[Source Apportionment of Morphine in Wastewater]

It is a new approach to identify legal or illegal use of morphine through information on municipal wastewater. However, the sources of morphine in wastewater are complex, and distinguishing the contribution of different sources has become a key issue. A total of 262 influent samples from 61 representative wastewater treatment plants in a typical city were collected from October 2022 to March 2023. The concentrations of morphine, codeine, thebaine, papaverine, noscapine, and monoacetylmorphine were analyzed in wastewater and poppy straws. Combined with the proportion of alkaloids in poppy straws, the source analysis of alkaloids in wastewater was analyzed using the ratio method and positive matrix factorization model (PMF). Only five alkaloids were detected in wastewater, and monoacetylmorphine, a metabolite of heroin, was not detected. The concentrations of morphine and codeine were significantly higher than those of noscapine, papaverine, and thebaine. By constructing the ratios of codeine/(morphine + codeine) and noscapine/(noscapine + codeine), the source of poppy straw could be qualitatively distinguished. The PMF results showed that three sources of morphine for medical use, poppy straw, and codeine contributed 44.9%, 43.7%, and 9.4%, respectively. The different sources varied in these months due to the COVID-19 and influenza A outbreaks, in which the use of drugs containing poppy straws and codeine was the main source, whereas the use of morphine analgesics remained relatively stable. Inventory analysis further demonstrated the reliability of the source contributions from the PMF model, and morphine was not abused in this city.

Effectiveness of opioid switching for dyspnea and its predictors in cancer patients: a single-center retrospective observational study

BACKGROUND

Morphine is the most used opioid for dyspnea, but other opioids such as oxycodone and fentanyl are increasingly used, and opioid switching to these is sometimes undertaken. No studies have verified the effectiveness of opioid switching for relief of dyspnea. We retrospectively investigated the effectiveness of opioid switching for dyspnea and its predictors.

METHODS

All patients with opioid switching for dyspnea during hospitalization at Komaki City Hospital from January 2019 to August 2022 were included. Opioid switching was defined as a change to another opioid, and the assessment period for evaluating the effectiveness and adverse events of opioid switching was set as 1 week. Patients with Numeric Rating Scale or Japanese version of the Support Team Assessment Schedule reduction for dyspnea of at least 1, or with clear improvement based on medical records, were considered valid. Mitigating factors for dyspnea were identified using logistic regression analysis.

RESULTS

Of the 976 patients with opioid switching, 57 patients had opioid switching for relief of dyspnea. Of these, opioid switching was effective in 21 patients (36.8%). In a multivariate analysis, older patients (odds ratio: 5.52, 95% CI: 1.50-20.20, P < 0.01), short prognosis for post-opioid switching (odds ratio: 0.20, 95% CI: 0.04-0.87, P = 0.03) and cachexia (odds ratio: 0.12, 95% CI: 0.02-0.64, P < 0.01) were significantly associated with opioid switching effects for dyspnea. There were no serious adverse events after opioid switching.

CONCLUSION

This study indicates that opioid switching for dyspnea may have some effect. Furthermore, opioid switching for dyspnea may be more effective in older patients and less effective in terminally ill patients or in those with cachexia.

Repeated Morphine Exposure Alters Temporoamonic-CA1 Synaptic Plasticity in Male Rat Hippocampus

In this study, the electrophysiological and biochemical consequences of repeated exposure to morphine in male rats on glutamatergic synaptic transmission, synaptic plasticity, the expression of GABA receptors and glutamate receptors at the temporoammonic-CA1 synapse along the longitudinal axis of the hippocampus (dorsal, intermediate, ventral, DH, IH, VH, respectively) were investigated. Slice electrophysiological methods, qRT-PCR, and western blotting techniques were used to characterize synaptic plasticity properties. We showed that repeated morphine exposure (RME) reduced excitatory synaptic transmission and ability for long-term potentiation (LTP) in the VH as well as eliminated the dorsoventral difference in paired-pulse responses. A decreased expression of NR2B subunit in the VH and an increased expression GABAA receptor of α1 and α5 subunits in the DH were observed following RME. Furthermore, RME did not affect the expression of NR2A, AMPA receptor subunits, and γ2GABAA and GABAB receptors in either segment of the hippocampus. In sum, the impact of morphine may differ depending on the region of the hippocampus studied. A distinct change in the short- and long-term synaptic plasticity along the hippocampus long axis due to repeated morphine exposure, partially mediated by a change in the expression profile of glutamatergic receptor subunits. These findings can be useful in further understanding the cellular mechanism underlying deficits in information storage and, more generally, cognitive processes resulting from chronic opioid abuse.

