Gender, genetics, and analgesia: understanding the differences in response to pain relief

Fentanyl induces analgesic effect through miR-381-3p/TRPM7 when combined with bupivacaine in subarachnoid injection

Fentanyl combined with bupivacaine in subarachnoid anesthesia exerts a strong synergistic analgesic effect, extending the duration of analgesia. However, the mechanism of enhanced analgesic effect of fentanyl remains elusive. The present study investigated the potential mechanism of the analgesic effect of fentanyl when combined with bupivacaine. The subarachnoid injection (SI) rat model was employed, and SI of fentanyl or/and bupivacaine was used to investigate their analgesic effect. Dorsal root ganglion (DRG)' RNA sequencing (RNA-Seq) and bioinformatics analysis were performed to evaluate the downstream mechanisms of MicroRNAs (miRNAs). Further validation tests included RT-PCR, Western blot, and immunofluorescence. A single SI of fentanyl or bupivacaine decreased the positive responses to stimulation when used alone or in combination. RNA-seq results revealed that miR-381-3p played a role in the fentanyl-driven promotion of analgesia. Bioinformatics analysis and dual-luciferase reporter identified TRPM7 as a direct downstream target gene of miR-381-3p. In vitro, overexpression of miR-381-3p could further block fentanyl-induced expression of TRPM7, p-ERK1/2, CGRP, and SP. In addition, antagomir-381-3p reversed the inhibitory effect of fentanyl on the expression of TRPM7, p-ERK1/2, CGRP, and SP, in vivo; however, TRPM7 siRNA rescued the effect of antagomir-381-3p. In conclusion, fentanyl inhibits p-ERK by targeting TRPM7 via miR-381-3p, lowering the production of CGRP and SP, and ultimately inducing analgesic effects.

Sex Differences in Chronic Postsurgical Pain after Open Thoracotomy

STUDY OBJECTIVE

To determine the incidence of chronic postsurgical pain (CPSP) in women after open thoracotomy. Secondary objectives were to compare relevant patient and procedural variables between women and men.

DESIGN

Observational cohort study.

SETTING

Ten university-affiliated hospitals.

SUBJECTS

Ninety-six women and 137 men.

INTERVENTIONS

Scheduled open thoracotomy.

MEASUREMENTS

Pain histories, psychological measures, and perceived health status and catastrophizing scores were obtained. The diagnosis of chronic postsurgical pain was by physical examination at 4 months. Standard preoperative, intraoperative, and postoperative data were also recorded.

MAIN RESULTS

The chronic postsurgical pain incidence was significantly higher in women (53.1%) than in men (38.0%) (p = 0.023). At baseline, women had significantly worse scores on psychological measures (perception of mental state [p = 0.01], depression [p = 0.006], and catastrophizing [p < 0.001]). Women also reported more preoperative pain in the operative area (p = 0.011) and other areas (p = 0.030).

CONCLUSION

These findings show that the incidence of physician-diagnosed chronic postsurgical pain is higher in women than in men after surgeries involving thoracotomy. Sex and gender should be included in future clinical research on pain in surgical settings.

Molecular Sex Differences and Clinical Gender Efficacy in Opioid Use Disorders: From Pain Management to Addiction

Opioids have been utilized for both medical and recreational purposes since their discovery. Primarily recognized for their analgesic properties, they are also associated with the development of tolerance and dependence, contributing to a significant public health concern worldwide. Sex differences in opioid use disorder reveal that while men historically exhibit higher rates of abuse, women may develop dependence more quickly and are more susceptible to the addictive nature of opioids. This narrative review explores sex differences in opioid response in both clinical and experimental models, focusing on opioid receptor mechanisms, pain modulation, and hormonal influences. Additionally, it discusses the complexities of opioid addiction and withdrawal, highlighting sex-specific responses and the role of opioid replacement therapies. Diverse experimental outcomes, together with observational data, underscore the need for further research into sex-specific opioid biological mechanisms in a wider context, including demographic, cultural, and health-related factors. A comprehensive understanding of these complexities holds the potential to enhance personalized opioid therapies.

Fibromyalgia in obstructive sleep apnea-hypopnea syndrome: a systematic review and meta-analysis

Introduction: Fibromyalgia (FM) is a common condition in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). This meta-analysis aimed to evaluate differences in sleep monitoring indicators between patients with OSAHS and positive FM and patients with OSAHS and negative FM and to determine the incidence of FM in patients with OSAHS. Methods: An exhaustive literature review was conducted to analyze the incidence of FM in patients with OSAHS, using online databases, including PubMed, EMBASE, Web of Science, CNKI, and Wanfang, both in English and Chinese. The quality of the included studies was assessed by two researchers using the Newcastle-Ottawa Scale scores. The acquired data were analyzed using Stata 11.0 software. Continuous variables were combined and analyzed using the weighted mean difference as the effect size. Conjoint analyses were performed using random-effects (I2 > 50%) or fixed-effect (I2 ≤ 50%) models based on I2 values. Results: Fourteen studies met the inclusion criteria. This study showed that 21% of patients with OSAHS experienced FM. Subgroup analyses were performed based on race, age, sex, body mass index, and diagnostic criteria for patients with OSAHS. These findings indicate that obese patients with OSAHS have a higher risk of FM, similar to females with OSAHS. Regarding most sleep monitoring indicators, there were no discernible differences between patients with OSAHS with positive FM and those with negative FM. However, patients with positive FM had marginally lower minimum arterial oxygen saturation levels than those with negative FM. The current literature suggests that patients with OSAHS have a high incidence of FM (21%), and FM has little effect on polysomnographic indicators of OSAHS. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024510786, identifier CRD42024510786.

The Effects of Sex Hormones on Postoperative Pain in Patients with Laparoscopic Cholecystectomy

OBJECTIVE

There are many factors that affect postoperative pain. This study determines the effect of preoperative sex hormone levels on postoperative pain levels in patients undergoing laparoscopic cholecystectomy.

PATIENTS AND METHODS

This study included a total of 89 patients who met the study inclusion criteria. The patients were divided into 3 groups based on their sex and pre and postmenopausal periods: male patients (n = 28), postmenopausal female patients (n = 31), and female patients with normal cycles (n = 30). Normal-cycle women were also regrouped based on their follicular and luteal phases. Data were collected using a descriptive characteristics form, a patient follow-up form, and the Visual Analog Scale.

RESULTS

Venous blood samples taken from the patients before surgery were used to measure their levels of estradiol (EST), testosterone (TES), and progesterone levels. Male patients had lower pain levels than female patients. The male patients' Visual Analog Scale scores were inversely related and correlated strongly with their TES levels ( P < 0.05). However, subgroup analyses suggested that their EST level played a primary role in males and that the EST/TES ratio was determinant in the late postoperative period. In female patients, the EST/progesterone ratio was the most determining factor for the level of pain felt in the postmenopausal period, whereas there was no change in the premenopausal period at different stages of the menstrual cycle.

