Efficacy of intravenous dexmedetomidine-lignocaine infusion compared to morphine for intraoperative haemodynamic stability in modified radical mastectomy: A randomised controlled trial

Background and Aims

In recent times, non-opioid analgesic-based anaesthesia has been gaining popularity as it can achieve the goals of hypnosis, amnesia, and haemodynamic stability while avoiding opioid side effects. Our study compares the efficacy of opioid-free anaesthesia and opioid-based general anaesthesia regarding intraoperative haemodynamic stability, anaesthetic requirements, awareness, and recovery profile.

Methods

After receiving ethical approval and registering the trial, we conducted this randomised, single-blinded study on American Society of Anesthesiologists (ASA) physical status I and II patients who were aged 18-65 and were scheduled for modified radical mastectomy under general anaesthesia. Patients were randomised into two groups of 60 each. Group DL received IV dexmedetomidine 1 μg/kg loading over 10 min, 10 min before induction and 0.5 μg/kg/h infusion after that along with IV lignocaine 1.5 mg/kg at bolus followed by 1.5 mg/kg/h infusion. Group MN received IV morphine 0.15 mg/kg. Standard monitoring and general anaesthesia protocol were followed. Intraoperative haemodynamics, anaesthetic requirement, extubation time, and recovery profile were monitored. Data were analysed using Stata version 14 software, and statistical tests (Chi-squared test for qualitative variables, unpaired t-test and Mann-Whitney U test for quantitative variables) were performed.

Results

Both groups had comparable haemodynamic stability (P > 0.05). Group DL had a significantly lower propofol requirement for induction and maintenance (P < 0.001). Ramsay sedation score (P = 0.002) and extubation time (P = 0.029) were significantly higher in Group MN. The recovery profile was favourable in Group DL, with there being lower postoperative complications.

Conclusion

Dexmedetomidine and lignocaine IV infusion demonstrated stable intraoperative haemodynamic stability, lower anaesthetic requirement, and better recovery profile than morphine without significant complications.

The Role of circTmeff-1 in Morphine Addiction Memory of Mice

In addition to the essential pharmacological effects of opioids, situational cues associated with drug addiction memory are key triggers for drug seeking. CircRNAs, an emerging hotspot regulator in crown genetics, play an important role in central nervous system-related diseases. However, the internal mediating mechanism of circRNAs in the field of drug reward and addiction memory remains unknown. Here, we trained mice on a conditional place preference (CPP) model and collected nucleus accumbens (NAc) tissues from day 1 (T0) and day 8 (T1) for high-throughput RNA sequencing. QRT-PCR analysis revealed that circTmeff-1 was highly expressed in the NAc core but not in the NAc shell, suggesting that it plays a role in addiction memory formation. Meanwhile, the down-regulation of circTmeff-1 by adeno-associated viruses in the NAc core or shell could inhibit the morphine CPP scores. Subsequently, the GO and KEGG analyses indicated that circTmeff-1 might regulate the addiction memory via the MAPK and AMPK pathways. These findings suggest that circTmeff-1 in NAc plays a crucial role in morphine-dependent memory formation.

[Retracted] Morphine‑induced delayed pre‑conditioning against anoxia/reoxygenation injury in pulmonary artery endothelial cells: The role of mitochondrial KATP channels

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that several of the flow cytometric plots featured in Fig. 2A on p. 1050 contained repeating patterns of dots, both vertically and horizontally, in addition to a variety of other apparent anomalies. The authors were asked to provide an explanation to account for the apparent anomalies in this figure, but they did not respond to the request posed by the Editorial Office. Therefore, the Editor of Molecular Medicine Reports has decided that this paper should be retracted from the journal on account of a lack of confidence in the presented data. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 13: 1047‑1053, 2016; DOI: 10.3892/mmr.2015.4629].

Novel single nucleotide polymorphism biomarkers to predict opioid effects for cancer pain

There have been few studies on predictive biomarkers that may be useful to select the most suitable opioids to optimize therapeutic efficacy in individual patients with cancer pain. We recently investigated the efficacy of morphine and oxycodone using single nucleotide polymorphisms (SNPs) of the catechol-O-methyltransferase (COMT) rs4680 gene as a biomarker (RELIEF study). To explore additional biomarkers that may enable the selection of an appropriate opioid for individual patients with cancer pain, three SNPs were examined: C-C motif chemokine ligand 11 (CCL11; rs17809012), histamine N-methyltransferase (HNMT; rs1050891) and transient receptor potential V1 (TRPV1; rs222749), which were screened from 74 pain-related SNPs. These SNPs, which were identified as being significantly associated with the analgesic effect of morphine, were then used to genotype the 135 patients in the RELIEF study who had been randomized into a morphine group (n=69) or an oxycodone group (n=66). The present study then assessed whether the SNPs could also be used as selective biomarkers to predict which opioid(s) might be the most suitable to provide pain relief for patients with cancer. Oxycodone tended to provide superior analgesic effects over morphine in patients carrying the genotype AA for the CCL11 rs17809012 SNP (P=0.012 for interaction), suggesting that it could serve as a potential biomarker for personalized analgesic therapy for patients suffering with cancer pain.