Minimal important difference in postoperative morphine consumption after hip and knee arthroplasty using nausea, vomiting, sedation and dizziness as anchors

BACKGROUND

Morphine-sparing effects are often used to evaluate non-opioid analgesic interventions. The exact effect that would warrant the implementation of these interventions in clinical practice (a minimally important difference) remains unclear. We aimed to determine this with anchor-based methods.

METHODS

This was a post hoc analysis of three studies investigating pain management after hip or knee arthroplasty (PANSAID [NCT02571361], DEX-2-TKA [NCT03506789] and Pain Map [NCT02340052]). The overall population was median aged 70, median ASA 2, 54% female. We examined the correlation between 0 and 24 h postoperative iv morphine equivalent consumption and the severity of nausea, vomiting, sedation and dizziness. The anchor was different severity degrees of these opioid-related adverse events. The primary outcome was the difference in morphine consumption between patients experiencing no versus only mild events. Secondary outcomes included the difference in morphine consumption between patients with mild versus moderate and moderate versus severe events. We used Hodges-Lehmann median differences, exact Wilcoxon-Mann-Whitney tests and quantile regression.

RESULTS

The difference in iv morphine consumption was 6 mg (95% confidence interval: 4-8) between patients with no versus only mild events, 5 mg (2-8) between patients with mild versus moderate events and 0 mg (-4 to 4) between patients with moderate versus severe events.

CONCLUSIONS

In populations comparable to this post-hoc analysis (orthopaedic surgery, median age 70 and ASA 2), we suggest a minimally important difference of 5 mg for 0-24 h postoperative iv morphine consumption.

Biological sex influences sleep phenotype in mice experiencing spontaneous opioid withdrawal

Aversive symptoms, including insomnia experienced during opioid withdrawal, are a major drive to relapse; however, withdrawal-associated sleep symptomatology has been little explored in preclinical models. We describe here a model of opioid withdrawal in mice that resembles the sleep phenotype characteristic of withdrawal in humans. Male and female C57BL/6 mice were instrumented with telemeters to record electroencephalogram, electromyogram, activity and subcutaneous temperature. All mice received two treatments separated by a 16-day washout period: (1) saline (volume: 10 ml kg-1); or (2) ascending doses of morphine (5, 10, 20, 40 and 80 mg kg-1; volume: 10 ml kg-1) for 5 days at Zeitgeber time 1 and Zeitgeber time 13. Recordings for the first 71 hr after treatment discontinuation (withdrawal days 1-3) and for 24 hr on withdrawal days 5 and 7 were scored for sleep/wake state, and sleep architecture and electroencephalogram spectral data were analysed. Morphine was acutely wake- and activity-promoting, and non-rapid eye movement and rapid eye movement sleep were increased during the dark phase on withdrawal day 2 in both sexes. While non-rapid eye movement delta power (0.5-4.0 Hz), a measure of sleep intensity, was reduced during the light phase on withdrawal day 1 and the dark phase on withdrawal day 2 in both sexes, female mice also exhibited changes in the duration and the number of bouts of sleep/wake states. These observations of fragmented sleep on withdrawal days 1-3 suggest poorer sleep consolidation and a more pronounced withdrawal-associated sleep phenotype in female than in male mice. These data may indicate a greater sensitivity to morphine, a more distinct aversive sleep phenotype and/or a faster escalation to dependence in female mice.

Gastrointestinal adverse effects associated with the use of intravenous oliceridine compared with intravenous hydromorphone or fentanyl in acute pain management utilizing adjusted indirect treatment comparison methods