CONCLUSIONS

Sex hormones were found to be effective in predicting postoperative pain severity.

Tumor necrosis factor receptor 2 activation elicits sex-specific effects on cortical myelin proteins and functional recovery in a model of multiple sclerosis

Multiple sclerosis (MS), a demyelinating autoimmune disease of the central nervous system (CNS), predominately affects females compared to males. Tumor necrosis factor (TNF), a pro-inflammatory cytokine, signaling through TNF receptor 1 contributes to inflammatory disease pathogenesis. In contrast, TNF receptor 2 signaling is neuroprotective. Current anti-TNF MS therapies are shown to be detrimental to patients due to pleiotropic effects on both pro- and anti-inflammatory functions. Using a non-pertussis toxin (nPTX) experimental autoimmune encephalomyelitis (EAE) model in C57BL/6 mice, we systemically administered a TNFR2 agonist (p53-sc-mTNFR2) to investigate behavioral and pathophysiological changes in both female and male mice. Our data shows that TNFR2 activation alleviates motor and sensory symptoms in females. However, in males, the agonist only alleviates sensory symptoms and not motor. nPTX EAE induction in TNFR2 global knockout mice caused exacerbated motor symptoms in females along with an earlier day of onset, but not in males. Our data demonstrates that TNFR2 agonist efficacy is sex-specific for alleviation of motor symptoms, however, it effectively reduces mechanical hypersensitivity in both females and males. Altogether, these data support the therapeutic promise TNFR2 agonism holds as an MS therapeutic and, more broadly, to treat central neuropathic pain.

Why do we keep ignoring sex in kidney disease?

Throughout the history of nephrology, little attention has been paid to the sex and gender differences in kidney disease. This lack of awareness prevents optimal diagnosis and management of kidney disease. In today's world of precision medicine, it is imperative to appreciate the differential factors regarding gender and kidney disease. This editorial summarizes the up-to-date literature regarding sex and gender differences in kidney disease and considers areas where knowledge is incomplete and where further research is needed. We address sex-specific effects on chronic kidney disease epidemiology; risks of dialysis underdosing and medication overdosing in women; unexplained loss of female sex advantage in life expectancy during dialysis, and impact of sex on diagnosis and management of genetic kidney disease. We also aim to highlight the impact of gender on kidney health and raise awareness of disparities that may be faced by women, and transgender and gender-diverse persons when a male-model approach is used by healthcare systems. By understanding the link between sex and kidney disease, kidney specialists can improve the care and outcomes of their patients. In addition, research on this topic can inform the development of targeted prevention and intervention strategies that address the specific needs and risk factors of different populations.

Adverse Drug Reactions to Opioids: A Study in a National Pharmacovigilance Database

INTRODUCTION

Opioids are commonly used as analgesics; however, like any medicine, they can produce adverse drug reactions (ADRs), including nausea, constipation, dependence, and respiratory depression, that result in harmful and fatal events. Therefore, it is essential to monitor the safety of these drugs in clinical practice.

OBJECTIVE

This study aimed to characterize the safety profile of opioids by conducting a descriptive study based on a spontaneous reporting system (SRS) for ADRs in The Netherlands, focusing on abuse, misuse, medication errors, and differences between sexes.

METHODS

Reports submitted to the Netherlands Pharmacovigilance Centre Lareb from January 2003 to December 2021 with an opioid drug as the suspected/interacting medicine were analyzed. Reporting odds ratios (RORs) for drug-ADR combinations were calculated, analyzed, and corrected for sex and drug utilization (expenditure) for the Dutch population.

RESULTS

A total of 8769 reports were analyzed. Tramadol was the opioid with the most reports during the period (n = 2746), while oxycodone or tramadol had the highest number of reports per year in the study period. The most reported ADRs from opioid use were nausea, followed by dizziness and vomiting, independent of sex, and all of them were more often reported in women. Vomiting associated with tramadol (ROR females/males = 2.17) was significantly higher in women. Buprenorphine was responsible for most ADRs when corrected for expenditure, with high RORs observed with application site hypersensitivity, application site reaction, and application site rash. Fentanyl gave rise to most of the reports of ADRs concerning abuse, misuse, and medication errors.

CONCLUSION

Patients treated with opioids experienced ADRs, primarily nausea, dizziness, and vomiting. For those groups of drugs, no significant differences were found between the sexes, except for the vomiting associated with tramadol. In general, ADRs related to opioids presented higher RORs when uncorrected and corrected for sexes and expenditure than other drugs. There was more disproportionate reporting for ADRs concerning abuse, misuse, and medication errors for opioids than other drugs in the Dutch SRS.

Navigating cultural competence in district nursing

Cultural diversity is an evolving feature of modern-day society. It is recognised that many factors contribute to culturally competent care and evidence suggests there are still inequalities in care provision to some populations. District nurses (DN) deliver care to individuals', families and communities across varying demographics, and aim to provide high quality evidencebased, person-centred care. The scope of the DN and the community nursing team's practice is far reaching and extends across generations and an array of chronic complex health conditions. Therefore, it is imperative that DNs are aware of aspects surrounding cultural diversity, to ensure they can holistically assess and manage patients on their caseloads and support teams to practice culturally competent care. This article aims to provide an outline of key areas for exploration in cultural competence. It will highlight communication, pain, end of life, nutrition and health disparities to consider barriers and challenges for district nursing practice.

Early pain in females is linked to late pathological features in murine experimental osteoarthritis

Background

Osteoarthritis (OA) is a progressive joint disease and a major cause of chronic pain in adults. The prevalence of OA is higher in female patients, who tend to have worse OA outcomes, partially due to pain. The association between joint pain and OA pathology is often inconclusive. Preclinical research studies have largely overlooked sex as a potential determinant in joint pain during OA. This study aimed to investigate the role of sex in joint pain in the collagenase-induced OA (CiOA) model and its link with joint pathology.

Methods

Multiple aspects of pain were evaluated during identically executed experiments of CiOA in male and female C57BL/6J mice. Cartilage damage, osteophyte formation, synovial thickness, and cellularity were assessed by histology on day 56. The association between pain and pathology was investigated, disaggregated by sex.

Results

Differences in pain behavior between sexes were found in the majority of the evaluated pain methods. Females displayed lower weight bearing ability in the affected leg compared to males during the early phase of the disease, however, the pathology at the end stage was comparable between sexes. In the second cohort, males displayed increased mechanical sensitivity in the affected joint compared to females but also showed more cartilage damage at the end stage of the model. Within this cohort, gait analysis showed varied results. Males used the affected paw less often and displayed dynamic weight-bearing compensation in the early phase of the model. These differences were not observed in females. Other evaluated parameters displayed comparable gait behavior between males and females. A detailed analysis of individual mice revealed that seven out of 10 pain measurements highly correlated with OA histopathology in females (Pearson r range: 0.642-0.934), whereas in males this measurement was only two (Pearson r range: 0.645-0.748).