Neonatal Abstinence Syndrome: A Review of Treatment in the Neonatal Intensive Care Unit

Background

Neonatal abstinence syndrome (NAS) is a collection of symptoms that neonates may experience following antenatal exposure to substances that induce withdrawal. Optimal management remains unknown, and there is variation in management and outcomes.

Objectives

To describe the management, length of hospitalization, and adverse events in near-term and full-term neonates with NAS for whom treatment (pharmacotherapy and/or supportive care) was initiated in the neonatal intensive care unit (NICU).

Methods

A chart review was conducted of neonates admitted to the NICU of Surrey Memorial Hospital, Surrey, British Columbia, who received treatment for NAS between September 1, 2016, and September 1, 2021.

Results

A total of 48 neonates met the inclusion criteria. Opioids represented the most frequent type of antenatal exposure. Polysubstance exposures occurred in 45 (94%) of the neonates. Morphine was given to 29 (60%) of the neonates, and phenobarbital to 6 (13%); 5 of these neonates received both medications. The average duration of morphine treatment was 14 days, and the average length of hospitalization (all patients) was 16 days. All of the neonates experienced adverse events; in particular, 9 (30%) of the 30 who received pharmacotherapy were too sedated to feed, compared with 0% of the 18 with no pharmacotherapy.

Conclusions

The common finding of polysubstance antenatal exposure, involving predominantly opioids, was associated with scheduled morphine pharmacotherapy for the majority of patients, prolonged hospitalization, and frequent adverse events. Pharmacotherapy for NAS was associated with levels of sedation that interfered with feeding in neonates.

Comparative Study Between Intravenous Patient-Controlled Analgesia Morphine and Computerized Ambulatory Delivery Device Epidural Morphine for Post Operative Analgesia for Nuss Procedure in Pectus Excavatum: A Retrospective Analysis

BACKGROUND

Pectus deformities are commonly seen in chest wall deformities among the pediatric age group. Pectus deformities occur due to defective growth of the sternum and its surrounding cartilage. The Nuss procedure is the technique of choice for correcting the deformity surgically which includes placing a convex bar under the sternum without resection or injury to costal cartilages. Adequate pain control is utmost to improve wound healing, patient satisfaction, short hospital stays, and decrease the financial burden on attendants. Therefore, it is necessary to investigate which analgesic method is more advantageous for the Nuss procedure.

OBJECTIVE

To compare the analgesic effects of intravenous patient-controlled analgesia (IVPCA) morphine versus computerized ambulatory delivery device (CADD) epidural morphine on acute post-operative pain management in Nuss procedures.

METHODS

A retrospective study was done at Rajiv Gandhi Cancer and Research Hospital, New Delhi from 2015 to 2020 to assess the efficacy and safety between IVPCA morphine and CADD epidural for post-operative analgesia following pectus excavatum repair. A total of 34 cases of Nuss procedures were taken with 17 cases in each group. Group 1 (intravenous PCA morphine) was given 39 ml normal saline + 6 ml morphine (total 45 ml, 2 mg/ml morphine), set at demand dose 0.5 ml, i.e. 1 mg, lockout interval 7 minutes, doses per hour was six and Group 2 (CADD epidural morphine) was given 42 ml normal saline + 3 ml morphine (1 mg/ml morphine) with continuous infusion at the rate of 0.5 ml/hr. Demand dose 0, lockout interval nil. Visual analog pain scores using a scale of 0-10 and Ramsay Sedation Score (RSS) scores were obtained on arrival at the post-anesthesia care unit, at 12, 24, 48, and 72 hours throughout the subsequent hospital stay.

RESULTS

This study yielded positive information about our experience with the pectus post-operative pain management. The mean visual analog scale (VAS) score was lower in Group 1 compared to Group 2 but significantly different at 12 and 72 hours only. The mean RSS score was comparable between groups. The mean hospital stay (days) and requirement of rescue analgesia doses were 3.47±0.51 and 0.12±0.33 in Group 1 and 4.76±0.44, 0.59±1.12 in Group 2.

CONCLUSION

 Both IVPCA morphine and CADD morphine were effective in controlling post-surgical pain in the Nuss procedure, but IVPCA morphine was better as compared to CADD morphine in this regard because it was noninvasive, safe, and cost-effective with non-significant complications.

Ultrasound-guided anterior suprascapular nerve block versus interscalene brachial plexus block for arthroscopic shoulder surgery: A randomised controlled study

Background and Aims

The interscalene brachial plexus block (ISB) affects the phrenic nerve, resulting in hemi-diaphragmatic paresis (HDP) and, possibly, respiratory distress. Suprascapular nerve block via an anterior approach (SSB-A) is performed more distally at the level of the trunk of the brachial plexus and, thus, may spare the phrenic nerve. This study compares the analgesic efficacy and decline of hemi-diaphragmatic excursion (HDE) following ultrasound (US)-guided SSB-A versus ISB for arthroscopic shoulder surgery.

Methods

This study was conducted on 60 adult participants undergoing arthroscopic shoulder surgery under general anaesthesia. Both US-guided SSB-A (n = 30) and ISB (n = 30) were performed with a combination of 10 ml bupivacaine (0.5%) and 4 mg dexamethasone. The primary objective was to compare the duration of analgesia (time to first rescue analgesia), and secondary objectives were to compare 24-h postoperative numerical rating scale (NRS) scores, 24-h morphine consumption and post block change in HDE, and pulmonary function tests (PFTs) between the two groups. For analysing intergroup differences of NRS, HDE and PFT; Pearson's Chi-squared test or Fisher's exact test, unpaired t test, and Mann-Whitney U test were used. For intragroup differences, paired t test was used. A P value <0.05 was considered significant.