Background: In the absence of head-to-head comparative data from randomized controlled trials, indirect treatment comparisons (ITCs) may be used to compare the relative effects of treatments versus a common comparator (either placebo or active treatment). For acute pain management, the effects of oliceridine have been compared in clinical trials to morphine but not to fentanyl or hydromorphone. Aim: To assess the comparative safety (specifically differences in the incidence of nausea, vomiting and opioid-induced respiratory depression [OIRD]) between oliceridine and relevant comparators (fentanyl and hydromorphone) through ITC analysis. Methods: A systematic literature review identified randomized clinical trials with oliceridine versus morphine and morphine versus fentanyl or hydromorphone. The ITC utilized the common active comparator, morphine, for the analysis. Results: A total of six randomized controlled trials (oliceridine - 2; hydromorphone - 3; fentanyl - 1) were identified for data to be used in the ITC analyses. The oliceridine data were reported in two studies (plastic surgery and orthopedic surgery) and were also reported in a pooled analysis. The ITC focused on nausea and vomiting due to limited data for OIRD. When oliceridine was compared with hydromorphone in the ITC analysis, oliceridine significantly reduced the incidence of nausea and/or vomiting requiring antiemetics compared with hydromorphone (both orthopedic surgery and pooled data), while results in plastic surgery were not statistically significant. When oliceridine was compared with hydromorphone utilizing data from Hong, the ITC only showed a trend toward reduced risk of nausea and vomiting with oliceridine that was not statistically significant across all three comparisons (orthopedic surgery, plastic surgery and combined). An ITC comparing oliceridine with a study of fentanyl utilizing the oliceridine orthopedic surgery data and combined orthopedic and plastic surgery data showed a trend toward reduced risk that was not statistically significant. Conclusion: In ITC analyses, oliceridine significantly reduced the incidence of nausea and/or vomiting or the need for antiemetics in orthopedic surgery compared with hydromorphone and a non-significant trend toward reduced risk versus fentanyl.

Behavioral and pharmacological characterization of planarian nociception

Introduction

Pain mostly arises because specialized cells called nociceptors detect harmful or potentially harmful stimuli. In lower animals with less convoluted nervous system, these responses are believed to be purely nociceptive. Amongst invertebrate animal models, planarians are becoming popular in a wide range of pharmacological and behavioral studies beyond the field of regeneration. Recent publications led the way on pain studies by focusing on nociceptive behaviors such as the 'scrunching' gait displayed under various noxious stimuli, as opposed to the 'gliding' gait planarians usually adopt in normal conditions.

Methods

In this study, we adapted commonly used nociceptive tests to further explore nociception in planarians of the species Girardia dorotocephala. By using behavioral analysis in open fields and place preferences, we managed to set up chemical, thermal and mechanical nociceptive tests. We also adapted RNA interference protocols and explored the effects of knocking down TRPA1 ion channels, one of the main effectors of chemically and thermally-induced nociceptive responses in vertebrates.

Results

Consequently, we demonstrated the reliability of the scrunching gait in this planarian species, which they displayed in a dose-dependent manner when exposed to the irritant AITC. We also showed that suppressing the expression of TRPA1 ion channels completely suppressed the scrunching gait, demonstrating the involvement of TRPA1 nociceptors in this nociceptive reaction. Besides, we also explored the effects of two common analgesics that both displayed strong antinociceptive properties. First, morphine reduced the chemically-induced nociceptive scrunching gaits by more than 20% and shifted the E C 50 of the dose-response curve by approximately 10 μM. Secondly, the NSAID meloxicam drastically reduced chemically-induced scrunching by up to 60% and reduced heat avoidance in place preference tests.

Discussion

Thus, we managed to characterize both behavioral and pharmacological aspects of G. dorotocephala's nociception, further developing the use of planarians as a replacement model in pain studies and more globally the study of invertebrate nociception.

Advances in animal models of prenatal opioid exposure

Neonatal opioid withdrawal syndrome (NOWS) is a growing public health concern. The complexity of in utero opioid exposure in clinical studies makes it difficult to investigate underlying mechanisms that could ultimately inform early diagnosis and treatments. Clinical studies are unable to dissociate the influence of maternal polypharmacy or the environment from direct effects of in utero opioid exposure, highlighting the need for effective animal models. Early animal models of prenatal opioid exposure primarily used the prototypical opioid, morphine, and opioid exposure that was often limited to a narrow period during gestation. In recent years, the number of preclinical studies has grown rapidly. Newer models utilize both prescription and nonprescription opioids and vary the onset and duration of opioid exposure. In this review, we summarize novel prenatal opioid exposure models developed in recent years and attempt to reconcile results between studies while critically identifying gaps within the current literature.