Conclusion

Our data show that sex is a determinant in the link between pain-related behavior with OA features. Therefore, to accurately interpret pain data it is crucial to segregate data analysis by sex to draw the correct mechanistic conclusion.

Gender Differences in Visual Functioning Questionnaire Scores among Patients with Age-Related Macular Degeneration

PURPOSE

To examine gender differences in visual functioning using the National Eye Institute Visual Functioning Questionnaire-25 (VFQ-25) in a Colorado cohort of patients with age-related macular degeneration (AMD).

METHODS

A retrospective cohort study was conducted using a registry of AMD patients who attended the Sue Anschutz-Rodgers Eye Center (2014 to 2019). Demographic, clinical, and image data were collected, and AMD was categorized as Early/Intermediate AMD, or unilateral/bilateral neovascular (NV) AMD, geographic atrophy (GA), or Both Advanced using the Beckman Classification. Each patient completed the VFQ-25, which evaluates visual functioning, generating a composite score and subscale scores for vision-specific activities. Univariate and multivariable general linear models were used to estimate the associations between gender and VFQ-25 scores with parameter estimates (PE) and standard errors (SE).

RESULTS

Among 739 patients with AMD, 294 (39.8%), 115 (15.6%), 168 (22.7%), and 162 (21.9%) were diagnosed with Early/Intermediate AMD, GA, NV AMD, and Both Advanced, respectively. Adjusted for AMD classification, age and habitual visual acuity in the better-seeing and worse-seeing eyes, female gender was not significantly associated with lower composite VFQ-25 scores (PE (SE): -1.2 (0.9), p = .193), and was significantly associated with reportedly worse ocular pain and driving subscale scores (PE (SE): -4.6 (1.0), p < .0001 and -9.1 (2.1), p < .0001, respectively).

CONCLUSION

Gender plays a role in reported driving activities and ocular pain among patients with AMD. This may need to be accounted for in future research related to the use of VFQ-25 for AMD.

Sex-Related Differences in Pharmacological Response to CNS Drugs: A Narrative Review

In the last decades, both animal and human studies have neglected female subjects with the aim of evading a theorized intricacy of feminine hormonal status. However, clinical experience proves that pharmacological response may vary between the two sexes since pathophysiological dissimilarities between men and women significantly influence the pharmacokinetics and pharmacodynamics of drugs. Sex-related differences in central nervous system (CNS) medication are particularly challenging to assess due to the complexity of disease manifestation, drugs’ intricate mechanisms of action, and lack of trustworthy means of evaluating the clinical response to medication. Although many studies showed contrary results, it appears to be a general tendency towards a certain sex-related difference in each pharmacological class. Broadly, opioids seem to produce better analgesia in women especially when they are administered for a prolonged period of time. On the other hand, respiratory and gastrointestinal adverse drug reactions (ADRs) following morphine therapy are more prevalent among female patients. Regarding antidepressants, studies suggest that males might respond better to tricyclic antidepressants (TCAs), whereas females prefer selective serotonin reuptake inhibitors (SSRI), probably due to their tolerance to particular ADRs. In general, studies missed spotting any significant sex-related differences in the therapeutic effect of antiepileptic drugs (AED), but ADRs have sex variations in conjunction with sex hormones’ metabolism. On the subject of antipsychotic therapy, women appear to have a superior response to this pharmacological class, although there are also studies claiming the opposite. However, it seems that reported sex-related differences regarding ADRs are steadier: women are more at risk of developing various side effects, such as metabolic dysfunctions, cardiovascular disorders, and hyperprolactinemia. Taking all of the above into account, it seems that response to CNS drugs might be occasionally influenced by sex as a biological variable. Nonetheless, although for each pharmacological class, studies generally converge to a certain pattern, opposite outcomes are standing in the way of a clear consensus. Hence, the fact that so many studies are yielding conflicting results emphasizes once again the need to address sex-related differences in pharmacological response to drugs.

Innate Immunity at the Core of Sex Differences in Osteoarthritic Pain?

Osteoarthritis (OA) is a progressive whole-joint disease; no disease-modifying drugs are currently available to stop or slow its process. Symptoms alleviation is the only treatment option. OA is the major cause of chronic pain in adults, with pain being the main symptom driving patients to seek medical help. OA pathophysiology is closely associated with the innate immune system, which is also closely linked to pain mediators leading to joint pain. Pain research has shown sex differences in the biology of pain, including sexually dimorphic responses from key cell types in the innate immune system. Not only is OA more prevalent in women than in men, but women patients also show worse OA outcomes, partially due to experiencing more pain symptoms despite having similar levels of structural damage. The cause of sex differences in OA and OA pain is poorly understood. This review provides an overview of the involvement of innate immunity in OA pain in joints and in the dorsal root ganglion. We summarize the emerging evidence of sex differences regarding innate immunity in OA pain. Our main goal with this review was to provide a scientific foundation for future research leading to alternative pain relief therapies targeting innate immunity that consider sex differences. This will ultimately lead to a more effective treatment of pain in both women and men.

Effect of topical local anaesthesia on injection pain associated with administration of sterile water injections - a randomized controlled trial

Background

Sterile water injections can provide effective pain relief during childbirth, particularly for low back pain related to childbirth. However, the pain associated administering the injections can negatively impact women’s impressions of the procedure. It may discourage women from considering repeat doses despite the quality of analgesia experienced. Determining strategies to reduce the pain related to the administration of sterile water injections would improve the acceptability of the technique. Therefore, the aim of this study was to evaluate the effect of topical local anesthesia on the pain associated with administration of sterile water injections.

Methods

The study was designed as a multi-arm single-blind, randomized, controlled trial and 120 female healthy students were randomly divided according to one of four groups. The Intervention group received sterile water injections with topical local anesthesia. Control group 1 received sterile water injections without topical local anesthesia, control group 2 received injections of isotonic saline 0.9% with topical local anesthesia and control group 3 received injections of isotonic saline 0.9% without topical local anesthesia. Pain Immediately after the injections and subsidence in pain were recorded using a visual analogue scale. Sensations in the injection area were reported 15 min and the day after the injections.

Results

The main finding of this study was that local anesthesia with EMLA® reduces the pain associated with the administration of intracutaneous sterile water injections. There was a significant difference in the self-assessed pain score immediately following the injections between the control (73.3 mm) and intervention groups (50.0 mm), p = 0.001. No adverse side effects were reported.