Results

The duration of analgesia (mean ± Standard Deviation) was similar in two groups (SSB-A = 1,345 ± 182 min, ISB = 1,375 ± 156 min; P = 0.8). The reduction in HDE was significantly greater in the ISB group (44%) than in the SSB-A group (10%). Pulmonary function was better preserved in the SSB-A group.

Conclusion

Compared to ISB, SSB-A has a similar analgesic efficacy for arthroscopic shoulder surgeries, but it is superior in preserving diaphragmatic function and pulmonary function.

Etoricoxib Can Reduce Post-Operative Morphine Consumption and Pain Score in Patients Undergoing Lumbar Laminectomy Compare to Acetaminophen: A Randomized Trial

STUDY DESIGN

Randomized controlled trial.

OBJECTIVES

This prospective trial aimed to compare the effectiveness of etoricoxib and acetaminophen in terms of post-operative morphine consumption and pain score in patients undergoing lumbar laminectomy.

METHODS

Forty lumbar-laminectomy patients aged between 18 and 50 years were enrolled, randomized, and allocated into either the etoricoxib group or the acetaminophen group. The measures assessed were the amount of morphine consumed and pain visual analog score (VAS) at 12, 24, and 48 hours after surgery. Adverse events were recorded.

RESULTS

Patients in the etoricoxib group had statistically significantly lower morphine consumption than those in the acetaminophen group at 12 hours (P-value = .006), 24 hours (P-value = .006) and 48 hours (P-value = .011). Patients in the etoricoxib group had lower VAS scores than those in the acetaminophen group at 0, 12, 24, 48 hours, the difference being statistically significant at 48 hours (P < .001).

CONCLUSIONS

Compared to acetaminophen, etoricoxib can significantly reduce post-operative morphine consumption and improve the pain score at 12, 24, and 48 hours.

Low Current Intensity Plus an Ineffective Dose of Morphine Affect Conditioning Place Preference Through Different Pathways in the Lateral Habenula

Background

The involvement of lateral habenula and the ineffective dose of morphine on reward-related learning and memory is less well-known. This study looked into the effects of electrical stimulation, GABAB receptor blockade, and a combination of both with morphine on conditioned place preference.

Materials and Methods

In this experiment, male rats were anesthetized with ketamine/xylazine (six rats in each group). A 5-day biased conditioned place preference paradigm was used for the behavioral test. The effects of electrical stimulation and phaclofen plus a low dose of morphine on the acquisition and expression phases were examined during conditioning sessions and before the test phase, respectively.

Results

The conditioning scores were reduced by antagonist injection during the acquisition phase. Interestingly, different intensities exhibited opposite effects on the acquisition phase. Conditioned place preference scores during the acquisition phase were significantly induced by 25 μA electrical stimulation, while conditioning scores were suppressed by electrical stimulation at 150 μA. Phaclofen (2 μg/rat) combined with high intensity induced aversion during the acquisition phase, while inhibiting expression. In contrast, high intensity with phaclofen (1 μg/rat) inhibited only the acquisition session. However, low intensity during the acquisition phase had an additive effect that was prevented by pretreatment with phaclofen (2 μg/rat), but this response was modified by the antagonist's low dose.

Conclusions

A behavioral technique called conditioned place preference is frequently used to evaluate learning that is related to rewards. Therefore, lateral habenula electrical stimulation and phaclofen plus morphine could affect place preference through the involvement of the reward system.

Effects of the Co-Administration of Morphine and Lipopolysaccharide on Toll-Like Receptor-4/Nuclear Factor Kappa β Signaling Pathway of MDA-MB-231 Breast Cancer Cells

Background

The Toll-like receptor 4 (TLR4) gene promotes migration in adenocarcinoma cells. Morphine is an agonist for TLR4 that has a dual role in cancer development. The promoter or inhibitor role of morphine in cancer progression remains controversial. This study aims to evaluate the effects of morphine on the TLR4, myeloid differentiation primary response protein 88-dependent (MyD88), and nuclear factor-kappa B (NF-κB) expressions in the human MDA-MB-231 breast cancer cell line.

Materials and Methods

The cells were examined after 24 hours of incubation with morphine using the Boyden chamber system. TLR4, MyD88, and NF-κB mRNA expressions were assessed using quantitative real-time polymerase chain reaction (RT-PCR). The concentration of interleukin-2 beta was also measured using the ELISA assay.

Results

According to the findings, three doses of morphine (0.25, 1.25, and 0.025 μM) increased the expression of the TLR4 and NF-κB genes, whereas no significant change was observed in the mRNA expression of MyD88. Furthermore, treatment with morphine and lipopolysaccharide (LPS) significantly decreased the expression of TLR4, MyD88, and NF-κB. However, no significant change was observed in interleukin 2 beta concentration.

Conclusions

These findings confirmed the excitatory effects of morphine on TRL4 expression and the MYD88 signaling pathway in vitro.