The role of morphine- and fentanyl-induced impairment of intestinal epithelial antibacterial activity in dysbiosis and its impact on the microbiota-gut-brain axis

Recent evidence suggests that chronic exposure to opioid analgesics such as morphine disrupts the intestinal epithelial layer and causes intestinal dysbiosis. Depleting gut bacteria can preclude the development of tolerance to opioid-induced antinociception, suggesting an important role of the gut-brain axis in mediating opioid effects. The mechanism underlying opioid-induced dysbiosis, however, remains unclear. Host-produced antimicrobial peptides (AMPs) are critical for the integrity of the intestinal epithelial barrier as they prevent the pathogenesis of the enteric microbiota. Here, we report that chronic morphine or fentanyl exposure reduces the antimicrobial activity in the ileum, resulting in changes in the composition of bacteria. Fecal samples from morphine-treated mice had increased levels of Akkermansia muciniphila with a shift in the abundance ratio of Firmicutes and Bacteroidetes. Fecal microbial transplant (FMT) from morphine-naïve mice or oral supplementation with butyrate restored (a) the antimicrobial activity, (b) the expression of the antimicrobial peptide, Reg3γ, (c) prevented the increase in intestinal permeability and (d) prevented the development of antinociceptive tolerance in morphine-dependent mice. Improved epithelial barrier function with FMT or butyrate prevented the enrichment of the mucin-degrading A. muciniphila in morphine-dependent mice. These data implicate impairment of the antimicrobial activity of the intestinal epithelium as a mechanism by which opioids disrupt the microbiota-gut-brain axis.

Long-term administration of morphine specifically alters the level of protein expression in different brain regions and affects the redox state

We investigated the changes in redox state and protein expression in selected parts of the rat brain induced by a 4 week administration of morphine (10 mg/kg/day). We found a significant reduction in lipid peroxidation that mostly persisted for 1 week after morphine withdrawal. Morphine treatment led to a significant increase in complex II in the cerebral cortex (Crt), which was accompanied by increased protein carbonylation, in contrast to the other brain regions studied. Glutathione levels were altered differently in the different brain regions after morphine treatment. Using label-free quantitative proteomic analysis, we found some specific changes in protein expression profiles in the Crt, hippocampus, striatum, and cerebellum on the day after morphine withdrawal and 1 week later. A common feature was the upregulation of anti-apoptotic proteins and dysregulation of the extracellular matrix. Our results indicate that the tested protocol of morphine administration has no significant toxic effect on the rat brain. On the contrary, it led to a decrease in lipid peroxidation and activation of anti-apoptotic proteins. Furthermore, our data suggest that long-term treatment with morphine acts specifically on different brain regions and that a 1 week drug withdrawal is not sufficient to normalize cellular redox state and protein levels.

Gut dysbiosis was inevitable, but tolerance was not: temporal responses of the murine microbiota that maintain its capacity for butyrate production correlate with sustained antinociception to chronic voluntary morphine

The therapeutic benefits of opioids are compromised by the development of analgesic tolerance, which necessitates higher dosing for pain management thereby increasing the liability for dependence and addiction. Rodent models indicate opposing roles of the gut microbiota in tolerance: morphine-induced gut dysbiosis exacerbates tolerance, whereas probiotics ameliorate tolerance. Not all individuals develop tolerance which could be influenced by differences in microbiota, and yet no study has capitalized upon this natural variation to identify specific features linked to tolerance. We leveraged this natural variation in a murine model of voluntary oral morphine self-administration to elucidate the mechanisms by which microbiota influences tolerance. Although all mice shared similar and predictive morphine-driven microbiota changes that largely masked informative associations with variability in tolerance, our high-resolution temporal analyses revealed a divergence in the progression of dysbiosis that best explained differences in the development in tolerance. Mice that did not develop tolerance also maintained a higher abundance of taxa capable of producing the short-chain fatty acid (SCFA) butyrate, known to bolster intestinal barriers, suppress inflammation, and promote neuronal homeostasis. Furthermore, dietary butyrate supplementation significantly reduced the development of tolerance. These findings could inform immediate therapies to extend the analgesic efficacy of opioids.