Conclusion

Local anesthesia with EMLA® reduces the pain associated with intracutaneous administration of sterile water injections.

Trial registration

The study was registered 08/07/2014 at ClinicalTrials.gov Identifier: NCT02213185.

Familial episodic pain syndrome: a case report and literature review

The purpose of this case report and literature review is to show that familial episodic pain syndrome (FEPS) is a non-inflammatory genetically inherited pain syndrome. A 3-year-old boy presented at our hospital with pain in both his forearms and lower limbs below the knees for more than 3 years. There were no abnormalities in the blood tests, blood smears, liver and kidney function tests, trace elements tests, cellular immunity test, humoral immunity test, autoantibody tests, C-reactive protein (CRP) test, erythrocyte sedimentation rate (ESR) test, and tumor-related and bone marrow cytology examinations. Additionally, the imaging examination results showed no abnormalities. From the patient's medical history, we found that the mother of the child had a family history of a similar disease. To date, only 21 cases of FEPS3 caused by the sodium voltage-gated channel alpha subunit 11A (SCN11A) gene mutation have been reported. Although the age of onset is different, most of them are inherited in families. The results of the genetic examination revealed that the pain mainly came from the genetic inheritance of the maternal family line. The whole exon gene test revealed that the pain was caused by 2 heterozygous mutations of c.674G > T and c.671T > C in the SCN11A gene.

Tapentadol and Oxycodone/Naloxone Prescribing Patterns in Primary Health Care in Catalonia, Spain: A Cross-Sectional Study

Objective

To characterize the use of tapentadol and the combination oxycodone/naloxone in primary health care. Data on their use and possible misuse will allow the identification of risk factors and to design protocols to reduce and prevent avoidable harm to patients being treated for pain.

Design

A descriptive, cross-sectional and multicenter study was performed.

Setting

Fifty-three primary health care teams, which provides healthcare for 1,300,000 inhabitants.

Patients

A total of 1840 patients had active prescriptions of tapentadol and 985 of oxycodone/naloxone.

Methods

Demographic (age, sex) and clinical (glomerular filtration rate; active liver disease; dosing and duration of treatment), prescribed daily dose (according to age, sex, length of treatment), concomitant analgesic treatment and diagnosis. Patient information was obtained from medical records.

Results

Most of the patients were women (>74.0% in both cases), and the average age was 69.3 years (women: 70.1±13.2; men: 66.7±13.9 years) in the case of tapentadol and 70.6 years (women: 64.0±13.6; men: 72.6±14.3 years) in the case of oxycodone/naloxone. Only 12.2% of patients taking tapentadol and 12.1% taking oxycodone/naloxone had a normal renal function. In both cases, 4.1% of patients had active liver disease. The average length of treatment was 246.4 days in oxycodone/naloxone and 199.0 days in tapentadol. It was recorded that 85.1% of patients in the case of tapentadol and 89.0% in the oxycodone/naloxone had at least another drug prescribed for pain. About 42.2% of patients treated with tapentadol and 34.4% of patients treated with oxycodone/naloxone had associated neuralgia as a diagnosis.

Conclusion

The pattern of use and profile of patients with tapentadol and oxycodone/naloxone had more similarities than differences, and suggested that prescribing practice, and monitoring should be assessed regularly to ensure patient safety and effective management of pain.

Gender Difference in Pain Management Among Adult Cancer Patients in Saudi Arabia: A Cross-Sectional Assessment

Objective

To compare gender differences in pain management among adult cancer patients in Saudi Arabia and to explore the predictors associated with attitudinal barriers of cancer patients to pain management.

Methods

A descriptive cross-sectional study was conducted among 325 cancer patients from tertiary hospitals in Saudi Arabia.

Result

Of the total participants, 67.4% were women (N = 219) and 32.6% were men (N = 106). The overall mean scores of the attitudinal barriers questionnaire were 49.51 ± 13.73 in men and 54.80 ± 22.53 in women. The analysis shows significant differences in scores in subscales of tolerance (men = 7.48 ± 2.37), (women = 8.41 ± 3.01) (p = 0.003) and fear of distraction in the course of treatment (men = 6.55 ± 1.34), and (women = 7.15 ± 2.63) (p = 0.008). Female patients reported a more moderate to severe level of pain than men (worst pain in last week of 7.07 ± 1.50, worst pain in last week of 5.84 ± 2.65, respectively). Splitting by gender, the significant predictor for physiology effect domains in male cancer patients includes age, marital status, employment status, monthly income, cancer type, and presence of comorbid disease (p < 0.050). Age was a significant predictor of the domains of fatalism, communication, and harmful effects (p < 0.050) among female cancer patients.

Conclusion

The present study revealed significant differences between men and women with attitudinal barriers to cancer pain management. Managing pain requires the involvement of all methods in a comprehensive manner, thus unalleviated pain influences the patient's psychological or cognitive aspect.

Tapentadol versus oxycodone analgesia and side effects after laparoscopic hysterectomy: A randomised controlled trial

BACKGROUND

Tapentadol is an opioid, which acts as a μ-opioid receptor agonist and inhibits noradrenaline reuptake in the central nervous system. This dual mechanism of action results in synergistic analgesic effects and potentially less side effects. This has been shown in treatment of chronic pain but postoperative studies are sparse.

OBJECTIVES

The main aim was to compare the analgesic effect of tapentadol with oxycodone after laparoscopic hysterectomy. Opioid side effects were recorded as secondary outcomes.

DESIGN

Randomised, blinded trial.

SETTING

Single-centre, Oslo University Hospital, Norway, December 2017 to February 2019.

PATIENTS

Eighty-six opioid-naïve American Society of Anesthesiologists physical status 1 to 3 women undergoing laparoscopic hysterectomy for nonmalignant conditions.

INTERVENTION

The patients received either oral tapentadol (group T) or oxycodone (group O) as part of multimodal pain treatment. Extended-release study medicine was administered 1 h preoperatively and after 12 h. Immediate-release study medicine was used as rescue analgesia.

MAIN OUTCOME MEASURES

Pain scores, opioid consumption and opioid-induced side effects were evaluated during the first 24 h after surgery.

RESULTS

The groups scored similarly for pain at rest using a numerical rating scale (NRS) 1 h postoperatively (group T 4.4, 95% CI, 3.8 to 5.0, group O 4.6, 95% CI, 3.8 to 5.3). No statistically significant differences were found between the groups for NRS at rest or while coughing during the 24-h follow-up period (P = 0.857 and P = 0.973). Mean dose of oral rescue medicine was similar for the groups (P = 0.914). Group T had significantly lower odds for nausea at 2 and 3 h postoperatively (P = 0.040, P = 0.020) and less need for antiemetics than group O. No differences were found for respiratory depression, vomiting, dizziness, pruritus, headache or sedation.