Opioid Analgesics after Bariatric Surgery: A Scoping Review to Evaluate Physiological Risk Factors for Opioid-Related Harm

The persisting use of opioids following bariatric surgery has emerged as a prevalent complication, heightening the probability of opioid-related harm (ORM), such as opioid-related fatalities and prescription opioid use disorder (OUD). A comprehensive review of PubMed literature from 1990 to 2023 was conducted to pinpoint physiological influences on postoperative ORM. As a result, we found that patients undertaking bariatric operations often exhibit an inherently higher risk for substance use disorders, likely attributable to genetic predisposition and related neurobiological changes that engender obesity and addiction-like tendencies. Furthermore, chronic pain is a common post-bariatric surgery complaint, and the surgical type impacts opioid needs, with increased long-term opioid use after surgeries. Additionally, the subjective nature of pain perception in patients with obesity can distort pain reporting and the corresponding opioid prescription both before and after surgery. Furthermore, the postoperative alterations to the gastrointestinal structure can affect the microbiome and opioid absorption rates, resulting in fluctuating systemic exposure to orally ingested opioids. The prospect of ORM development post-bariatric surgery appears amplified due to a preexisting susceptibility to addictive habits, surgically induced pain, modified gut-brain interaction and pain management and the changed pharmacokinetics post-surgery. Further research is warranted to clarify these potential risk variables for ORM, specifically OUD, in the bariatric population.

Activation of the mu-delta opioid receptor heteromers blocks morphine rewarding effects

BACKGROUND

Evidence has accumulated demonstrating the existence of opioid receptor heteromers and recent data suggest that targeting these heteromers could reduce opioid side effects while retaining therapeutic effects. Indeed, CYM51010 characterised as a MOR (mu opioid receptor)/DOR (delta opioid receptor) heteromers preferring agonist promoted antinociception comparable to morphine but with less tolerance. In the perspective of developing these new classes of pharmacological agents, data on their putative side effects are mandatory.

METHODS

Therefore, in this study, we investigated the effects of CYM51010 in different models related to drug addiction in mice including behavioural sensitization, conditioned place preference and withdrawal.

RESULTS

We found that, like morphine, CYM51010 promoted acute locomotor activity as well as psychomotor sensitization and rewarding effect. However, it induced less physical dependence than morphine. We also investigated the ability of CYM51010 to modulate some morphine-induced behaviour. Whereas CYM51010 was unable to block morphine-induced physical dependence, it blocked reinstatement of an extinguished morphine induced-conditioned place preference.

CONCLUSIONS

Altogether, our results reveal that targeting MOR-DOR heteromers could represent a promising strategy to block morphine reward.

A Novel UHPLC-MS/MS Method for the Quantification of Seven Opioids in Different Human Tissues

BACKGROUND

Opioids are considered the cornerstone of pain management: they show good efficacy as a first-line therapy for moderate to severe cancer pain. Since pharmacokinetic/pharmacodynamic information about the tissue-specific effect and toxicity of opioids is still scarce, their quantification in post-mortem autoptic specimens could give interesting insights.

METHODS

We describe an ultra-high-performance liquid chromatography coupled with tandem mass spectrometry method for the simultaneous quantification of methadone, morphine, oxycodone, hydrocodone, oxymorphone, hydromorphone and fentanyl in several tissues: liver, brain, kidney, abdominal adipose tissue, lung and blood plasma. The presented method has been applied on 28 autoptic samples from different organs obtained from four deceased PLWH who used opioids for palliative care during terminal disease.

RESULTS

Sample preparation was based on tissue weighing, disruption, sonication with drug extraction medium and a protein precipitation protocol. The extracts were then dried, reconstituted and injected onto the LX50 QSight 220 (Perkin Elmer, Milan, Italy) system. Separation was obtained by a 7 min gradient run at 40 °C with a Kinetex Biphenyl 2.6 µm, 2.1 × 100 mm. Concerning the analyzed samples, higher opioids concentrations were observed in tissues than in plasma. Particularly, O-MOR and O-COD showed higher concentrations in kidney and liver than other tissues (>15-20 times greater) and blood plasma (>100 times greater).

CONCLUSIONS

Results in terms of linearity, accuracy, precision, recovery and matrix effect fitted the recommendations of FDA and EMA guidelines, and the sensitivity was high enough to allow successful application on human autoptic specimens from an ethically approved clinical study, confirming its eligibility for post-mortem pharmacological/toxicological studies.

Morphine pharmacokinetics and opioid transporter expression at the blood-retina barrier of male and female mice

Opioids are effective analgesics for treating moderate to severe pain, however, their use must be weighed against their dangerous side effects. Investigations into opioid pharmacokinetics provide crucial information regarding both on- and off-target drug effects. Our recent work showed that morphine deposits and accumulates in the mouse retina at higher concentrations than in the brain upon chronic systemic exposure. We also found reduced retinal expression of P-glycoprotein (P-gp), a major opioid extruder at the blood-brain barrier (BBB). Here, we systematically interrogated the expression of three putative opioid transporters at the blood-retina barrier (BRB): P-gp, breast cancer resistance protein (Bcrp) and multidrug resistance protein 2 (Mrp2). Using immunohistochemistry, we found robust expression of P-gp and Bcrp, but not Mrp2, at the inner BRB of the mouse retina. Previous studies have suggested that P-gp expression may be regulated by sex hormones. However, upon acute morphine treatment we found no sex differences in morphine deposition levels in the retina or brain, nor on transporter expression in the retinas of males and females with a high or low estrogen:progesterone ratio. Importantly, we found that P-gp, but not Bcrp, expression significantly correlated with morphine concentration in the retina, suggesting P-gp is the predominant opioid transporter at the BRB. In addition, fluorescence extravasation studies revealed that chronic morphine treatment did not alter the permeability of either the BBB or BRB. Together, these data suggest that reduced P-gp expression mediates retinal morphine accumulation upon systemic delivery, and in turn, potential effects on circadian photoentrainment.

