Challenges of acute pain management in older patients.

Adequate management of acute pain in the older population is crucial. However, it is inherently complex because of multiple physiological changes that significantly impact both the pharmacokinetics and pharmacodynamics of medications. Current guidelines promote paracetamol as the first-line analgesic for acute pain in older adults, whereas opioids are advised cautiously for moderate to severe acute pain. However, opioids come with a significant array of side effects, which can be more pronounced in older individuals. Ketamine administered via intranasal (IN) and nebulised inhalation in the emergency department for managing acute pain in older patients shows promising potential for improving pain management and reducing opioid reliance Kampan, Thong-on, Sri-on (2024, Age Ageing, 53, afad255). Nebulised ketamine appears superior in terms of adverse event incidence. However, the adoption of IN or nebulised ketamine in older adult acute pain management remains unclear because of the lack of definitive conclusions and clear guidelines. Nevertheless, these modalities can be valuable options for patients where opioid analgesics are contraindicated or when intravenous morphine titration is impractical or contraindicated. Here, we review these concepts, the latest evidence and propose avenues for research.

A locus coeruleus to dorsal hippocampus pathway mediates cue-induced reinstatement of opioid self-administration in male and female rats.

Opioid use disorder is a chronic relapsing disorder encompassing misuse, dependence, and addiction to opioid drugs. Long term maintenance of associations between the reinforcing effects of the drug and the cues associated with its intake are a leading cause of relapse. Indeed, exposure to the salient drug-associated cues can lead to drug cravings and drug seeking behavior. The dorsal hippocampus (dHPC) and locus coeruleus (LC) have emerged as important structures for linking the subjective rewarding effects of opioids with environmental cues. However, their role in cue-induced reinstatement of opioid use remains to be further elucidated. In this study, we showed that chemogenetic inhibition of excitatory dHPC neurons during re-exposure to drug-associated cues significantly attenuates cue-induced reinstatement of morphine-seeking behavior. In addition, the same manipulation reduced reinstatement of sucrose-seeking behavior but failed to alter memory recall in the object location task. Finally, intact activity of tyrosine hydroxylase (TH) LC-dHPCTh afferents is necessary to drive cue induced reinstatement of morphine-seeking as inhibition of this pathway blunts cue-induced drug-seeking behavior. Altogether, these studies show an important role of the dHPC and LC-dHPCTh pathway in mediating cue-induced reinstatement of opioid seeking.

Efficacy of reconstituted intravenous fentanyl to sublingual solution versus oral morphine syrup for breakthrough pain among patients with chronic gynecologic cancer pain: A randomized, double-blind, placebo-controlled trial.

Rapid-acting fentanyl formulations are superior to oral morphine (OM) syrup in controlling breakthrough pain among patients with cancer, but they are expensive and unavailable in many countries. OBJECTIVE: To evaluate the efficacy of reconstituted intravenous fentanyl to sublingual solution (IFS) in relieving breakthrough pain as compared with OM. METHODS: In this randomized, double-blind, double-dummy, placebo-controlled trial, patients with gynecologic cancer aged ≥18 years experiencing chronic cancer pain with breakthrough pain were enrolled. Patients were randomly allocated (1:1) to receive either 50 µg IFS or 5 mg OM. Pain intensity level was assessed at 5, 15, 30, 45, 60, and 120 min after treatment. The primary outcome was the reduction in pain intensity at 15 min in the intention-to-treat population (ClinicalTrials.gov, NCT05037539). RESULTS: Between June 15, 2021 and December 30, 2021, 40 participants were equally and randomly assigned to receive IFS or OM. The primary outcome was significantly higher in the IFS group (4.25 vs. 1.05, p < 0.0001). The secondary outcomes also showed higher reduction in pain intensity at 5 min in the IFS group. Subsequent breakthrough pain did not differ between the two groups. However, the reduction in pain was lower in the IFS group at 45, 60, and 120 min, where pain was classified as mild. No severe adverse effects were observed in both groups. Burning sensation without noticeable lesion was found in 20% of the IFS group. CONCLUSION: IFS can reduce early breakthrough pain. IFS may be considered for breakthrough pain when rapid-acting fentanyl formulations are unavailable.

Postoperative effects and complications of intrathecal morphine compared to epidural analgesia in patients undergoing intracorporeal robot-assisted radical cystectomy: a retrospective study.

