Research trends and hotspots of ketamine from 2014 to 2023: a bibliometric analysis.

Background: Despite this growing interest, there remains a lack of comprehensive and systematic bibliometric analyses of ketamine research. This study aimed to summarize the progress in ketamine research through bibliometric analysis, providing insights into the development and direction of the field. Methods: Publications related to ketamine were retrieved from the Web of Science Core Collection (WoSCC) database on February 15, 2024. In conducting a comprehensive bibliometric analysis, a variety of bibliographic elements were meticulously collected to map the landscape of research within a specific field. Results: Between January 1, 2014, and December 31, 2023, a total of 10,328 articles on ketamine research were published across 1,752 academic journals by 45,891 authors from 8,914 institutions in 128 countries. The publication volume has shown a steady increase over this period. The United States of America (USA) and the People's Republic of China lead in both publication and citation counts. The National Institute of Mental Health (NIMH) and Yale University emerge as the most active institutions in this research domain. Carlos Zarate of the NIH National Institute of Mental Health was noted for the highest number of significant publications and received the most co-citations. The analysis revealed key research themes including mechanism of action, adverse events, psychiatric applications, and perioperative implications. Conclusion: This study provided comprehensive bibliometric and knowledge mapping analysis of the global ketamine research landscape, offering valuable insights into the trends, key contributors, and thematic focus areas within the field. By delineating the evolution of ketamine research, this study aims to guide future scholarly endeavors and enhance our understanding of ketamine's therapeutic potential.

Analgesic Effect and Sleep Quality of Low-Dose Dexmedetomidine in Cardiac Surgical Patients After Ultrafast-Track Extubation: A Randomized Clinical Trial.

OBJECTIVE: To compare the analgesic and sleep quality effects of dexmedetomidine infusion versus placebo in patients undergoing cardiac surgery with ultra-fast track extubation. DESIGN: The randomized, double-blind clinical trial study. SETTING: At a single academic center hospital. PARTICIPANTS: We included patients aged 25 to 65 scheduled for elective cardiac surgery under general anesthesia with cardiopulmonary bypass from October 2021 to December 2022. INTERVENTION: After immediate extubation in the operating room, the patients who were allocated at first after providing their consent to either the dexmedetomidine group (Dex) or the placebo group (Placebo) received continuous infusion of dexmedetomidine (0.2 µg/kg/h) or saline for 12 hours postoperatively. MEASUREMENTS AND MAIN RESULTS: The groups' demographic and perioperative variables were not statistically significant. Total morphine consumption in milligrams at 12 and 24 hours after administered study drug, total sleep time in hours by BIS value ≤85, and sleep quality with the Richard-Campbell Sleep Questionnaire were compared. The analysis included 22 Dex and 23 Placebo patients. The consumption of morphine was not statistically different between the Dex and Placebo groups at 12 and 24 hours (p = 0.707 and p = 0.502, respectively). The Dex group had significantly longer sleep time (8.7 h [7.8, 9.5]) than the Placebo group (5.8 h [2.9, 8.5]; p = 0.007). The Dex group also exhibited better sleep quality (7.9 [6.7, 8.7] vs 6.6 [5.2, 8.0]; p = 0.038). CONCLUSIONS: Sedation with low-dose dexmedetomidine infusion for ultra-fast track extubation following cardiac surgery enhances sleep duration and quality.

Novel phenylpiperazine derivatives as potent transient receptor potential vanilloid 1 antagonists.

Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel, which is considered a highly validated target for pain perception. Repeated activation with agonists to desensitize receptors or use the antagonists can both exert analgesic effects. In this work, two series of novel phenylpiperazine derivatives were designed, synthesized, and evaluated for the in vitro receptor inhibitory activity and in vivo analgesic activity. Among them, L-21 containing sulfonylurea group was identified with potent TRPV1 antagonistic activity and analgesic activity in various pain models. At the same time, L-21 exhibited low risk of hyperthermia side effect. These results indicated that L-21 is a promising candidate for further development of novel TRPV1 antagonist to treat pain.

Removal of phenazopyridine from water, synthetic urine, and real sample by adsorption using graphene oxide: A DFT theoretical/experimental approach.