CONCLUSION

We found tapentadol to be similar in analgesic efficacy to oxycodone during the first 24 h after hysterectomy, but with significantly less nausea.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03314792.

Pediatric Urologic Surgery: Reducing Opioid Use

Adequate pain management is important for successful postoperative recovery after any surgical procedure. Unfortunately, the USA and many other parts of the world are in the midst of an opioid epidemic, and healthcare providers are thus tasked with balancing the comfort and recovery of their patients after an operation against the individual and societal harms of the over-prescription of opioids. The goal of this article is to discuss the range of opioid formulations currently in use, examine why this may be problematic, and explore alternatives that provide similar efficacy and may improve overall safety in the pediatric population after urologic surgery. Improving the way opioids are prescribed through clinical practice guidelines as well as considering alternatives to opioids can ensure patients have access to safer and more effective pain treatments and potentially reduce opioid misuse.

Influence of sex and gender on the management of late-stage knee osteoarthritis

PURPOSE

The exact nature of sex and gender differences in knee osteoarthritis (OA) among patient candidates for total knee arthroplasty (TKA) remains unclear and requires better elucidation to guide clinical practice. The purpose of this investigation was to survey physician practices and perceptions about the influence of sex and gender on knee OA presentation, care, and outcomes after TKA.

METHODS

The survey questions were elaborated by a multidisciplinary scientific board composed of 1 pain specialist, 4 orthopedic specialists, 2 physiatrists, and 1 expert in gender medicine. The survey included 5 demographic questions and 20 topic questions. Eligible physician respondents were those who treat patients during all phases of care (pain specialists, orthopedic specialists, and physiatrists). All survey responses were anonymized and handled via remote dispersed geographic participation.

RESULTS

Fifty-six physicians (71% male) accepted the invitation to complete the survey. In general, healthcare professionals expressed that women presented worse symptomology, higher pain intensity, and lower pain tolerance and necessitated a different pharmacological approach compared to men. Pain and orthopedic specialists were more likely to indicate sex and gender differences in knee OA than physiatrists. Physicians expressed that the absence of sex and gender-specific instruments and indications is an important limitation on available studies.

CONCLUSIONS

Healthcare professionals perceive multiple sex and gender-related differences in patients with knee OA, especially in the pre- and perioperative phases of TKA. Sex and gender bias sensitivity training for physicians can potentially improve the objectivity of care for knee OA among TKA candidates.

Pain control and related factors in hospitalized patients

Pain is a common health problem for hospitalized patients. It is necessary to understand the factors that affect patients' pain to provide individual and complete pain management. This study explored the severity and incidence of pain in hospitalized patients on the admission day, during the hospitalization, and the discharge day, and explored the predictive factors that affect the patient's pain on the discharge day.This was a retrospective study that reviewed the medical records of 73,814 hospitalized patients from January 2016 to April 2018. The number of pain assessments was 471,339.The incidence of pain on the discharge day of patients was significantly higher than that on the admission day. The factors that affect and predict the pain of patients on discharge day include the degree of pain on the day of admission, emotional distress on the day of discharge, disease category, gender, age, and length of stay in hospital. It shows that the higher the degree of pain on the day of admission, the higher the degree of emotional distress on the day of discharge, female patients, younger patients, longer hospitalization days, and surgical and gynecological patients have significantly higher pain levels on the day of discharge (P < .05).This study found that the incidence of pain on the discharge day of patients was 46.5%. Previous pain level, disease category, emotional distress, gender, age, and length of hospital stay were important factors affecting patient pain on the discharge day. The influencing factors of patient pain should be fully assessed to provide individual and complete pain management, and improve patient quality of life after discharge.

Neuroimmune Mechanisms as Novel Treatment Targets for Substance Use Disorders and Associated Comorbidities

Recent studies examining the neurobiology of substance abuse have revealed a significant role of neuroimmune signaling as a mechanism through which drugs of abuse induce aberrant changes in synaptic plasticity and contribute to substance abuse-related behaviors. Immune signaling within the brain and the periphery critically regulates homeostasis of the nervous system. Perturbations in immune signaling can induce neuroinflammation or immunosuppression, which dysregulate nervous system function including neural processes associated with substance use disorders (SUDs). In this review, we discuss the literature that demonstrates a role of neuroimmune signaling in regulating learning, memory, and synaptic plasticity, emphasizing specific cytokine signaling within the central nervous system. We then highlight recent preclinical studies, within the last 5 years when possible, that have identified immune mechanisms within the brain and the periphery associated with addiction-related behaviors. Findings thus far underscore the need for future investigations into the clinical potential of immunopharmacology as a novel approach toward treating SUDs. Considering the high prevalence rate of comorbidities among those with SUDs, we also discuss neuroimmune mechanisms of common comorbidities associated with SUDs and highlight potentially novel treatment targets for these comorbid conditions. We argue that immunopharmacology represents a novel frontier in the development of new pharmacotherapies that promote long-term abstinence from drug use and minimize the detrimental impact of SUD comorbidities on patient health and treatment outcomes.

Pain in Women: A Perspective Review on a Relevant Clinical Issue that Deserves Prioritization

Introduction

Gender equity and gender medicine are opportunities not to be missed, and this Expert Group Opinion Paper on pain in women aims to review the treatment of pain conditions mainly affecting women, as well as the fundamental aspects of the different clinical response to drug treatment between the genders, and what can be done for gender-specific rehabilitation.

Methods

Perspective review.

Results

Genotypic and phenotypic differences in pain between the sexes are conditioned by anatomical, physiological, neural, hormonal, psychological, social, and cultural factors, such as the response to pharmacological treatment to control pain. The examination of these factors shows that women are affected by pain diseases more frequently and severely than men and that they report pain more frequently and with a lower pain threshold than men. Some forms of pain are inherently related to gender differences, such as pain related to the genitourinary system. However, other forms of chronic pain are seen more frequently in women than men, such as migraine, rheumatological, and musculoskeletal pain, in particular fibromyalgia.

Discussion

Research is needed into the pathophysiological basis for gender differences in the generation of acute pain and maintenance of chronic pain, including the factors that put women at higher risk for developing chronic pain. In addition, different specialties need to collaborate to develop gender-related diagnostic and therapeutic guidelines, and healthcare professionals need to upskill themselves in the appropriate management of pain using existing diagnostic tools and therapeutic options.