BACKGROUND: Analgesia after robot assisted radical cystectomy aims to reduce postoperative pain and opioid consumption, while facilitating early mobilization and enteral nutrition and minimizing complications. Epidural analgesia is currently recommended for an open radical cystectomy, but it is unclear if intrathecal morphine is a suiting, less-invasive alternative for a robot-assisted radical cystectomy. METHODS: The analgesic method of choice changed from epidural anesthesia to intrathecal anesthesia for patients undergoing a robot-assisted radical cystectomy. This single-center retrospective study aims to investigate if there is a difference between epidural and intrathecal analgesia in postoperative pain scores, opioid consumption, length of hospital stays and postoperative complications. An Propensity Matched Analysis was added to conventional analysis to consolidate the findings. RESULTS: The study population consisted of 153 patients of whom 114 received an epidural catheter with bupivacaine/sufentanil and 39 received a single shot of intrathecal bupivacaine/morphine. Mean pain scores on the first two postoperative days (POD) were slightly higher in the intrathecal analgesia group (epidural versus intrathecal analgesia, NRS POD0: 0(0-2)[0-8] versus 1(0-3)[0-5], p = 0.050; POD1: 2(1-3)[0-8] versus 3(1-4)[0-7], p = 0.058; POD2: 2(0-3)[0-8] versus 3(2-4)[0-7], p = 0.010). Total postoperative morphine consumption was similar over the first seven days: 15 mg (5-35)[0-148] in the epidural group versus 11 mg (0-35)[0-148] in the intrathecal morphine group, p = 0.167. Length of hospital stay and time until fit for discharge where slightly higher in the epidural group (respectively 7 days (5-9)[4-42] versus 6 days (5-7)[4-38], p = 0.006, and 5 days (4-8)[3-30]) versus 5 days (4-6)[3-34], p = 0.018). There was no further difference in postoperative course. CONCLUSIONS: This study showed that the effects of epidural analgesia and intrathecal morphine are comparable and that intrathecal morphine may be a suiting alternative for epidural analgesia.

Integrative Roles of Dopamine Pathway and Calcium Channels Reveal a Link between Schizophrenia and Opioid Use Disorder.

Several theories have been proposed to explain the mechanisms of substance use in schizophrenia. Brain neurons pose a potential to provide novel insights into the association between opioid addiction, withdrawal, and schizophrenia. Thus, we exposed zebrafish larvae at 2 days post-fertilization (dpf) to domperidone (DPM) and morphine, followed by morphine withdrawal. Drug-induced locomotion and social preference were assessed, while the level of dopamine and the number of dopaminergic neurons were quantified. In the brain tissue, the expression levels of genes associated with schizophrenia were measured. The effects of DMP and morphine were compared to vehicle control and MK-801, a positive control to mimic schizophrenia. Gene expression analysis revealed that α1C, α1Sa, α1Aa, drd2a, and th1 were up-regulated after 10 days of exposure to DMP and morphine, while th2 was down-regulated. These two drugs also increased the number of positive dopaminergic neurons and the total dopamine level but reduced the locomotion and social preference. The termination of morphine exposure led to the up-regulation of th2, drd2a, and c-fos during the withdrawal phase. Our integrated data implicate that the dopamine system plays a key role in the deficits in social behavior and locomotion that are common in the schizophrenia-like symptoms and opioid dependence.

Systemic opioid regimens for postoperative pain in neonates.