Herein, graphene oxide was used as the highly efficient phenazopyridine adsorbent from aqueous medium, synthetic, and human urine. The nanoadsorbent was characterized by different instrumental techniques. The adsorption capacity (1253.17 mg g-1) was reached at pH 5.0, using an adsorbent dosage of 0.125 g L-1 at 298 K. The Sips and Langmuir described the equilibrium data well. At the same time, the pseudo-second order was more suitable for fitting the kinetic data. Thermodynamic parameters revealed the exothermic nature of adsorption with an increase in randomness at the solid-liquid interface. The magnitude of the enthalpy variation value indicates that the process involves the physisorption phenomenon. At the same time, ab initio molecular dynamics data corroborated with the thermodynamic results, indicating that adsorbent and adsorbate establish hydrogen bonds through the amine groups (adsorbate) and hydroxyl groups on the adsorbent surface (weak interactions). Electrostatic interactions are also involved. Additionally, the adsorption assays conducted in simulated medium and human urine showed the excellent performance of adsorbent material to remove the drug in real concentrations excreted by the kidneys (removal values higher than 60%).

Protocol for a pragmatic trial of Cannabidiol (CBD) to improve chronic pain symptoms among United States Veterans.

BACKGROUND: Chronic pain affects over 100 million Americans, with a disproportionately high number being Veterans. Chronic pain is often difficult to treat and responds variably to medications, with many providing minimal relief or having adverse side effects that preclude use. Cannabidiol (CBD) has emerged as a potential treatment for chronic pain, yet research in this area remains limited, with few studies examining CBD's analgesic potential. Because Veterans have a high need for improved pain care, we designed a clinical trial to investigate CBD's effectiveness in managing chronic pain symptoms among Veterans. We aim to determine whether CBD oral solution compared to placebo study medication is associated with greater improvement in the Patient Global Impression of Change (PGIC). METHODS: We designed a randomized, double-blind, placebo-controlled, pragmatic clinical trial with 468 participants. Participants will be randomly assigned in a 1:1 ratio to receive either placebo or a CBD oral solution over a 4-week period. The trial is remote via a smartphone app and by shipping study materials, including study medication, to participants. We will compare the difference in PGIC between the CBD and placebo group after four weeks and impacts on secondary outcomes (e.g., pain severity, pain interference, anxiety, suicide ideation, and sleep disturbance). DISCUSSION: Once complete, this trial will be among the largest to date investigating the efficacy of CBD for chronic pain. Findings from this clinical trial will contribute to a greater knowledge of CBD's analgesic potential and guide further research. Given the relative availability of CBD, our findings will help elucidate the potential of an accessible option for helping to manage chronic pain among Veterans. TRIAL REGISTRATION: This protocol is registered at clinicaltrials.gov under study number NCT06213233.

Real-time analgesic efficacy and factors determining drug requirements of combined spinal-epidural analgesia for labor: a prospective cohort study.

PURPOSE: Combined spinal-epidural analgesia (CSEA) is effective but not sufficient for labor pain. This study was conducted to assess the real-time analgesic efficacy, side effects of anesthetic drug dosage, and maternal satisfaction in labor to provide reference for the optimization of labor analgesia. METHODS: This was a prospective, cohort, single-center study that included 3020 women who received CSEA for labor analgesia. The visual analogue scale (VAS) for labor pain, real-time anesthetic drug dosage, side effects, adverse labor outcomes, factors influencing average drug dosage, and maternal satisfaction with CSEA were assessed. RESULTS: Overall, the VAS labor pain score was lowest at the first hour after the anesthesia was given. After 4 h for primiparas and 3 h for multiparas, the VAS score was greater than 3 but the anesthetic drug dosage did not reach the maximum allowed dosage at the same time. The average anesthetic drug dosage was positively correlated with fever, urinary retention, uterine atony, prolonged active phase, prolonged second stage, assisted vaginal delivery, and postpartum hemorrhage. The average anesthetic drug dosage was the highest in women ≤ 20 years old, those with a body mass index (BMI) ≥ 24.9 kg/m2, and those with a primary or secondary education level. CONCLUSION: Appropriate age guidance and emphasis on education of labor analgesia, weight management during pregnancy, and real-time anesthetic dosage adjustment during labor based on VAS pain score may have positive effects on the satisfaction of labor analgesia. CLINICAL TRIAL NUMBER AND REGISTRY: Clinicaltrials.gov (ChiCTR2100051809).

In vivo and in silico elucidation of possible potential and mechanisms involved in the analgesic action of ethanolic extract of Lavandula Stoechas.