PBPK-PD model for predicting morphine pharmacokinetics, CNS effects and naloxone antagonism in humans

Morphine and morphine-6-glucuronide (M6G) produce central nervous system (CNS) effects by activating mu-opioid receptors, while naloxone is used mainly for the reversal of opioid overdose, specifically for the fatal complication of respiratory depression, but also for alleviating opioid-induced side effects. In this study we developed a physiologically-based pharmacokinetic-pharmacodynamic (PBPK-PD) model to simultaneously predict pharmacokinetics and CNS effects (miosis, respiratory depression and analgesia) of morphine as well as antagonistic effects of naloxone against morphine. The pharmacokinetic and pharmacodynamic parameters were obtained from in vitro data, in silico, or animals. Pharmacokinetic and pharmacodynamic simulations were conducted using 39 and 36 clinical reports, respectively. The pharmacokinetics of morphine and M6G following oral or intravenous administration were simulated, and the PBPK-PD model was validated using clinical observations. The Emax model correlated CNS effects with free concentrations of morphine and M6G in brain parenchyma. The predicted CNS effects were compared with observations. Most clinical observations fell within the 5th-95th percentiles of simulations based on 1000 virtual individuals. Most of the simulated area under the concentration-time curve or peak concentrations also fell within 0.5-2-fold of observations. The contribution of morphine to CNS effects following intravenous or oral administration was larger than that of M6G. Pharmacokinetics and antagonistic effects of naloxone on CNS effects were also successfully predicted using the developed PBPK-PD model. In conclusion, the pharmacokinetics and pharmacodynamics of morphine and M6G, antagonistic effects of naloxone against morphine-induced CNS effects may be successfully predicted using the developed PBPK-PD model based on the parameters derived from in vitro, in silico, or animal studies.

Cannabinoid-Induced Inhibition of Morphine Glucuronidation and the Potential for In Vivo Drug-Drug Interactions

Opioids are commonly prescribed for the treatment of chronic pain. Approximately 50% of adults who are prescribed opioids for pain co-use cannabis with their opioid treatment. Morphine is primarily metabolized by UDP-glucuronosyltransferase (UGT) 2B7 to an inactive metabolite, morphine-3-glucuronide (M3G), and an active metabolite, morphine-6-glucuronide (M6G). Previous studies have shown that major cannabis constituents including Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) inhibit major UGT enzymes. To examine whether cannabinoids or their major metabolites inhibit morphine glucuronidation by UGT2B7, in vitro assays and mechanistic static modeling were performed with these cannabinoids and their major metabolites including 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (11-COOH-THC), 7-hydroxy-cannabidiol (7-OH-CBD), and 7-carboxy-cannabidiol (7-COOH-CBD). In vitro assays with rUGT-overexpressing microsomes and human liver microsomes showed that THC and CBD and their metabolites inhibited UGT2B7-mediated morphine metabolism, with CBD and THC exhibiting the most potent Ki,u values (0.16 µM and 0.37 µM, respectively). Only 7-COOH-CBD exhibited no inhibitory activity against UGT2B7-mediated morphine metabolism. Static mechanistic modeling predicted an in vivo drug-drug interaction between morphine and THC after inhaled cannabis, and between THC, CBD, and 7-OH-CBD after oral consumption of cannabis. These data suggest that the co-use of these agents may lead to adverse drug events in humans.

Low-Dose Morphine Does Not Cause Sleepiness in COPD: A Secondary Analysis of a Randomized Trial

RATIONALE

Regular, low-dose, sustained-release morphine is frequently prescribed for persistent breathlessness in chronic obstructive pulmonary disease (COPD). However, effects on daytime sleepiness, perceived sleep quality and daytime function have not been rigorously investigated.

OBJECTIVES

Determine the effects of regular, low-dose, sustained-release morphine on sleep parameters in COPD.

METHODS

Pre-specified secondary analyses of validated sleep questionnaire data from a randomized trial of daily, low-dose, sustained -release morphine versus placebo over four weeks commencing at 8mg or 16mg/day with blinded up-titration over two weeks to a maximum of 32mg/day. Primary outcomes for these analyses were week-1 Epworth Sleepiness Scale (ESS) and Karolinska Sleepiness Scale (KSS) responses on morphine versus placebo. Secondary outcomes included Leeds Sleep Evaluation Questionnaire (LSEQ) scores (end of weeks 1 and 4), KSS and ESS beyond week-1 and associations between breathlessness, morphine, and questionnaire scores.

MEASUREMENTS AND MAIN RESULTS

156 people were randomized. Week-1 sleepiness scores were not different on morphine versus placebo (∆ESS [95%CI] versus placebo: 8mg group: -0.59 [-1.99, 0.81], p=0.41; 16mg group: -0.72 [-2.33, 0.9], p=0.38; ∆KSS versus placebo: 8mg group: 0.11 [-0.7, 0.9], p=0.78; 16mg group: -0.41 [-1.31, 0.49], p=0.37). This neutral effect persisted at later timepoints. In addition, participants who reported reduced breathlessness with morphine at 4 weeks also had improvement in LSEQ domain scores including perceived sleep quality and daytime function.