BACKGROUND: Postoperative pain clinical management in neonates has always been a challenging medical issue. Worldwide, several systemic opioid regimens are available for pediatricians, neonatologists, and general practitioners to control pain in neonates undergoing surgical procedures. However, the most effective and safe regimen is still unknown in the current body of literature. OBJECTIVES: To determine the effects of different regimens of systemic opioid analgesics in neonates submitted to surgery on all-cause mortality, pain, and significant neurodevelopmental disability. Potentially assessed regimens might include: different doses of the same opioid, different routes of administration of the same opioid, continuous infusion versus bolus administration, or 'as needed' administration versus 'as scheduled' administration. SEARCH METHODS: Searches were conducted in June 2022 using the following databases: Cochrane Central Register of Controlled Trials [CENTRAL], PubMed, and CINAHL. Trial registration records were identified via CENTRAL and an independent search of the ISRCTN registry. SELECTION CRITERIA: We included randomized controlled trials (RCTs), quasi-randomized, cluster-randomized, and cross-over controlled trials evaluating systemic opioid regimens' effects on postoperative pain in neonates (pre-term or full-term). We considered suitable for inclusion: I) studies evaluating different doses of the same opioid; 2) studies evaluating different routes of administration of the same opioid; 3) studies evaluating the effectiveness of continuous infusion versus bolus infusion; and 4) studies establishing an assessment of an 'as needed' administration versus 'as scheduled' administration. DATA COLLECTION AND ANALYSIS: According to Cochrane methods, two investigators independently screened retrieved records, extracted data, and appraised the risk of bias. We stratified meta-analysis by the type of intervention: studies evaluating the use of opioids for postoperative pain in neonates through continuous infusion versus bolus infusion and studies assessing the 'as needed' administration versus 'as scheduled' administration. We used the fixed-effect model with risk ratio (RR) for dichotomous data and mean difference (MD), standardized mean difference (SMD), median, and interquartile range (IQR) for continuous data. Finally, we used the GRADEpro approach for primary outcomes to evaluate the quality of the evidence across included studies. MAIN RESULTS: In this review, we included seven randomized controlled clinical trials (504 infants) from 1996 to 2020. We identified no studies comparing different doses of the same opioid, or different routes. The administration of continuous opioid infusion versus bolus administration of opioids was evaluated in six studies, while one study compared 'as needed' versus 'as scheduled' administration of morphine given by parents or nurses. Overall, the effectiveness of continuous infusion of opioids over bolus infusion as measured by the visual analog scale (MD 0.00, 95% confidence interval (CI) -0.23 to 0.23; 133 participants, 2 studies; I² = 0); or using the COMFORT scale (MD -0.07, 95% CI -0.89 to 0.75; 133 participants, 2 studies; I² = 0), remains unclear due to study designs' limitations, such as the unclear risk of attrition, reporting bias, and imprecision among reported results (very low certainty of the evidence).  None of the included studies reported data on other clinically important outcomes such as all-cause mortality rate during hospitalization, major neurodevelopmental disability, the incidence of severe retinopathy of prematurity or intraventricular hemorrhage, and cognitive- and educational-related outcomes.  AUTHORS' CONCLUSIONS: Limited evidence is available on continuous infusion compared to intermittent boluses of systemic opioids. We are uncertain whether continuous opioid infusion reduces pain compared with intermittent opioid boluses; none of the studies reported the other primary outcomes of this review, i.e. all-cause mortality during initial hospitalization, significant neurodevelopmental disability, or cognitive and educational outcomes among children older than five years old. Only one small study reported on morphine infusion with parent- or nurse-controlled analgesia.

Does slow release oral morphine have impact on craving and impulsivity in heroin dependent individuals?

Craving and impulsivity are addiction components which explain why heroin-dependant individuals (HDI), continue using heroin despite not wanting to do so. Opioid maintenance treatment (OMT), such as slow-release oral morphine (SROM), is the most effective treatment for opioid dependence. However, the impact of SROM on craving and impulsivity remains unclear. In this observational study, 23 HDI receiving SROM, their usual OMT, took part in the experiment. Each of the participants filled in the perceived level of craving with a visual analog scale. Their impulsivity was assessed via three laboratory tasks, the stop-signal reaction time, the Balloon Analogue Risk Task and delay discounting. Each evaluation was performed before and after SROM administration. Craving was significantly reduced after administration of SROM (difference 2.83; P = 0.0010), whereas there were no significant differences in performance in the three laboratory tasks. In the long term, we observed an improvement on delay discounting correlated with the duration and dosage of SROM. The acute impact of SROM appears to significantly reduce craving, without impacting impulsivity. Observation of the correlation between delay discounting and the duration and dosage of OMT is of great interest and should be studied further.

Randomized Clinical Trial Comparing Quadratus Lumborum Block and Intrathecal Morphine for Postcesarean Analgesia / Ensaio Clínico Randomizado Comparando Bloqueio do Quadrado Lombar e Morfina Intratecal Para Analgesia Pós-cesariana

Abstract Objective To compare the efficacy of quadratus lumborum (QL) block and intrathecal morphine (M) for postcesarean delivery analgesia. Methods Thirty-one pregnant women with ≥ 37 weeks of gestation submitted to elective cesarean section were included in the study. They were randomly allocated to either the QL group (12.5 mg 0.5% bupivacaine for spinal anesthesia and 0.3 ml/kg 0.2% bupivacaine for QL block) or the M group (12.5 mg bupivacaine 0.5% and 100 mcg of morphine in spinal anesthesia). The visual analog scale of pain, consumption of morphine and tramadol for pain relief in 48 hours, and side effects were recorded. Results Median pain score and/or pain variation were higher in the morphine group than in the QL group (p = 0.02). There was no significant difference in the consumption of morphine or tramadol between groups over time. Side effects such as pruritus, nausea, and vomiting were observed only in the morphine group. Conclusion Quadratus lumborum block and intrathecal morphine are effective for analgesia after cesarean section. Patients undergoing QL block had lower postoperative pain scores without the undesirable side effects of opioids such as nausea, vomiting, and pruritus.