OBJECTIVES: Our research focused on plant's ethanolic extract Lavandula stoechas flower part to investigate the potential analgesic effects and possible pathways involvements. METHODS: Four experimental tests were performed on Swiss albino mice with five animals in each group at different doses (50, 100, and 200mg/kg); formalin test, tail-flick test, acetic acid-induced writhing, and hot-plate test. The opioidergic, noradrenergic, cholinergic, and K channel blockers in the analgesic actions were also carried out for the potential route involvement. KEY FINDING: The percentage inhibition for abdominal writhing's and formalin activity showed a dose-dependent manner for early and late phases reducing abdominal writhing's and time period of licking, respectively. Tail immersion and hot-plate test demonstrated a substantial and dose-dependent increase in the latency time and time period of paw liking and jumping response respectively. GC-MS showed the abundantly present compounds were octadecatrienoic acid (34.35%), n-hexadecanoic acid (12.98%). In silico analyses have revealed three compounds that had good interactions with 6y3c receptor proteins, demonstrating strong binding affinities and satisfying docking parameters. CONCLUSIONS: Overall, these studies showed that ethanolic extract of L. stoechas is an important medicinal plant, with both central and peripheral antinociceptive and analgesic activities supporting its traditional use for therapeutic purposes.

Treadmill running on neuropathic pain: via modulation of neuroinflammation.

Neuropathic pain is a type of chronic pain caused by an injury or somatosensory nervous system disease. Drugs and exercise could effectively relieve neuropathic pain, but no treatment can completely stop neuropathic pain. The integration of exercise into neuropathic pain management has attracted considerable interest in recent years, and treadmill training is the most used among exercise therapies. Neuropathic pain can be effectively treated if its mechanism is clarified. In recent years, the association between neuroinflammation and neuropathic pain has been explored. Neuroinflammation can trigger proinflammatory cytokines, activate microglia, inhibit descending pain modulatory systems, and promote the overexpression of brain-derived neurotrophic factor, which lead to the generation of neuropathic pain and hypersensitivity. Treadmill exercise can alleviate neuropathic pain mainly by regulating neuroinflammation, including inhibiting the activity of pro-inflammatory factors and over activation of microglia in the dorsal horn, regulating the expression of mu opioid receptor expression in the rostral ventromedial medulla and levels of γ-aminobutyric acid to activate the descending pain modulatory system and the overexpression of brain-derived neurotrophic factor. This article reviews and summarizes research on the effect of treadmill exercise on neuropathic pain and its role in the regulation of neuroinflammation to explore its benefits for neuropathic pain treatment.

The impact of codeine rescheduling on non-opioid analgesic use by people who regularly use codeine: a prospective cohort study.

BACKGROUND: Codeine was rescheduled in Australia to prescription only in February 2018. Initial studies reported an increase in population level paracetamol and ibuprofen sales following codeine upscheduling. However, to date no study has been able to investigate changes in non-opioid analgesic use at the individual patient level to determine if sales data reflect actual consumption patterns. AIM: To address this gap, we aimed to determine the impact of codeine rescheduling on non-opioid analgesic use in people who regularly used over-the-counter codeine, primarily for pain, prior to the rescheduling change. METHOD: We conducted a prospective cohort study with 260 participants who reported regular over-the-counter codeine consumption at cohort entry. Surveys were completed at baseline (November 2017, 3 months before rescheduling) and at 1 month (February 2018), 4 months (June 2018), and 12 months (February 2019), following rescheduling. The primary outcomes were mean daily doses of non-opioid analgesics, captured through a 7 day medication diary. RESULTS: The mean daily paracetamol dose decreased from 1754.4 mg (95% CI 1300.5-2208.3) at baseline to 1023.8 mg (95% CI 808.5-1239.1) at the final time-point (+ 12 months) (p = .009). The mean daily ibuprofen dose decreased from 305.1mg (95% CI 217.9-392.4) at baseline to 161.2 mg (95% CI 98.5-224.0) 12 months after rescheduling (p = .03). No significant change in doses of other medications remained was found. CONCLUSION: In people who regularly consumed over-the-counter codeine, doses of non-opioid analgesics either reduced or remained stable following codeine rescheduling, suggesting concerns of medication substitution or overuse following the change were not realised.