CONCLUSIONS

Regular, low-dose morphine does not worsen sleepiness when used for breathlessness in COPD. Individual improvements in breathlessness with morphine may be related to improvements in sleep.

Addressing the Critical Gap: Ensuring Urgent Access to Palliative Care Services with Essential Medications in Nepal

Palliative care is essential for life-threatening illnesses. However, Nepal still faces significant challenges in accessing primary palliative care services, including required medications, particularly in rural areas. This commentary highlights the need for policies and guidelines to ensure equitable access to palliative care with medicines. While limited studies in Nepal confirmed the demand, challenges persist in rural areas with deficient access to quality healthcare. This article discusses the existing efforts and noteworthy initiatives implemented by healthcare institutions. However, these efforts are currently limited in scale. We recommend including essential palliative care medicines in government healthcare policies, establishing training programs for healthcare professionals, and developing comprehensive policies with detailed field research work to meet the growing demand. Addressing these issues will significantly improve the quality of life for palliative care patients in Nepal.

Efficacy of Continuous Intravenous Fentanyl for Oral Mucosal Pain in Stevens-Johnson Syndrome: A Case Report

The management of oral mucosal pain in Stevens-Johnson syndrome (SJS), known for its severe mucocutaneous reactions, is a significant challenge due to the paucity of effective treatments reported in the literature. This case report aims to help fill this gap by describing the effective use of continuous intravenous fentanyl for the relief of severe oral mucosal pain in a patient with SJS. A patient with postoperative recurrence of cervical cancer developed SJS following chemotherapy. She had severe oral mucosal pain that was not relieved by 12.5 mcg/hour fentanyl transdermal patch, a regular medication. This pain was rated 10/10 on the Numerical Pain Rating Scale (NRS), and the patient had dysphagia and difficulty speaking. On admission, intravenous methylprednisolone (1000 mg/day), oral lip treatment with dexamethasone ointment, and oral rinses with azulene-lidocaine mixture were started. Analgesic treatment consisted of a 12.5 mcg/hour fentanyl transdermal patch of the regular medication and 1000 mg/dose of intravenous acetaminophen twice daily. Due to the inadequate efficacy of the transdermal patch, fentanyl was switched from the transdermal patch to a continuous intravenous fentanyl infusion at 20 mcg/hour on day three of admission. This adjustment significantly reduced pain intensity, which decreased to NRS 5/10 on day six of admission, and the patient was able to drink water and speak. Pain relief preceded clinical improvement of stomatitis. Grade 1 somnolence occurred after the start of intravenous fentanyl, but improved with follow-up. There were no other adverse effects such as respiratory depression. This case highlights the potential of intravenous fentanyl in the treatment of oral mucosal pain associated with SJS, although further studies are needed to confirm these findings and to develop comprehensive pain management protocols.

Morphine (10, 20 mg) in a Postoperative Dressing Used with Patients After Surgical Debridement of Burn Wounds: A Prospective, Double-Blinded, Randomized Controlled Trial

Objective: This is the first clinical trial to evaluate the analgesic effect of 10 and 20 mg of morphine used in a postoperative dressing with patients after surgical debridement of burn wounds. Approach: In this randomized controlled trial, 20 adult patients with third-degree flame burns, who had undergone surgical debridement under general anesthesia, were randomly assigned to either group A, whose members were treated with a burn dressing that contained 10 mg of morphine, or group B, whose members were treated with a burn dressing that contained 20 mg of morphine; the dressing was also soaked with octenidine and phenoxyethanol in the case of both groups. The plasma morphine concentrations were measured 1, 2, 3, and 6 h after surgery, while the level of pain intensity was determined on the Numeric Pain Rating Scale (NRS), and the occurrence of side effects was observed. Results: The serum morphine concentration levels were very low, but statistically different between the two groups at all time points. The NRS value was similar in both groups at all time points (p > 0.05). Despite this, in group B, the NRS value was 0 in all patients in postoperative hours 1, 2, and 3. No adverse effect of morphine sulfate was observed in any patient. Innovation: This project is the first clinical study to have demonstrated that morphine administered in dressings in concentrations of 0.02-0.08 mg/mL significantly reduces the occurrence of pain. Conclusion: The use of morphine in dressings after surgical treatment of burn wounds is very effective when it comes to pain management and is safe for the patient.