Peripheralization Strategies Applied to Morphinans and Implications for Improved Treatment of Pain

Opioids are considered the most effective analgesics for the treatment of moderate to severe acute and chronic pain. However, the inadequate benefit/risk ratio of currently available opioids, together with the current 'opioid crisis', warrant consideration on new opioid analgesic discovery strategies. Targeting peripheral opioid receptors as effective means of treating pain and avoiding the centrally mediated side effects represents a research area of substantial and continuous attention. Among clinically used analgesics, opioids from the class of morphinans (i.e., morphine and structurally related analogues) are of utmost clinical importance as analgesic drugs activating the mu-opioid receptor. In this review, we focus on peripheralization strategies applied to N-methylmorphinans to limit their ability to cross the blood-brain barrier, thus minimizing central exposure and the associated undesired side effects. Chemical modifications to the morphinan scaffold to increase hydrophilicity of known and new opioids, and nanocarrier-based approaches to selectively deliver opioids, such as morphine, to the peripheral tissue are discussed. The preclinical and clinical research activities have allowed for the characterization of a variety of compounds that show low central nervous system penetration, and therefore an improved side effect profile, yet maintaining the desired opioid-related antinociceptive activity. Such peripheral opioid analgesics may represent alternatives to presently available drugs for an efficient and safer pain therapy.

Differential Effects of Cocaine and Morphine on the Diurnal Regulation of the Mouse Nucleus Accumbens Proteome

Substance use disorders are associated with disruptions in sleep and circadian rhythms that persist during abstinence and may contribute to relapse risk. Repeated use of substances such as psychostimulants and opioids may lead to significant alterations in molecular rhythms in the nucleus accumbens (NAc), a brain region central to reward and motivation. Previous studies have identified rhythm alterations in the transcriptome of the NAc and other brain regions following the administration of psychostimulants or opioids. However, little is known about the impact of substance use on the diurnal rhythms of the proteome in the NAc. We used liquid chromatography coupled to tandem mass spectrometry-based quantitative proteomics, along with a data-independent acquisition analysis pipeline, to investigate the effects of cocaine or morphine administration on diurnal rhythms of proteome in the mouse NAc. Overall, our data reveal cocaine and morphine differentially alter diurnal rhythms of the proteome in the NAc, with largely independent differentially expressed proteins dependent on time-of-day. Pathways enriched from cocaine altered protein rhythms were primarily associated with glucocorticoid signaling and metabolism, whereas morphine was associated with neuroinflammation. Collectively, these findings are the first to characterize the diurnal regulation of the NAc proteome and demonstrate a novel relationship between the phase-dependent regulation of protein expression and the differential effects of cocaine and morphine on the NAc proteome. The proteomics data in this study are available via ProteomeXchange with identifier PXD042043.

Predicting favorable response to intravenous morphine in pediatric critically ill cardiac patients

INTRODUCTION

Analgesia and sedation are integral to the care of critically ill children. However, the choice and dose of the analgesic or sedative drug is often empiric, and models predicting favorable responses are lacking. We aimed to compute models to predict a patient's response to intravenous morphine.

METHODS

We retrospectively analyzed data from consecutive patients admitted to the Cardiac Intensive Care Unit (January 2011- January 2020) who received at least one intravenous bolus of morphine. The primary outcome was a decrease in the State Behavioral Scale (SBS) ≥1 point; the secondary outcome was a decrease in the heart rate Z-score (zHR) at 30 minutes. Effective doses were modeled using logistic regression, Lasso regression, and random forest modeling.

RESULTS

A total of 117,495 administrations of intravenous morphine among 8,140 patients (median age 0.6 years [interquartile range [IQR] 0.19, 3.3]) were included. The median morphine dose was 0.051 mg/kg (IQR 0.048, 0.099) and the median 30-day cumulative dose was 2.2 mg/kg (IQR 0.4, 15.3). SBS decreased following 30% of doses, did not change following 45%, and increased following 25%. The zHR significantly decreased after morphine administration (median delta-zHR -0.34 (IQR-1.03, 0.00), P<0.001). A concomitant infusion of propofol, higher prior-30-day cumulative dose, being invasively ventilated and/or on vasopressors were associated with favorable response to morphine. Higher morphine dose, higher zHR pre-morphine, an additional analgosedation bolus ±30 minutes around the index bolus, a concomitant ketamine or dexmedetomidine infusion, and showing signs of withdrawal syndrome were associated with unfavorable response. Logistic regression (area under the receiver operating characteristic [ROC] curve [AUC] 0.900) and machine learning models (AUC 0.906) performed comparably, with a sensitivity of 95%, specificity of 71%, and negative predictive value of 97%.