Resumo Objetivo Comparar a eficácia do bloqueio do quadrado lombar (QL) e da morfina intratecal (M) na analgesia pós-cesariana. Métodos Trinta e uma gestantes com ≥ 37 semanas de gestação submetidas a cesariana eletiva foram incluídas no estudo. Eles foram alocados aleatoriamente no grupo QL (12,5 mg de bupivacaína a 0,5% para raquianestesia e 0,3 ml/kg de bupivacaína a 0,2% para bloqueio de QL) ou no grupo M (12,5 mg de bupivacaína a 0,5% e 100 mcg de morfina na raquianestesia). A escala visual analógica de dor, consumo de morfina e tramadol para alívio da dor em 48 horas e efeitos colaterais foram registrados. Resultados A mediana do escore de dor e/ou variação da dor foi maior no grupo morfina do que no grupo QL (p = 0,02). Não houve diferença significativa no consumo de morfina ou tramadol entre os grupos ao longo do tempo. Efeitos colaterais como prurido, náuseas e vômitos foram observados apenas no grupo morfina. Conclusão O bloqueio QL e a morfina intratecal são eficazes para analgesia após cesariana. Os pacientes submetidos ao bloqueio do QL apresentaram menores escores de dor pós-operatória sem os efeitos colaterais indesejáveis dos opioides, como náuseas, vômitos e prurido.

Effect of Regular, Low-Dose, Extended-release Morphine on Chronic Breathlessness in Chronic Obstructive Pulmonary Disease: The BEAMS Randomized Clinical Trial.

Importance: Chronic breathlessness is common in people with chronic obstructive pulmonary disease (COPD). Regular, low-dose, extended-release morphine may relieve breathlessness, but evidence about its efficacy and dosing is needed. Objective: To determine the effect of different doses of extended-release morphine on worst breathlessness in people with COPD after 1 week of treatment. Design, Setting, and Participants: Multicenter, double-blind, placebo-controlled randomized clinical trial including people with COPD and chronic breathlessness (defined as a modified Medical Research Council score of 3 to 4) conducted at 20 centers in Australia. People were enrolled between September 1, 2016, and November 20, 2019, and followed up through December 26, 2019. Interventions: People were randomized 1:1:1 to 8 mg/d or 16 mg/d of oral extended-release morphine or placebo during week 1. At the start of weeks 2 and 3, people were randomized 1:1 to 8 mg/d of extended-release morphine, which was added to the prior week's dose, or placebo. Main Outcomes and Measures: The primary outcome was change in the intensity of worst breathlessness on a numerical rating scale (score range, 0 [none] to 10 [being worst or most intense]) using the mean score at baseline (from days -3 to -1) to the mean score after week 1 of treatment (from days 5 to 7) in the 8 mg/d and 16 mg/d of extended-release morphine groups vs the placebo group. Secondary outcomes included change in daily step count measured using an actigraphy device from baseline (day -1) to the mean step count from week 3 (from days 19 to 21). Results: Among the 160 people randomized, 156 were included in the primary analyses (median age, 72 years [IQR, 67 to 78 years]; 48% were women) and 138 (88%) completed treatment at week 1 (48 in the 8 mg/d of morphine group, 43 in the 16 mg/d of morphine group, and 47 in the placebo group). The change in the intensity of worst breathlessness at week 1 was not significantly different between the 8 mg/d of morphine group and the placebo group (mean difference, -0.3 [95% CI, -0.9 to 0.4]) or between the 16 mg/d of morphine group and the placebo group (mean difference, -0.3 [95%, CI, -1.0 to 0.4]). At week 3, the secondary outcome of change in mean daily step count was not significantly different between the 8 mg/d of morphine group and the placebo group (mean difference, -1453 [95% CI, -3310 to 405]), between the 16 mg/d of morphine group and the placebo group (mean difference, -1312 [95% CI, -3220 to 596]), between the 24 mg/d of morphine group and the placebo group (mean difference, -692 [95% CI, -2553 to 1170]), or between the 32 mg/d of morphine group and the placebo group (mean difference, -1924 [95% CI, -47 699 to 921]). Conclusions and Relevance: Among people with COPD and severe chronic breathlessness, daily low-dose, extended-release morphine did not significantly reduce the intensity of worst breathlessness after 1 week of treatment. These findings do not support the use of these doses of extended-release morphine to relieve breathlessness. Trial Registration: ClinicalTrials.gov Identifier: NCT02720822.

