports of people using cannabis products to manage chronic pain and replace or reduce chronic opioids. Here we describe the protocol for a randomised trial of the effect of cannabis, when added to a behavioural pain management and prescription opioid taper support programme, on opioid utilisation, pain intensity and pain interference.

METHODS

This is a pragmatic, single-blind, randomised, wait-list controlled trial that aims to enrol 250 adults taking prescription opioids at stable doses of ≥25 morphine milligram equivalents per day for chronic non-cancer pain who express interest in using cannabis to reduce their pain, their opioid dose or both. All participants will be offered a weekly, 24-session Prescription Opioid Taper Support group behavioural pain management intervention. Participants will be randomly assigned in 1:1 ratio to use cannabis products, primarily from commercial cannabis dispensaries or to abstain from cannabis use for 6 months. Coprimary outcomes are change in prescription monitoring programme-verified opioid dose and change in Pain, Enjoyment, General Activity scale scores. Secondary outcomes include quality of life, depression, anxiety, self-reported opioid dose and opioid and cannabis use disorder symptoms. All other outcomes will be exploratory. We will record adverse events.

ETHICS AND DISSEMINATION

This study has ethical approval by the Massachusetts General Brigham Institutional Review Board (#2021P000871). Results will be published in peer-reviewed journals and presented at national conferences.

TRIAL REGISTRATION NUMBER

NCT04827992.

Management of chronic non-cancer pain: a framework

Aim: Since publication of the CDC 2016 Guideline, opioid-related mortality in the USA has doubled and a crisis has developed among the 15-20 million Americans with chronic, moderate-to-severe, noncancer pain. Our aim was to develop a comprehensive alternative approach to management of chronic pain. Methods: Analytic review of the clinical literature. Results: Published science provides a solid framework for the management of chronic non-cancer pain, detailed here, even as it leaves many knowledge gaps, which we fill with insights from clinical experience. Conclusion: There is a sufficient basis in science and in clinical experience to achieve adequate control of chronic pain in nearly all patients in a way that adequately balances benefits and potential harms.