Comparison of analgesic efficacy of tramadol, morphine and methadone in cats undergoing ovariohysterectomy

OBJECTIVES

The aim of this study was to compare the analgesic efficacy and the effect on physiological variables and behavior of the use of tramadol, methadone and morphine as preoperative analgesia in healthy cats undergoing elective ovariohysterectomy.

METHODS

Cats undergoing ovariohysterectomy were randomly assigned to receive one of the following premedication treatments intramuscularly: methadone (0.2 mg/kg; n = 10); morphine (0.2 mg/kg; n = 10); or tramadol (3 mg/kg; n = 10). Induction of anesthesia was done with propofol, and maintenance of anesthesia was done with isoflurane. Intraoperative heart rate, arterial blood pressure, respiratory rate, end-tidal isoflurane concentration and frequency of rescue analgesia (fentanyl 2.5 µg/kg) were compared between groups. Postoperative analgesia was assessed using the UNESP-Botucatu Multidimensional Composite Pain Scale, and perioperative serum glucose, cortisol concentrations and postoperative rescue analgesia were evaluated.

RESULTS

Intraoperative rescue analgesia was required in 76.5% of cats at some time during surgery, and 27% of cats required postoperative rescue analgesia up to 6 h after extubation. There were no significant differences between groups with respect to intraoperative and postoperative rescue analgesia, pain scale scores and end-tidal isoflurane concentrations. In the immediate postoperative period, after extubation, most of the patients presented with hypothermia; however, 1-6 h postoperatively, hyperthermia was observed in most of the patients, and was most common in the tramadol group.

CONCLUSIONS AND CLINICAL RELEVANCE

Under the conditions of this study, methadone, morphine and tramadol produced satisfactory postoperative analgesia in most of the cats undergoing ovariohysterectomy, and the effects lasted up to 6 h postoperatively. Intraoperative analgesia was not sufficient in most cases. Significant cardiovascular or respiratory effects contraindicating the use of these drugs were not found. Postanesthetic hyperthermia occurred with all opioids studied and was more frequent in the tramadol group.

The impact of opioid administration on the incidence of postanaesthetic colic in horses

Effective management of postoperative pain is essential to ensure patient welfare, reduce morbidity and optimize recovery. Opioids are effective in managing moderate to severe pain in horses but concerns over their adverse effects on gastrointestinal (GI) motility and associated increased colic risk limit their widespread use. Studies investigating the impact of systemic opioids on both GI motility and colic incidence in horses have yielded inconclusive outcomes. Therefore, this retrospective study aims to assess the influence of systemic administration of butorphanol, morphine, and methadone on post-anaesthetic colic (PAC) incidence. Horses undergoing general anaesthesia for non-gastrointestinal procedures that were hospitalized for at least 72 h post-anaesthesia were included in this study. Anaesthetised horses were stratified by procedure type into horses undergoing diagnostic imaging without surgical intervention, emergency or elective surgery. In addition, patients were grouped by opioid treatment regime into horses receiving no opioids, intraanaesthetic, short- (<24 h) or long-term (>24 h) postoperative opioids. Administered opioids encompassed butorphanol, morphine and methadone. The number of horses showing signs of colic in the 72 h after anaesthesia was assessed for each group. A total of 782 horses were included, comprising 659 undergoing surgical procedures and 123 undergoing diagnostic imaging. The overall PAC incidence was 15.1%. Notably, horses undergoing diagnostic imaging without surgery had a significantly lower PAC rate of 6.5% compared to those undergoing surgery (16.7%, p = 0.0146). Emergency surgeries had a significantly lower PAC rate of 5.8% compared to elective procedures (18%, p = 0.0113). Of the 782 horses, 740 received intraoperative opioids and 204 postoperative opioids, 102 of which long-term (≥24 h). Neither intraoperative (p = 0.4243) nor short-term postoperative opioids (p = 0.5744) increased PAC rates. Notably, only the long-term (≥24 h) administration of morphine significantly increased PAC incidence to 34% (p = 0.0038). In contrast, long-term butorphanol (5.3% PAC, p = 0.8482) and methadone (18.4% PAC, p = 0.6161) did not affect PAC rates. In summary, extended morphine administration was the only opioid treatment associated with a significantly increased risk of PAC.