Non-Steroidal Anti-Inflammatory Drugs: Pharmacokinetics and Mitigation of Procedural-Pain in Cattle

Common routine management practices in cattle, such as castration and disbudding, are recognized as being painful. In the United States (U.S.), these procedures are frequently performed without pain mitigation and there are currently no drugs federally approved for such use. Non-steroidal anti-inflammatory drugs, such as meloxicam, flunixin meglumine and aspirin, are the most commonly used analgesics in U.S. food-animal production systems. However, the body of research investigating the effectiveness of these pharmaceuticals to control pain in cattle at castration and disbudding has not been comprehensively evaluated. Therefore, this review examined existing literature to summarize meloxicam, flunixin and aspirin (1) pharmacokinetics (PK) and (2) administration outcome in regard to pain control during castration and disbudding procedures, in cattle. Following systematic searches and screening, 47 PK and 44 publications were extracted for data and are presented. The sample size contained notable variability and a general deficiency of validated and replicated methodologies for assessing pain in cattle remain substantial challenges within this research area. Future research should prioritize replication of pain assessment methodologies across different experimental conditions to close knowledge gaps identified by the present study and facilitate examination of analgesic efficacy.

The pharmacogenetics of opioid treatment for pain management

BACKGROUND

Opioids are widely used as an analgesic for the treatment of moderate to severe pain. However, there are interindividual variabilities in opioid response. Current evidence suggests that these variabilities can be attributed to single nucleotide polymorphisms in genes involved in opioid pharmacodynamics and pharmacokinetics. Knowledge of these genetic factors through pharamacogenetic (PGx) testing can help clinicians to more consistently prescribe opioids that can provide patients with maximal clinical benefit and minimal risk of adverse effects.

AIM

The research outlined in this literature review identifies variants involved in opioid PGx, which may be an important tool to achieving the goal of personalized pain management.

RESULTS

Cytochrome P450 (CYP) 2D6, CYP3A4, CYP3A5, catechol-o-methyltransferase (COMT), adenosine triphosphate binding cassette transporter B1 (ABCB1), opioid receptor mu 1 (OPRM1), and opioid receptor delta 1 (OPRD1) are all important genes involved in opioid drug response, side effect profile and risk of dependence; these are important genetic factors that should be included in potential opioid PGx tests for pain management.

CONCLUSIONS

Employing a PGx-guided strategy for prescribing opioids can improve response rate, reduce side effects and increase adherence to treatment plans for pain; more research is needed to explore opioid-related PGx factors for the development and validation of an opioid genetic panel. Optimal prescriptions could also provide healthcare payers with beneficial savings, while reducing the risk of propagating the current opioid crisis.

Medication use among older people in Europe: Implications for regulatory assessment and co-prescription of new medicines

AIMS

The aim of this study was to elucidate drug prescription patterns in older European people with the objective to support regulatory contextualisation of (1) the suitability of enrolment criteria for new clinical trials; and (2) the understanding of the potential interactions/incompatibilities of newly authorised medicines with those most frequently used by older people.

METHODS

Medicines agencies in Portugal, Poland, Slovakia and England were approached to provide a list of the 10 most frequent prescriptions in 2016 for systemically used medicines per active substances (i.e. ATC level 5), in older people. For each active substance and for the most common therapeutic subgroups (i.e. ATC level 2), the percentages of older patients receiving at least one prescription were calculated per older age categories (65-74; 75-84; 85+) and gender.

RESULTS

There was considerable alignment in the most commonly prescribed active substances and therapeutic subgroups represented; these were gastroprotectants (A02), lipid-modifying agents (C10) and analgesics (N02). Some gender differences were observed (A02 and N02 were prescribed more frequently to women), but trends on age categories were consistent; A02 and N02 prescriptions continued to rise with age, while C10 slightly decreased in the 85+ age group in all countries.

CONCLUSIONS

The findings of this study are consistent with the major chronic diseases reported in the older European population. Evidence on co-medication of newly applied medicines with the currently identified most commonly used medicines in older people should be generated during the (non)clinical development of new medicines to support regulatory assessment and adequate user information.

A Phenomenological Exploration of the Personal Implications of Female Adolescents Living With Chronic Pain

INTRODUCTION

Chronic pain (CP) negatively impacts everyday previously taken-for-granted activities resulting in considerable psychosocial stress for the individual. Qualitative research in pediatric CP is limited despite the considerable influence CP has on the process of establishing one's personal identity during these formative years and invites the opportunity to understand how CP affects these young individuals from their perspective. The objective of the study was to inquire into the experiences of female adolescents living with CP in order to enhance our understanding of how CP affects their personal lives.

METHOD

We used an interpretive phenomenological approach; two researchers interviewed eight female patients of the Montreal Children's Hospital Chronic Pain Management Clinic (aged 14-17 years) for one session each.

RESULTS

Self-reported factors that improved these female adolescents' personal life included having engaging hobbies, accepting the incurability of CP, and envisioning a fulfilling future.

DISCUSSION

The findings from this study suggest a need to orient CP-related services around goals and interests that female adolescents living with CP set for themselves in order to improve their perceived quality of life.

AAV-Mediated Combination Gene Therapy for Neuropathic Pain: GAD65, GDNF, and IL-10

Neuropathic pain is a chronic pain state characterized by nerve damage, inflammation, and nociceptive neuron hyperactivity. As the underlying pathophysiology is complex, a more effective therapy for neuropathic pain would be one that targets multiple elements. Here, we generated recombinant adeno-associated viruses (AAVs) encoding three therapeutic genes, namely, glutamate decarboxylase 65, glial cell-derived neurotrophic factor, and interleukin-10, with various combinations. The efficacy for pain relief was evaluated in a rat spared nerve injury model of neuropathic pain. The maximal analgesic effect was achieved when the AAVs expressing all three genes were administered to rats with neuropathic pain. The combination of two virus constructs expressing the three genes was named KLS-2031 and evaluated as a potential novel therapeutic for neuropathic pain. Single transforaminal epidural injections of KLS-2031 into the intervertebral foramen to target the appropriate dorsal root ganglion produced notable long-term analgesic effects in female and male rats. Furthermore, KLS-2031 mitigated the neuroinflammation, neuronal cell death, and dorsal root ganglion hyperexcitability induced by the spared nerve injury. These results suggest that KLS-2031 represents a promising therapeutic option for refractory neuropathic pain.

Efficacy of Flurbiprofen for Postoperative Pain in Chinese Surgical Patients: A Meta-Analysis

BACKGROUND

The objective of this meta-analysis is to assess the analgesic effect of flurbiprofen on postoperative pain in Chinese surgical patients.

METHODS

The primary outcome was acute postoperative pain scores; the secondary outcomes included total opiate consumption during surgery and adverse effects, such as nausea, vomiting, and dizziness. Results were expressed as weighted mean difference (WMD) or odds ratio with 95% confidence intervals (95% CIs). We evaluated heterogeneity by visually examining the forest plots and quantified it by using the I² statistic. We used random-effects models to pool the data.