CONCLUSIONS

Statistical models identify 95% of effective intravenous morphine doses in pediatric critically ill cardiac patients, while incorrectly suggesting an effective dose in 29% of cases. This work represents an important step towards computer-aided, personalized clinical decision support tool for sedation and analgesia in ICU patients.

Detection of Three Opioids (Morphine, Codeine and Methadone) and Their Metabolites (6-Monoacetylmorphine and 2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine) in Larvae of Lucilia sericata Species by UHPLC-TF-MS and Validation

Insects on corpses could be a useful tool for the detection of exogenous substances such as drugs of abuse. The identification of exogenous substances in carrion insects is critical for proper estimation of the postmortem interval. It also provides information about the deceased person that may prove useful for forensic purposes. High-performance liquid chromatography coupled with Fourier transform mass spectrometry is a highly sensitive analytical technique that can identify substances even at very low concentrations, such as in the case of searching for exogenous substances in larvae. In this paper, a method is proposed for the identification of morphine, codeine, methadone, 6-monoacetylmorphine (6-MAM) and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) in the larvae of Lucilia sericata, a common carrion fly widely distributed in temperate areas of the world. The larvae, which were reared on a pig meat substrate, were killed once they reached their third stage by immersion in hot water at 80 °C and aliquoted into 400 mg samples. The samples were fortified with 5 ng of morphine, methadone and codeine. After solid-phase extraction, the samples were processed with a liquid chromatograph coupled to a Fourier transform mass spectrometer. This qualitative method has been validated and tested on larvae from a real case. The results lead to the correct identification of morphine, codeine, methadone and their metabolites. This method could prove useful in cases where toxicological analysis must be conducted on highly decomposed human remains, where biological matrices are very limited. Furthermore, it could help the forensic pathologist to better estimate the time of death, as the growth cycle of carrion insects can undergo changes if exogenous substances are taken.

Cannabis-based medicines and medical cannabis for adults with cancer pain

BACKGROUND

Pain is a common symptom in people with cancer; 30% to 50% of people with cancer will experience moderate-to-severe pain. This can have a major negative impact on their quality of life. Opioid (morphine-like) medications are commonly used to treat moderate or severe cancer pain, and are recommended for this purpose in the World Health Organization (WHO) pain treatment ladder. Pain is not sufficiently relieved by opioid medications in 10% to 15% of people with cancer. In people with insufficient relief of cancer pain, new analgesics are needed to effectively and safely supplement or replace opioids.

OBJECTIVES

To evaluate the benefits and harms of cannabis-based medicines, including medical cannabis, for treating pain and other symptoms in adults with cancer compared to placebo or any other established analgesic for cancer pain.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 26 January 2023.

SELECTION CRITERIA

We selected double-blind randomised, controlled trials (RCT) of medical cannabis, plant-derived and synthetic cannabis-based medicines against placebo or any other active treatment for cancer pain in adults, with any treatment duration and at least 10 participants per treatment arm.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. The primary outcomes were 1. proportions of participants reporting no worse than mild pain; 2. Patient Global Impression of Change (PGIC) of much improved or very much improved and 3. withdrawals due to adverse events. Secondary outcomes were 4. number of participants who reported pain relief of 30% or greater and overall opioid use reduced or stable; 5. number of participants who reported pain relief of 30% or greater, or 50% or greater; 6. pain intensity; 7. sleep problems; 8. depression and anxiety; 9. daily maintenance and breakthrough opioid dosage; 10. dropouts due to lack of efficacy; 11. all central nervous system adverse events. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We identified 14 studies involving 1823 participants. No study assessed the proportions of participants reporting no worse than mild pain on treatment by 14 days after start of treatment. We found five RCTs assessing oromucosal nabiximols (tetrahydrocannabinol (THC) and cannabidiol (CBD)) or THC alone involving 1539 participants with moderate or severe pain despite opioid therapy. The double-blind periods of the RCTs ranged between two and five weeks. Four studies with a parallel design and 1333 participants were available for meta-analysis. There was moderate-certainty evidence that there was no clinically relevant benefit for proportions of PGIC much or very much improved (risk difference (RD) 0.06, 95% confidence interval (CI) 0.01 to 0.12; number needed to treat for an additional beneficial outcome (NNTB) 16, 95% CI 8 to 100). There was moderate-certainty evidence for no clinically relevant difference in the proportion of withdrawals due to adverse events (RD 0.04, 95% CI 0 to 0.08; number needed to treat for an additional harmful outcome (NNTH) 25, 95% CI 16 to endless). There was moderate-certainty evidence for no difference between nabiximols or THC and placebo in the frequency of serious adverse events (RD 0.02, 95% CI -0.03 to 0.07). There was moderate-certainty evidence that nabiximols and THC used as add-on treatment for opioid-refractory cancer pain did not differ from placebo in reducing mean pain intensity (standardised mean difference (SMD) -0.19, 95% CI -0.40 to 0.02). There was low-certainty evidence that a synthetic THC analogue (nabilone) delivered over eight weeks was not superior to placebo in reducing pain associated with chemotherapy or radiochemotherapy in people with head and neck cancer and non-small cell lung cancer (2 studies, 89 participants, qualitative analysis). Analyses of tolerability and safety were not possible for these studies. There was low-certainty evidence that synthetic THC analogues were superior to placebo (SMD -0.98, 95% CI -1.36 to -0.60), but not superior to low-dose codeine (SMD 0.03, 95% CI -0.25 to 0.32; 5 single-dose trials; 126 participants) in reducing moderate-to-severe cancer pain after cessation of previous analgesic treatment for three to four and a half hours (2 single-dose trials; 66 participants). Analyses of tolerability and safety were not possible for these studies. There was low-certainty evidence that CBD oil did not add value to specialist palliative care alone in the reduction of pain intensity in people with advanced cancer. There was no difference in the number of dropouts due to adverse events and serious adverse events (1 study, 144 participants, qualitative analysis). We found no studies using herbal cannabis.