Beyond Traditional Pain Relief: A Review of Alternative Analgesics in Myocardial Infarction Patient Management

While morphine is the recommended first-line treatment for pain management in patients with acute coronary syndrome, recent studies have raised concerns about its association with adverse outcomes. Morphine has been found to cause delayed antiplatelet effects, decreased ticagrelor absorption, increased platelet reactivity, and compromised efficacy of dual antiplatelet therapy (DAPT). Alternative analgesics, such as lidocaine, fentanyl, and acetaminophen, have begun to emerge as viable alternatives, each with unique mechanisms and potential benefits. Lidocaine is demonstrated to have superior effects in reducing microvascular obstruction and fewer adverse events compared to fentanyl, despite being less effective in pain reduction. Fentanyl, which shows rapid onset and powerful analgesic properties, may interfere with ticagrelor absorption, potentially affecting platelet inhibition. Acetaminophen, a centrally acting analgesic, emerges as a safer alternative with comparable pain relief efficacy and minimal side effects. The results of multiple clinical trials emphasize the significance of customizing pain management approaches to match individual patient profiles and achieving the optimal balance between pain relief and potential adverse outcomes.

The Effect of Epidural Analgesia on Quality of Recovery (QoR) after Open Radical Nephrectomy: Randomized, Prospective, and Controlled Trial

No studies are currently evaluating the quality of recovery (QoR) after open radical nephrectomy (ORN) and epidural morphine analgesia. This was a randomized, prospective, and controlled study that explored the QoR on the first postoperative day after ORN. Eighty subjects were randomized into two groups. The first group received general anesthesia combined with epidural anesthesia and postoperative epidural analgesia with morphine and ropivacaine. The second group received general anesthesia and continuous postoperative intravenous analgesia with tramadol. Both groups received multimodal analgesia with metamizole. The primary outcome measure was the total QoR-40 score. The secondary outcome measures were QoR-15, QoR-VAS, and the visual analog scale (VAS) for pain, anxiety, and nausea. The median difference in the QoR-40 score after 24 postoperative hours between the two groups of patients was 10 (95% CI: 15 to 5), p < 0.0001. The median score and IQR of QoR-40 during the first 24 postoperative hours in the epidural group was 180 (9.5), and in the control group, it was 170 (13). The general independence test for secondary outcomes between groups was significant (p < 0.01). QoR-VAS was correlated with QoR-40 (r = 0.63, p ≤ 0.001) and with QoR-15 (r = 0.54, p ≤ 0.001). The total QoR-40 and QoR-15 alpha coefficients with a 95% CI were 0.88 (0.85-0.92) and 0.73 (0.64-0.81), respectively. There was a significant difference in the QoR between the epidural and the control groups after ORN. The QoR-40 and QoR-15 showed good convergent validity and reliability.

Neural Network Connectivity Following Opioid Dependence is Altered by a Common Genetic Variant in the µ-Opioid Receptor, OPRM1 A118G

Opioid use disorder is a chronic, relapsing disease associated with persistent changes in brain plasticity. A common single nucleotide polymorphism (SNP) in the µ-opioid receptor gene, OPRM1 A118G, is associated with altered vulnerability to opioid addiction. Reconfiguration of neuronal connectivity may explain dependence risk in individuals with this SNP. Mice with the equivalent Oprm1 variant, A112G, demonstrate sex-specific alterations in the rewarding properties of morphine and heroin. To determine whether this SNP influences network-level changes in neuronal activity, we compared FOS expression in male and female mice that were opioid-naive or opioid-dependent. Network analyses identified significant differences between the AA and GG Oprm1 genotypes. Based on several graph theory metrics, including small-world analysis and degree centrality, we show that GG females in the opioid-dependent state exhibit distinct patterns of connectivity compared to other groups of the same genotype. Using a network control theory approach, we identified key cortical brain regions that drive the transition between opioid-naive and opioid-dependent brain states; however, these regions are less influential in GG females leading to sixfold higher average minimum energy needed to transition from the acute to the dependent state. In addition, we found that the opioid-dependent brain state is significantly less stable in GG females compared to other groups. Collectively, our findings demonstrate sex- and genotype-specific modifications in local, mesoscale, and global properties of functional brain networks following opioid exposure and provide a framework for identifying genotype differences in specific brain regions that play a role in opioid dependence.