Rate and predictors of postoperative opioid use and high opioid exposure after surgery in New Zealand: a retrospective study.

BACKGROUND: Although excessive opioid use is a significant global health issue, there is a lack of literature on the prescribing patterns for postoperative opioid use and exposure after discharge among surgical patients. This study aimed to examine the rate and predictors of opioid dispensing and high opioid exposure after hospital discharge from surgery in New Zealand (NZ) between January 2007 to December 2019. METHODS: This is a retrospective population-based cohort study inclusive of all ages and surgical specialties. Data were obtained from the NZ Ministry of Health's national health databases. RESULTS: 1 781 059 patients were included in the study and 20.9% (n = 371 882) of surgical patients received opioids within 7 days after hospital discharge. From those who were dispensed with opioids after hospital discharge, 36.6% (n = 134 646) had high opioid exposure. Orthopaedic surgery (AOR 6.97; 95% CI 6.82-7.13) and history of opioid use (AOR 3.18; 95% CI 2.86-3.53) increased the odds of postoperative opioid dispensing and high opioid exposure respectively. Severe multi-morbidity burden (AOR 0.76; 95% CI 0.73-0.78) and alcohol misuse (AOR 0.84; 95% CI 0.77-0.93) lowered the odds of postoperative opioid dispensing and high opioid exposure respectively. CONCLUSIONS: Our findings suggest a concerning rate of high opioid exposure among surgical patients after discharge. The predictors for postoperative opioid dispensing and high opioid exposure identified in our study provide insight into opioid prescribing patterns in NZ and inform future postoperative pain management.

S-nitrosoglutathione reductase alleviates morphine analgesic tolerance by restricting PKCα S-nitrosation.

Morphine, a typical opiate, is widely used for controlling pain but can lead to various side effects with long-term use, including addiction, analgesic tolerance, and hyperalgesia. At present, however, the mechanisms underlying the development of morphine analgesic tolerance are not fully understood. This tolerance is influenced by various opioid receptor and kinase protein modifications, such as phosphorylation and ubiquitination. Here, we established a murine morphine tolerance model to investigate whether and how S-nitrosoglutathione reductase (GSNOR) is involved in morphine tolerance. Repeated administration of morphine resulted in the down-regulation of GSNOR, which increased excessive total protein S-nitrosation in the prefrontal cortex. Knockout or chemical inhibition of GSNOR promoted the development of morphine analgesic tolerance and neuron-specific overexpression of GSNOR alleviated morphine analgesic tolerance. Mechanistically, GSNOR deficiency enhanced S-nitrosation of cellular protein kinase alpha (PKCα) at the Cys78 and Cys132 sites, leading to inhibition of PKCα kinase activity, which ultimately promoted the development of morphine analgesic tolerance. Our study highlighted the significant role of GSNOR as a key regulator of PKCα S-nitrosation and its involvement in morphine analgesic tolerance, thus providing a potential therapeutic target for morphine tolerance.

Bispecific Sigma1R-Antagonist/MOR-Agonist Compounds for Pain.

Recent research has significantly advanced an understanding of sigma receptors, which consist of two distinct subtypes designated as S1R and S2R (s1R and s2R gene products, respectively). Both subtypes have recently been cloned and their crystal structures have been published. As a result, highly selective S1R and S2R agonist and antagonist ligands are now available. Unlike the confusion generated from prior use of non-selective 'sigma' compounds, these tool compounds have begun to add clarity about the function of sigma receptors in health and disease.  The discovery of compounds with high-affinity (nM range) S1R/S2R or S2R/S1R subtype selectivity (>100-fold), and selectivity over off-target sites (>1,000-fold) has brought the study of sigma receptor pharmacology into the modern era. Computer modeling has contributed to a better understanding of the binding processes, structural requirements for chemical synthesis, and potential therapeutic uses. Several lines of evidence converge on pain as a therapeutic target for S1R-antagonists (as single mechanism or as part of a multi-mechanistic approach). We highlight here some compounds reported over the past few years that have promise for use as analgesics, specifically some mono-mechanistic S1R-antagonists, and some that are 'bispecific', i.e., have more than one mechanism of action, for example, complementary action of the mu-opioid receptor (MOR). We concentrate on some compounds that are further along in development, in particular, some of the bispecific S1R-antagonist/MOR-agonist compounds.

Wrist-ankle acupuncture for primary dysmenorrhea: a randomized controlled trial evaluating the efficacy of an analgesic strap.