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that oromucosal nabiximols and THC are ineffective in relieving moderate-to-severe opioid-refractory cancer pain. There is low-certainty evidence that nabilone is ineffective in reducing pain associated with (radio-) chemotherapy in people with head and neck cancer and non-small cell lung cancer. There is low-certainty evidence that a single dose of synthetic THC analogues is not superior to a single low-dose morphine equivalent in reducing moderate-to-severe cancer pain. There is low-certainty evidence that CBD does not add value to specialist palliative care alone in the reduction of pain in people with advanced cancer.

Intranasal dexmedetomidine with morphine or tramadol: A comparative study of effects on alfaxalone requirements for anesthesia in cats

Background and Aim

Intranasal (IN) sedatives provide a non-invasive route for premedication drug administration. This study compared the cardiorespiratory and sparing effects of IN dexmedetomidine combined with morphine (DM) or tramadol (DT) on alfaxalone requirements for anesthesia induction in cats.

Materials and Methods

Twenty-four cats were randomly assigned to three groups: Dexmedetomidine combined morphine (IN dexmedetomidine 20 μg/kg plus 0.2 mg/kg morphine), DT (IN dexmedetomidine 20 μg/kg plus 1 mg/kg tramadol), or control (no premedication). The intravenous dose of 1% alfaxalone for endotracheal intubation was recorded with sedation scores, cardiorespiratory parameters (heart rate and respiration rate), and side effects.

Results

Both DM and DT were associated with significantly higher sedation scores than baseline, and sedation scores were found to be highest 20 min after premedication. Sedation scores were comparable between DM and DT groups. Side effects, including hypersalivation, vomiting, and pupillary dilation, were observed in the DM and DT groups. The dosage of alfaxalone required in the DM group (1.5 ± 0.3 mg/kg) was comparable to that of the DT group (2.0 ± 0.6 mg/kg, p = 0.0861), and both groups required significantly less alfaxalone than the control group (3.0 ± 0.6 mg/kg; p < 0.01). Heart and respiratory rates were comparable between the DM and DT groups. Duration of anesthesia in the control group (11 ± 4 min) was significantly shorter than in the DM (29 ± 5 min, p = 0.0016) and DT (38 ± 14 min, p < 0.001) groups.

Conclusion

Intranasal administration of DM or DT produces good sedation and offers an alternative, non-invasive route for cats undergoing general anesthesia.

Prenatal Morphine Exposure Increases Cardiovascular Disease Risk and Programs Neurogenic Hypertension in the Adult Offspring

BACKGROUND

The opioid overdose and opioid use disorder epidemics are concomitant with increased metabolic and CVD risk. Although opioid use disorder causes adverse pregnancy outcomes, the offspring's cardiovascular health is understudied. We hypothesized that offspring exposed to in utero morphine exposure (IUME) would show increased CVD risk factors and endogenous opioid system dysregulation.

METHODS

Sprague Dawley dams were treated with saline (vehicle, n=10) or escalating doses of morphine (5-20 mg/kg per day, SC, n=10) during gestation. Cardiovascular and metabolic parameters were assessed in adult offspring.

RESULTS

Litter size and pups' birth weight were not different in response to IUME. Female and male IUME offspring showed reduced body length at birth (P<0.05) and body weight from weeks 1 to 3 of life (P<0.05), followed by a catch-up growth effect. By week 16, female and male IUME rats showed reduced tibia length (P<0.05) and fat mass. IUME increases the mean arterial pressure and the depressor response to mecamylamine (5 mg/kg per day, IP) induced by IUME were abolished by a chronic treatment with an alpha-adrenergic receptor blocker (prazosin; 1 mg/kg per day, IP). Although circulating levels of angiotensin peptides were similar between groups, IUME exacerbated maximal ex vivo Ang (angiotensin) II-induced vasoconstriction (P<0.05) and induced endothelial dysfunction in a sex-specific manner (P<0.05). Proenkephalin, an endogenous opioid peptide that lowers blood pressure and sympathetic-mediated vasoconstriction, showed reduced mRNA expression in the heart, aorta, and kidneys from morphine versus vehicle group (P<0.05).

CONCLUSIONS

Among the effects of IUME, neurogenic hypertension, vascular dysfunction, and metabolic dysfunction could be associated with the dysregulation of the endogenous opioid system.

Knowledge, Perception and Barriers to Cancer Pain Management among Doctors in Malaysia

Background

Pain remains common in people living with advanced cancer and is often inadequately managed. This study was designed to assess knowledge, perceptions and barriers to morphine use in cancer pain management among doctors in Malaysia.