RESULTS

Of 573 abstracts reviewed, 19 studies involving 1628 participants met the inclusion criteria. Pooled results showed that the intravenous administration of flurbiprofen had a beneficial effect in reducing pain scores at 2 (WMD, -0.78; 95% CI, -1.22 to -0.34; P = 0.001), 6 (WMD, -0.93; 95% CI, -1.40 to -0.46; P = 0.000), 12 (WMD, -1.09; 95% CI, -1.93 to -0.24; P = 0.011), 24 (WMD, -1.08; 95% CI, -1.48 to -0.68; P = 0.000), and 48 (WMD, -0.62; 95% CI, -1.19 to -0.05; P = 0.032) h after surgery. In addition, flurbiprofen administration significantly decreased the incidence of postoperative nausea and vomiting (odds ratio, 0.39; 95% CI, 0.26-0.58; P = 0.000) but had no effects on opiate consumption and dizziness.

CONCLUSIONS

The perioperative administration of flurbiprofen is effective in reducing postoperative pain, nausea, and vomiting in Chinese surgical patients. Future studies with adequate power should evaluate the ideal flurbiprofen regimen for postoperative pain.

Sex-Specific Pharmacotherapy for Migraine: A Narrative Review

Migraine is a common neurological disorder characterized by recurrent headache episodes that accompany sensory-motor disturbances, such as higher sensitivity to touch and light, extremity heaviness or weakness, and speech or language disabilities. Worldwide, migraine is one of the top 10 causes of disability and hence poses a huge economic burden to society. On average, migraine occurs in 12% of population but its occurrence is sexually dimorphic, as it is two to three times more prevalent in women than in men. This female to male ratio of migraine prevalence is age- and sex hormone-dependent. Advancements in understanding migraine pathogenesis have also revealed an association with both genetics and epigenetics. The severity of migraine, in terms of its attack duration, headache intensity, frequency, and occurrence of migraine-associated symptoms, has generally been reported to be greater in women. Sex differences in migraine disability and comorbidities, such as psychiatric disorders, have also been noted in some population-based studies. However, research on sex-related differences in response to migraine treatments is relatively scarce. Although a general observation is that women consume more medication than men for migraine treatment, strategies for the use of abortive and preventive medications for migraine are generally similar in both sexes. This narrative review summarizes available findings on sexually distinct responses to abortive and prophylactic pharmacotherapy of migraine. Basic experimental data and clinical findings will be presented, and potential mechanisms underlying sex-based responses will be discussed to highlight the importance and value of sex-based treatment in migraine research and practice.

Pain thresholds and intensities of CRPS type I and neuropathic pain in respect to sex

BACKGROUND AND AIMS

Healthy women have generally been found to have increased experimental pain perception and chronic pain has a higher prevalence in female as compared to male patients. However, no study has investigated whether pain intensity and pain perception thresholds are distinct or similar between sexes within various chronic pain entities. We investigated whether average pain intensities and pain thresholds assessed using quantitative sensory testing (QST) differed between women and men suffering from three distinct chronic pain conditions: Complex Regional Pain Syndrome (CRPS type I), peripheral nerve injury (PNI) or polyneuropathy (PNP), as compared to paired healthy volunteers.

METHODS

QST data of 1,252 patients (669 female, 583 male) with PNI (n = 342), PNP (n = 571) or CRPS (n = 339), and average pain intensity reports from previously published studies were included. Absolute and z-values (adjusted for age and body region) of cold, heat, pressure (PPT) and pinprick pain thresholds were compared in generalized linear models with aetiology, duration of underlying pain disease and average pain intensity as fixed effects.

RESULTS

Average pain intensity during the past four weeks did not differ between women and men, in both mean and range. In women absolute pain thresholds for cold, heat and pinprick were lower than in males across all diagnoses (p < .05). However, after z-transformation these differences disappeared except for PPT in CRPS (p = .001).

DISCUSSION

Pain thresholds in patients show only minor sex differences. However, these differences mimic those observed in healthy subjects and do not seem to be linked to specific pathophysiological processes.

SIGNIFICANCE

Female healthy participants and female patients with neuropathic pain conditions or CRPS I report lower pain thresholds compared to males, but pain intensity is similar and there is no sex difference in the extent to which the thresholds are altered in neuropathic pain or CRPS. Thus, the sex differences observed in various chronic pain conditions mimic those obtained in healthy participants, indicating that these differences are not linked to specific pathophysiological processes and are of minor clinical relevance.

Mørch C, S. Palsson T, Boudreau SA. Modifiable motion graphics for capturing sensations

Objective

The purpose of this study was to assess the relationship between an embodied sensory experience and the ability to translate the perception of this experience visually using modifiable motion graphics.

Methods

A custom-designed software was developed to enable users to modify a motion graphic in real-time. The motion graphics were designed to depict realistic visualizations of pain quality descriptors, such as tingling and burning. Participants (N = 34) received an electrical stimulation protocol known to elicit sensations of tingling. The protocol consisted of eight stimulation intensities ranging from 2—6mA delivered, in a randomized fashion and repeated three times, to the index finger. Immediately after each stimulus, participants drew the area of the evoked sensation on a digital body chart of the hand. Participants then modified the motion graphic of tingling by adjusting two parameters, namely the speed (rate of dots disappearing and re-appearing) and density of these dots in the drawn area. Then, participants rated the perceived intensity and selected the most appropriate pain quality descriptor.

Results

There was an increase in the area, density, and perceived intensity ratings as the electrical stimulation intensity increased (P<0.001). The density of the motion graphic, but not speed, correlated with perceived intensity ratings (0.69, P<0.001) and electrical stimulation intensities (0.63, P<0.01). The descriptor ‘tingling’ was predominantly selected in the range of 3–4.5mA and was often followed by ‘stabbing’ as the electrical intensity increased.

Discussion

The motion graphic tested was perceived to reflect a tingling sensation, the stimulation protocol elicited a tingling sensation, and participants adjusted one of the two motion graphic features systematically. In conclusion, an embodied sensation, such as tingling, maybe visually represented similarly between individuals. These findings create research, clinical, and commercial opportunities that utilize psychophysics to explore, visualize, and quantify changes in embodied sensory experiences in response to known stimuli.

Differential Analgesia From Vibratory Stimulation During Local Injection of Anesthetic: A Randomized Clinical Trial

BACKGROUND

Inadequate pain reduction during anesthetic injection is a significant medical and surgical problem. Vibratory distraction reduces this pain; however, there are minimal data identifying those who respond best.

OBJECTIVE

To quantify analgesia from vibration before anesthetic injection.

MATERIALS AND METHODS

In this partially blinded, single-institution trial, adult participants were randomized to intervention (vibratory anesthetic device, VAD ON) or placebo (VAD OFF). Pain was assessed using the 11-point numeric rating scale (NRS). Relative reduction in NRS between VAD OFF and ON was used to identify minimum clinically important and substantially clinically important difference in pain.