Background: Drawing on the principles of wrist-ankle acupuncture (WAA), our research team has developed a portable device for WAA point compression, termed the acupressure wrist-ankle strap (AWA). The current study aims to evaluate the efficacy of the AWA in alleviating pain associated with primary dysmenorrhea. Methods: A single-blind, randomized clinical trial was conducted from April 1, 2019, to December 31, 2019. 78 participants with primary dysmenorrhea were recruited from Shanghai University of Traditional Chinese Medicine. All participants were treated on the first day of menstruation for 30 min. Participants in the AWA group used the AWA, the internal side of which is equipped with a tip compression component, while participants in the non-acupressure wrist-ankle acupuncture(NAWA)group used the NAWA, with the inside tip pressing parts removed. The main outcome was the difference in visual analogue scale (VAS) score between baseline and 30 minutes after randomization. Results: A total of 78 participants aged 18 to 30 years were included in the intention-to-treat analyses. The VAS scores (mean [standard deviation]) in the AWA group were significantly lower than those in the NAWA group at each time point of intervention (5 minutes: 95% CI, [-1.27 to -0.68], p < 0.001; 10 minutes: 95% CI, [-2.34 to -1.51], p < 0.001; 30 minutes: 95% CI, [-3.74 to -2.72], p < 0.001). In the AWA group, 16 participants reported "obvious relief" of dysmenorrhea pain while 23 did not; the average onset time of analgesia they reported were (21.50 ± 3.65) min, while no subjects in NAWA group reported obvious pain relief. The pain threshold (mean [standard deviation]) at SP9 of both sides in AWA group decreased significantly after intervention that in NAWA group (Left: 95% CI, [-5.02 to -1.81], p < 0.001; Right: 95% CI, [-7.67 to -4.24], p < 0.001). There was no significant change in the temperature at CV4 in either group (95% CI, [-0.63 to -0.66], p = 0.970). Conclusion: This trial substantiates our hypothesis that the AWA provides immediate analgesic effects. The AWA represents an effective and safe non-invasive physical therapy option, which patients can self-administer to alleviate abdominal pain.

Postoperative analgesic consumption for primary versus first repeat Cesarean delivery: a historical cohort study.

PURPOSE: It is unclear if postoperative pain experience and opioid consumption differ in patients undergoing primary vs repeat Cesarean delivery (CD) as prior studies have yielded conflicting results and none used the same patients as their own controls. We sought to compare opioid consumption and pain scores in patients undergoing both a primary and a first repeat CD, using the same patients as their own controls. METHODS: We conducted a single-centre historical cohort study of patients who underwent both a primary and a first repeat CD under neuraxial anesthesia between 1 January 2016 and 30 November 2022. The same standardized multimodal analgesic regimen was used for all patients. The primary outcome was opioid consumption in oral morphine equivalents (OME) at 48 hr after surgery. Secondary outcomes included area under the curve for pain scores at 24 and 48 hr, and opioid consumption at 24 hr. RESULTS: We included 409 patients. In unadjusted analysis, there were no significant differences between primary and repeat CD in median [interquartile range] opioid consumption at 48 hr (45 [15-89] mg vs 45 [15-83] mg OME) or in any of the secondary outcomes. In the multivariable model adjusting for age, body mass index, anxiety, depression, priority, surgery duration, gestational age, receipt of postoperative ketorolac, and neuraxial type, repeat CD was still not associated with increased opioid consumption compared with primary CD (adjusted rate ratio, 1.20; 95% confidence interval, 0.95 to 1.51). CONCLUSION: In this retrospective study, we found no differences in postoperative opioid consumption or reported pain scores in patients who underwent both a primary and a first repeat CD.