Methods

Doctors from multiple disciplines in a general hospital were invited to complete a 39-item self-reported questionnaire between November 2020 and December 2020. Each question was based on a 5-point Likert scale (1 = strongly disagree; 5 = strongly agree). 'Agree' and 'strongly agree' were considered correct or positive responses, except for nine questions worded in the opposite direction. Associations between variables were confirmed using Pearson's chi-squared and Fisher's exact tests.

Results

Most respondents were house officers (206/321; 64.2%) with less than two years of service, followed by medical officers (68/321; 21.2%) and specialists (47/321; 14.6%). Only 7.2% of the respondents had received formal palliative care training before the study. Of the respondents, 73.5% were aware of the World Health Organization (WHO) analgaesic ladder, 60.7% were correct on oral morphine as the first line for moderate to severe cancer pain treatment and 91.9% knew the need to add rescue morphine for breakthrough pain. Additionally, 34.0% (P < 0.001) perceived morphine use caused addiction, 57.9% (n = 186) expressed fear of respiratory depression and 18.3% of medical officers and specialists perceived limited access and a maximum dose to prescribe. There was a significant difference in knowledge and perception between junior doctors and senior clinicians. The majority strongly agreed and agreed that there were inadequate training opportunities in cancer pain management.

Conclusion

Inconsistent knowledge and negative perceptions of cancer pain management among doctors were demonstrated in this study.

Microglia NLRP3 Inflammasome and Neuroimmune Signaling in Substance Use Disorders

During the last decade, substance use disorders (SUDs) have been increasingly recognized as neuroinflammation-related brain diseases. Various types of abused drugs (cocaine, methamphetamine, alcohol, opiate-like drugs, marijuana, etc.) can modulate the activation status of microglia and neuroinflammation levels which are involved in the pathogenesis of SUDs. Several neuroimmune signaling pathways, including TLR/NF-кB, reactive oxygen species, mitochondria dysfunction, as well as autophagy defection, etc., have been implicated in promoting SUDs. Recently, inflammasome-mediated signaling has been identified as playing critical roles in the microglia activation induced by abused drugs. Among the family of inflammasomes, NOD-, LRR-, and pyrin-domain-containing protein 3 (NLRP3) serves the primary research target due to its abundant expression in microglia. NLRP3 has the capability of integrating multiple external and internal inputs and coordinately determining the intensity of microglia activation under various pathological conditions. Here, we summarize the effects of abused drugs on NLRP3 inflammasomes, as well as others, if any. The research on this topic is still at an infant stage; however, the readily available findings suggest that NLRP3 inflammasome could be a common downstream effector stimulated by various types of abused drugs and play critical roles in determining abused-drug-mediated biological effects through enhancing glia-neuron communications. NLRP3 inflammasome might serve as a novel target for ameliorating the development of SUDs.

Challenges of Access to Oral Morphine Medicine: Palliative Care at a Crossroads for Cancer Patients in Ethiopia

Ethiopia registers 77,352 new cases of cancer and 51,865 deaths every year, and the number is showing an increasing trend year to year. Despite the importance of providing palliative care, the country has a long way to go to match the needs of and provide relief for patients with cancer. The promotion and expansion of palliative care services is challenged by a number of problems, among which lack of access to pain-relieving medicine is one of, if not the main, problems raised by health professionals and by various parties involved in health care. Oral morphine is effective and the preferred pain-relieving medicine with tolerable side effects, especially when given by titrating the dose. However, Ethiopia is facing a shortage of oral morphine in health-care facilities and other places where the product is needed. Unless an immediate solution is sought to address the inaccessibility of this medicine, the problem of palliative care will be pronounced and the suffering of patients will continue.

Activation of neurons and satellite glial cells in the DRG produces morphine-induced hyperalgesia

Activation of neurons and glial cells in the dorsal root ganglion is one of the key mechanisms for the development of hyperalgesia. The aim of the present study was to examine the role of neuroglial activity in the development of opioid-induced hyperalgesia. Male rats were treated with morphine daily for 3 days. The resultant phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 in the dorsal root ganglion was analyzed by immunohistochemistry and Western blotting. Pain hypersensitivity was analyzed using behavioral studies. The amount of cytokine expression in the dorsal root ganglion was also analyzed. Repeated morphine treatment induced hyperalgesia and marked induction of phosphorylated ERK1/2 in the neurons and satellite glial cells on day 3. An opioid receptor antagonist, toll like receptor-4 inhibitor, MAP/ERK kinase (MEK) inhibitor and gap junction inhibitor inhibited morphine-induced hyperalgesia and ERK1/2 phosphorylation. Morphine treatment induced alteration of cytokine expression, which was inhibited by the opioid receptor antagonist, toll like receptor-4 inhibitor, MEK inhibitor and gap junction inhibitor. Dexamethasone inhibited morphine-induced hyperalgesia and ERK1/2 phosphorylation after morphine treatment. The peripherally restricted opioid receptor antagonist, methylnaltrexone, inhibited hyperalgesia and ERK1/2 phosphorylation. Morphine activates ERK1/2 in neurons and satellite glial cells in the dorsal root ganglion via the opioid receptor and toll like receptor-4. ERK1/2 phosphorylation is gap junction-dependent and is associated with the alteration of cytokine expression. Inhibition of neuroinflammation by activation of neurons and glia might be a promising target to prevent opioid-induced hyperalgesia.