Administración prolongada de morfina intratecal por bomba de infusión implantada, en un caso de dolor crónico no oncológico / Prolonged administration of intratecal morphine by infusion pump implanted in a case of non-oncological chronic pain / Administração prolongada de morfina intratecal por bomba de infusão implantada, em caso de dor crônica não oncológica

Introducción: Se describe la evolución de un paciente que recibe morfina intratecal mediante una bomba de infusión, que le fuera implantada hace 14 años para tratamiento de su dolor lumbar crónico post-laminectomía. Material y método: Requería la administración de 60 mg/día de morfina subcutánea que le provocaban efectos secundarios que no toleraba, y múltiples internaciones para control del dolor. Se le implantó una bomba de infusión continua (Isomed) conectada a un catéter subaracnoideo, que libera 1 ml/día, y requiere ser llenada cada 60 días. Resultados: Se observó una disminución del dolor promedio de 50% al año, y de 75% a los 6 y 14 años. Requirió un aumento progresivo de las dosis de llenado, que pasaron de 30 mg de morfina (0.5 mg/día) al inicio, a 40 mg de morfina (0.66 mg /día) al año, a 70 mg de morfina (1.16 mg/día) a los 6 años, a 140 mg (2.33 mg/día) a los 14 años. No se registraron complicaciones médicas graves. Mantuvo constipación y sudoración durante todo el período, e instaló un hipogonadismo secundario con trastornos de la libido y de la erección que fueron corregidos con la administración de testosterona. No requirió más internaciones por dolor. No se observaron complicaciones relacionadas con el funcionamiento o llenado de la bomba, ni vinculadas al catéter. El paciente manifestó estar satisfecho con el implante. Discusión: A pesar del aumento de las dosis de llenado, expresión del desarrollo de tolerancia, las dosis de morfina/día requeridas son francamente inferiores al límite recomendado. Conclusiones: El balance del riesgo-beneficio del implante resultó positivo, considerando el mejor control del dolor logrado, las menores dosis de morfina utilizadas, así como la ausencia de complicaciones graves y de internaciones para control del dolor.

Introduction: The evolution of a patient receiving intrathecal morphine through an infusion pump that was implanted 14 years ago for the treatment of chronic post-laminectomy low back pain is described. Material and method: It required the administration of 60 mg / day of subcutaneous morphine that caused side effects that did not tolerate, and multiple hospitalizations for pain control. He was implanted with a continuous infusion pump (Isomed) connected to a subarachnoid catheter, which releases 1 ml / day, and needs to be filled every 60 days. Results: An average pain decrease of 50% per year, and 75% at 6 and 12 years was observed. It required a progressive increase in filling doses, which went from 30 mg of morphine (0.5 mg / day) at the beginning, to 40 mg of morphine (0.66 mg / day at the first year, to 70 mg of morphine (1.16 mg / day) at the sixth year, at 140 mg (2.33 mg / day) at the fourteen year. No serious medical complications were recorded, he maintained constipation and sweating throughout the period, and installed secondary hypogonadism with libido and erection disorders, that were corrected with the administration of testosterone. No further hospitalizations were required due to pain. No complications were observed related to the operation or filling of the pump or linked to the catheter. The patient stated that he was satisfied with the implant. Discussion: Despite the increase in filling doses, expression of tolerance development, the required morphine / day doses are frankly below the recommended limit. Conclusions: The risk-benefit balance of the implant was positive, considering the best pain control, the lowest doses used, the absence of serious complications, and the lack of hospitalizations for pain control.