RéSUMé: OBJECTIF: Nous ne savons pas si l'expérience de la douleur postopératoire et la consommation d'opioïdes diffèrent chez la patientèle accouchant par césarienne pour la première fois ou pour la seconde fois. En effet, les études antérieures ont donné des résultats contradictoires et aucune n'a utilisé la même patientèle comme témoins. Nous avons cherché à comparer la consommation d'opioïdes et les scores de douleur chez les personnes parturientes exposées à la fois à un premier puis un deuxième accouchement par césarienne en recrutant les mêmes personnes en tant que leurs propres témoins. MéTHODE: Nous avons mené une étude de cohorte historique monocentrique auprès de personnes parturientes ayant subi à la fois une première et une seconde césarienne sous anesthésie neuraxiale entre le 1er janvier 2016 et le 30 novembre 2022. Le même régime analgésique multimodal standardisé a été utilisé pour toutes les personnes dans l'étude. Le critère d'évaluation principal était la consommation d'opioïdes en équivalents morphine oraux (EMO) 48 heures après la chirurgie. Les critères d'évaluation secondaires comprenaient la surface sous la courbe pour les scores de douleur à 24 et 48 heures, et la consommation d'opioïdes à 24 heures. RéSULTATS: Nous avons inclus 409 personnes. Dans l'analyse non ajustée, il n'y avait pas de différence significative entre le premier et le deuxième accouchement par césarienne en ce qui concerne la consommation médiane d'opioïdes [écart interquartile] à 48 heures (45 [15 à 89] mg vs 45 [15­83] mg EMO) ou dans l'un des critères d'évaluation secondaires. Dans le modèle multivarié ajusté en fonction de l'âge, l'indice de masse corporelle, l'anxiété, la dépression, la priorité, la durée de la chirurgie, l'âge gestationnel, l'administration de kétorolac postopératoire et le type d'anesthésie neuraxiale, une deuxième césarienne n'était toujours pas associée à une consommation accrue d'opioïdes par rapport à une première césarienne (rapport de taux ajusté, 1,20; intervalle de confiance à 95 %, 0,95 à 1,51). CONCLUSION: Dans cette étude rétrospective, nous n'avons trouvé aucune différence dans la consommation d'opioïdes postopératoires ou les scores de douleur rapportés chez la patientèle ayant accouché par césarienne pour la première ou pour la deuxième fois.

The Analgesic Effect of Ultrasound-guided Erector Spinae Plane Block in Median Sternotomy Cardiac Surgery in Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVES: To assess the analgesic effect of erector spinae plane block in adults undergoing median sternotomy cardiac surgery. DESIGN AND SETTING: The Cochrane, Embase, and PubMed databases from inception to January 2024 were searched. The study has been registered in the International Prospective Register of Systematic Reviews (CRD42023470375). PARTICIPANTS: Eight randomized controlled trials involving 543 patients, comparing with no block or sham block, were included, whether it was a single injection or continuous. MEASUREMENTS AND MAIN RESULTS: The primary outcomes were pain scores and opioid consumption. Erector spinae plane block reduced pain scores immediately after extubation (mean difference [MD], -1.19; 95% confidence interval [CI], -1.67 to -0.71; p for heterogeneity = 0.10), at 6 hours after extubation (MD, -1.96; 95% CI, -2.85 to -1.08; p for heterogeneity < 0.0001), and at 12 hours after extubation (MD, -0.98; 95% CI, -1.55 to -0.40; p for heterogeneity < 0.00001). The decrease in pain scores reached the minimal clinically important difference within 6 hours. Opioid consumption 24 hours after surgery decreased by 35.72 mg of oral morphine equivalents (95% CI, -50.88 to -20.57; p for heterogeneity < 0.0001). Sensitivity analysis confirmed the stability of results. The quality of primary outcomes was rated as very low to moderate. CONCLUSIONS: Erector spinae plane block decreased pain scores within 12 hours after extubation, reached the minimal clinically important difference within 6 hours, and decreased opioid consumption 24 hours after surgery, based on data of very low to moderate quality. However, high-quality randomized controlled trials are necessary to validate these findings.

Use of CYP2D6 substrates and inhibitors during pain management with analgesic opioids: Drug-drug interactions that lead to lack of analgesic effectiveness.