RESULTS

One hundred one tested sites from 87 subjects were assessed. Sixty-three percent were men with a median age of 66 years. From univariate analysis, males, subjects aged <60, and head and neck (HN) treated subjects had a significant reduction in NRS (p < .05). Multivariate analysis identified NRS reductions in females <60 (p = .012), males ≥70 (p = .002), females and males treated on HN (p = .048 and p = .035, respectively), and males ≥70 treated on HN (p = .012). Substantially clinically important difference (≥57% NRS reduction) included subjects <60, females <70, HN treatment aged 60 to 69, males ≥70, and females treated on HN.

CONCLUSION

Vibratory anesthetic device reduces pain during anesthetic injection, primarily for HN treatments and older male subjects.

"Bridging the Gap" Everything that Could Have Been Avoided If We Had Applied Gender Medicine, Pharmacogenetics and Personalized Medicine in the Gender-Omics and Sex-Omics Era

Gender medicine is the first step of personalized medicine and patient-centred care, an essential development to achieve the standard goal of a holistic approach to patients and diseases. By addressing the interrelation and integration of biological markers (i.e., sex) with indicators of psychological/cultural behaviour (i.e., gender), gender medicine represents the crucial assumption for achieving the personalized health-care required in the third millennium. However, ‘sex’ and ‘gender’ are often misused as synonyms, leading to frequent misunderstandings in those who are not deeply involved in the field. Overall, we have to face the evidence that biological, genetic, epigenetic, psycho-social, cultural, and environmental factors mutually interact in defining sex/gender differences, and at the same time in establishing potential unwanted sex/gender disparities. Prioritizing the role of sex/gender in physiological and pathological processes is crucial in terms of efficient prevention, clinical signs’ identification, prognosis definition, and therapy optimization. In this regard, the omics-approach has become a powerful tool to identify sex/gender-specific disease markers, with potential benefits also in terms of socio-psychological wellbeing for each individual, and cost-effectiveness for National Healthcare systems. “Being a male or being a female” is indeed important from a health point of view and it is no longer possible to avoid “sex and gender lens” when approaching patients. Accordingly, personalized healthcare must be based on evidence from targeted research studies aimed at understanding how sex and gender influence health across the entire life span. The rapid development of genetic tools in the molecular medicine approaches and their impact in healthcare is an example of highly specialized applications that have moved from specialists to primary care providers (e.g., pharmacogenetic and pharmacogenomic applications in routine medical practice). Gender medicine needs to follow the same path and become an established medical approach. To face the genetic, molecular and pharmacological bases of the existing sex/gender gap by means of omics approaches will pave the way to the discovery and identification of novel drug-targets/therapeutic protocols, personalized laboratory tests and diagnostic procedures (sex/gender-omics). In this scenario, the aim of the present review is not to simply resume the state-of-the-art in the field, rather an opportunity to gain insights into gender medicine, spanning from molecular up to social and psychological stances. The description and critical discussion of some key selected multidisciplinary topics considered as paradigmatic of sex/gender differences and sex/gender inequalities will allow to draft and design strategies useful to fill the existing gap and move forward.

A Review of Strain and Sex Differences in Response to Pain and Analgesia in Mice

Pain and its alleviation are currently a highly studied issue in human health. Research on pain and response to analgesia has evolved to include the effects of genetics, heritability, and sex as important components in both humans and animals. The laboratory mouse is the major animal studied in the field of pain and analgesia. Studying the inbred mouse to understand how genetic heritable traits and/or sex influence pain and analgesia has added valuable information to the complex nature of pain as a human disease. In the context of biomedical research, identifying pain and ensuring its control through analgesia in research animals remains one of the hallmark responsibilities of the research community. Advancements in both human and mouse genomic research shed light not only on the need to understand how both strain and sex affect the mouse pain response but also on how these research achievements can be used to improve the humane use of all research animal species. A better understanding of how strain and sex affect the response to pain may allow researchers to improve study design and thereby the reproducibility of animal research studies. The need to use both sexes, along with an improved understanding of how genetic heritability affects nociception and analgesic sensitivity, remains a key priority for pain researchers working with mice. This review summarizes the current literature on how strain and sex alter the response to pain and analgesia in the modern research mouse, and highlights the importance of both strain and sex selection in pain research.

Epidural Analgesia With Sufentanil in Relation to OPRM1 and ABCB1 Polymorphisms

The aim of this study was to evaluate the association between OPRM1 and ABCB1 polymorphisms on pain relief with epidural sufentanil in 69 patients after rectosigma resection for cancer. The median number of injections (SD) 2.31 (1.36), IQR=1, required by 118AA subjects was significantly lower in comparison with 118AG group 5.25 (3.13), IQR=6.5, (χ2=9.75, p=0.001); correspondingly median drug consumption of 1.16 (0.79), IQR=1.083, defined daily doses (DDD) was significantly less in the 118AA group in comparison with 2.14 (1.17), IQR=2.23, DDD in 118AG subjects, (χ2=7.00, p=0.008). Opioid-induced adverse effects were observed in 15 % and 33 % of patients in 118AA and 118AG groups, respectively (χ2=8.16, p=0.004). The median number of injections (SD) required by women and men was 3.30 (2.16), IQR=2, and 2.80 (1.59), IQR=1, respectively (χ2=6.25, p=0.012). Opioid-induced adverse effects were observed in 26 % and 12 % of women and men, respectively (χ2=5.49, p=0.011). Heterozygotes of OPRM1 polymorphism and women were more difficult to treat subpopulations that required higher doses of rescue analgesic medication and suffered more adverse effects.

Pediatric postoperative opioid prescribing and the opioid crisis

PURPOSE OF REVIEW

The purpose of this review is to explore the effects of the opioid crisis on pediatric patients in the postoperative setting and provide recommendations for well-tolerated opioid prescribing practices.

RECENT FINDINGS

Opioid overdoses have increased among all age groups, predominantly related to overprescribing and accessibility of opioids in the home. Adverse risks of prescribed opioids include respiratory depression, gastrointestinal distress, accidental ingestion, intentional misuse, new chronic use, diversion to another user, and overdose. Well-tolerated opioid prescribing practices include multimodal pain management; prescribing guided by patient need; risk assessment for potential misuse; and comprehensive patient and family education on risks, safe storage, and disposal practices. Evolving state laws will affect varying institutional policies; thus, providers must ensure their prescribing practices are current and compliant.

SUMMARY

All age groups have been affected by the opioid crisis, including children and adolescents. When managing postoperative pain, clinicians must balance appropriate pain management with well-tolerated opioid stewardship to minimize harm related to postoperative care.