BACKGROUND: Several opioids have pharmacogenetic and drug-drug interactions which may compromise their analgesic effectiveness, but are not routinely implemented into supportive pain management. We hypothesized that CYP2D6 phenotypes and concomitant use of CYP2D6 substrates or inhibitors would correlate with opioid analgesic outcomes. MATERIALS AND METHODS: An observational cross-sectional study was conducted with 263 adult chronic non cancer pain (CNCP) patients from a real-world pain unit under long-term CYP2D6-related opioid treatment (tramadol, hydromorphone, tapentadol or oxycodone). Metabolizer phenotype (ultrarapid [UM], normal [NM], intermediate [IM] or poor [PM]) was determined by the CYP2D6 genotype. The socio-demographic (sex, age, employment status), clinical (pain intensity and relief, neuropathic component, quality of life, disability, anxiety and depression), pharmacological (opioid doses and concomitant pharmacotherapy) and safety (adverse events) variables were recorded. RESULTS: The whole population (66 % female, 65 (14) years old, 70 % retired and 63 % attended for low back pain) were classified as PM (5 %), IM (32 %), NM (56 %) and UM (6 %). Multiple linear and logistic regressions showed higher pain intensity and neuropathic component at younger ages when using any CYP2D6 substrate (p = 0.022) or inhibitor (p = 0.030) drug, respectively, with poorer pain relief when CYP2D6 inhibitors (p=0.030) were present. CONCLUSION: The concomitant use of CYP2D6 substrates or inhibitors during opioid therapy for CNCP may result in lack of analgesic effectiveness. This aspect could be relevant for pharmacological decision making during CNCP management.

Analgesic eluting bone cement: A novel approach for targeted pain management in total knee arthroplasty - An in-vitro study.

BACKGROUND: The average rate of patient dissatisfaction following total knee arthroplasty (TKA) is 10%. Multi-modal analgesia is the present standard of pain management after TKA. Studies show that with multi-modal analgesia, approximately 60% of patients experience severe knee pain following surgery, while around 30% experience moderate pain. To date, there is no literature available on targeted pain management using bone cement. OBJECTIVES: To investigate the feasibility of incorporating anti-inflammatory medications and identify the analgesic with the best release pharmacokinetics from bone cement for application in pain management. METHODS: In an in-vitro study, 100 mg of five drugs (aceclofenac, diclofenac, naproxen, paracetamol and methyl prednisolone) were incorporated into bone cement (Palacos). Cement cubes holding each drug were made and allowed to harden for 30 min. Each drug-containing cube was placed in a beaker with saline for 72 h. Fractions of 10 ml were collected at 0, 6, 24, 48 and 72 h and analysed using high-pressure liquid chromatography to measure the percentage release of the drug from bone cement. RESULTS: Naproxen showed superior elution from bone cement, with 10.9% at 24 h and 9.08% at 72 h. Paracetamol showed 4.9% at 24 h and 3.78% at 72 h, aceclofenac 0.2% at 24 h and 0.4% at 72 h, diclofenac 3.03% at 24 h and 1.99% at 72 h, and methylprednisolone 0.26% at 24 h and 0.32% at 72 h. CONCLUSIONS: Polymethylmethacrylate bone cement can elute analgesics in vitro. Among the five drugs studied, naproxen had the best release kinematics from polymethylmethacrylate bone cement. Analgesic eluting bone cement is a novel approach for targeted postoperative pain management in TKA.

Perioperative cyclooxygenase inhibition and postoperative pancreatic fistula after pancreatoduodenectomy: A systematic review and meta-analysis of comparative studies.

BACKGROUND: Nonsteroidal anti-inflammatory drug (NSAID) use has been investigated as a modifiable risk factor for postoperative pancreatic fistula (POPF) after pancreatoduodenectomy (PD). This study comprises a systematic review and meta-analysis examining the impact of perioperative NSAID use on rates of POPF after PD. METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020-compliant systematic review was performed. Pooled mean differences (MD), odds ratios (OR), and risk ratios with 95% CIs were calculated. RESULTS: Seven studies published from 2015 to 2021 were included, reporting 2851 PDs (1372 receiving NSAIDs and 1479 not receiving NSAIDs). There were no differences regarding blood loss (MD -99.40 mL; 95% CI, -201.71 to 2.91; P = .06), overall morbidity (OR 1.05; 95% CI, 0.68-1.61; P = .83), hemorrhage (OR 2.35; 95% CI, 0.48-11.59; P = .29), delayed gastric emptying (OR 0.98; 95% CI, 0.60-1.60; P = .93), bile leak (OR 0.68; 95% CI, 0.12-3.89; P = .66), surgical site infection (OR 1.02; 95% CI, 0.33-3.22; P = .97), abscess (OR 0.99; 95% CI, 0.51-1.91; P = .97), clinically relevant POPF (OR 1.18; 95% CI, 0.84-1.64; P = .33), readmission (OR 0.94; 95% CI, 0.61-1.46; P = .78), or reoperation (OR 0.82; 95% CI, 0.33-2.06; P = .68). NSAID use was associated with a shorter hospital stay (MD -1.05 days; 95% CI, -1.39 to 0.71; P < .00001). CONCLUSION: The use of NSAIDs in the perioperative period for patients undergoing PD was not associated with increased rates of POPF.

In vivo analgesic, anti-inflammatory, sedative, muscle relaxant activities, and docking studies of 3',4',7,8-tetrahydroxy-3-methoxyflavone isolated from Pistacia chinensis.

Background: Pistacia chinensis is extensively employed in traditional medicine. This study aimed to isolate and evaluate the therapeutic effects of 3'4'78-tetrahydroxy-3-methoxyflavone from P. chinensis crude extract. Materials and Methods: The study utilized column chromatography for isolation. The plant extract and its isolated compound were assessed for in vivo analgesic (hot plate model), anti-inflammatory (carrageenan-induced paw edema), sedative (open field model), and muscle relaxing properties (inclined plane and traction test). Results: In the thermal-induced analgesic model, a significant analgesic effect was observed for the extract (25, 50, and 100 mg/kg) and the isolated compound (2.5, 5, 10, and 15 mg/kg) at higher doses. The extract (100 mg/kg) significantly prolonged latency time (21.98 seconds) after 120 minutes of administration. The isolated compound elevated the latency time (20.03 seconds) after 30 minutes, remaining significant up to 120 minutes with a latency time of 24.11 seconds. The anti-inflammatory effect showed a reduction in inflammatory reactions by 50.23% (extract) and 67.09% (compound) after the fifth hour of treatment. Both samples demonstrated significant sedative effects, with the extract hindering movement by 54.11 lines crossed compared to the negative control (180.99 lines). The isolated compound reduced the number of lines crossed to 15.23±SEM compared to the negative control. Both samples were also significant muscle relaxants. Docking studies indicated that the compound's therapeutic effect is due to inhibiting COX and nociceptive pathways. Conclusion: The isolated compound from Pistacia chinensis exhibits significant analgesic, anti-inflammatory, sedative, and muscle relaxing properties, with potential therapeutic applications by inhibiting COX and nociceptive pathways.

Functional infrared thermography imaging can be used to assess the effectiveness of Maxicam Gel® in pre-emptively treating transient synovitis and lameness in horses.

Introduction: Diagnosing and treating lameness in horses is essential to improving their welfare. In equine orthopedic practice, infrared thermography (IRT) can indirectly detect soreness. Non-steroidal anti-inflammatory drugs can treat painful and inflammatory processes in horses. Using IRT, the efficacy of meloxicam (Maxicam Gel®) was evaluated in pre-treating transient synovitis in horses induced by a middle carpal joint injection of lipopolysaccharides (LPS) from E. coli 055:B5 at a dose of 10 endotoxin units. Methods: In a cross-over design, six healthy horses were randomly assigned to receive either 0.6 mg/kg of oral Maxicam Gel® (MAXVO) or a mock administration (control group, C) following a two-week washout period. IRT of the middle carpal joint, visual lameness assessment and joint circumference were recorded over time. Clinical and hematological evaluations were performed. Synovial fluid aspirates were analyzed for total nucleated cell count, total protein, and prostaglandin E2. A mixed effects analysis of variance was performed for repeated measures over time, followed by Tukey's test. A multinomial logistic regression was conducted to determine whether there is a relationship between a thermography temperature change and the lameness score. Results: There were no changes in joint circumference. The MAXVO group showed a lower rectal temperature 4 h after synovitis induction. The C group presented an increase in neutrophils and a decrease in total hemoglobin and hematocrit 8 h after induction. No changes were observed in the synovial fluid between groups. The horses that received meloxicam did not show clinically significant lameness at any time, while the C group showed an increase in lameness 2, 4, and 8 h after synovitis induction. Discussion: IRT indicated that the skin surface temperature of the middle carpal joint was lower in horses who received meloxicam, suggesting a reduction in the inflammatory process induced by LPS. It was observed that the maximum temperature peaks in the dorsopalmar and lateropalmar positions can be utilized to predict the severity of lameness, particularly when the temperature rises above 34°C. Horses pre-treated with meloxicam showed either reduced or no indication of mild to moderate pain and presented a lowehr thermographic temperature, which indicates the effectiveness of Maxicam Gel® as an anti-inflammatory.