Introdução: Descreve-se a evolução de um paciente que recebeu morfina intratecal através de uma bomba de infusão, implantada há 14 anos para o tratamento de lombalgia crônica pós-laminectomia. Material e método: Necessitou de administração de 60 mg/dia de morfina por via subcutânea, que provocou efeitos colaterais intolerantes, e múltiplas internações para controle da dor. Foi implantada uma bomba de infusão contínua (Isomed) conectada a um cateter subaracnóideo, que libera 1 ml/dia, necessitando de reenchimento a cada 60 dias. Resultados: Observou-se redução média da dor de 50% em um ano e 75% em 6 e 14 anos. Foi necessário um aumento progressivo das doses de enchimento, que passaram de 30 mg de morfina (0,5 mg/dia) no início, para 40 mg de morfina (0,66 mg/dia) por ano, para 70 mg de morfina (1,16 mg/dia) dia) aos 6 anos, para 140 mg (2,33 mg/dia) aos 14 anos. Não foram registradas complicações médicas graves. Manteve constipação e sudorese durante todo o período e desenvolveu hipogonadismo secundário com distúrbios de libido e ereção que foram corrigidos com administração de testosterona. Ele não necessitou de mais hospitalizações por dor. Não foram observadas complicações relacionadas à operação ou enchimento da bomba, ou relacionadas ao cateter. O paciente afirmou estar satisfeito com o implante. Discussão: Apesar do aumento das doses de enchimento, expressão do desenvolvimento da tolerância, as doses necessárias de morfina/dia são francamente inferiores ao limite recomendado. Conclusões: A relação risco-benefício do implante foi positiva, considerando o melhor controle da dor alcançado, as menores doses de morfina utilizadas, bem como a ausência de complicações graves e internações para controle da dor.

Estudio cuasi experimental: analgesia intratecal Clonidina vs Morfina para manejo del dolor postoperatorio inmediato en cirugías de columna / QUASI-EXPERIMENTAL STUDY: CLONIDINE INTRATHECAL ANESTHESIA VS. MORPHINE FOR IMMEDIATE POSTOPERATIVE PAIN MANAGEMENT IN SPINE SURGERY

Introducción: El manejo inmediato del dolor postoperatorio es esencial para una comodidad y rehabilitación temprana del paciente Este estudio busca evaluar el efecto analgésico postoperatorio inmediato en cirugías de columna lumbosacra por vía posterior, como los efectos adversos con la administración de analgesia intratecal, usando Clonidina contra Morfina. Material y métodos: Es un estudio analítico de intervención, cuasi experimental, prospectivo, longitudinal, comparativo, doble ciego. Para comparar la eficacia de la analgesia intratecal post operatoria inmediata en cirugías de columna lumbosacra primarias por vía posterior y los efectos adversos. Los pacientes se distribuyeron en dos grupos previamente designados, a un grupo se le administro Clonidina 0.5 microgramos/kg/peso y a otro grupo Morfina 5 microgramos/Kg/Peso. intratecal, intraoperatorio. Resultados: Existió diferencia estadísticamente significativa con mejor manejo del dolor postoperatorio en las primeras horas y menor presencia de vómitos en el grupo de pacientes que se utilizó Clonidina intratecal. No existió diferencia estadísticamente significativa de ambas medicaciones intratecales en la valoración de otros efectos adversos. Discusión: El uso de la analgesia intratecal ha ido ganando relevancia en el tiempo y se fueron sumando estudios para ver la eficacia de diferentes medicamentos, diferentes dosis, menor presencia de efectos adversos. El estudio analiza estas variables buscando una mejor opción terapéutica. Tenemos a favor una muestra representativa a pesar de no ser aleatoria, estricto seguimiento, y análisis estadístico adecuado. Conclusión: La Clonidina intratecal es más efectiva para manejo del dolor post operatorio inmediato de cirugías de columna lumbosacra por vía posterior y con menor presencia de efectos adversos

Introduction: Immediate postoperative pain management is essential for the patient's greater comfort and early rehabilitation. Te goal of this study is to evaluate the immediate analgesic postoperative effect in posterior lumbosacral spine surgery, as well as the adverse effects of the administration of intrathecal analgesia, using Clonidine versus Morphine. Material and methods: An analytical, quasi-experimental, prospective, longitudinal, comparative, double-blinded intervention study was conducted to compare the efficacy of immediate postoperative intrathecal analgesia in primary posterior lumbosacral spine surgery, and the adverse effects. Te patients were divided into two previously designated groups. One group received Clonidine 0.5 microgramos/kg and the other group received Morphine 5 microgramos/kg. Intrathecal, intraoperative. Results: Tere was a statistically significant difference with better postoperative pain management in the first hours and less vomiting in the group of patients who received intrathecal Clonidine. Tere was no statistically significant difference between both intrathecal medications in the evaluation of other adverse effects. Discussion: Te use of intrathecal analgesia, has been on the rise over time and more studies have been conducted to see the efficacy of different drugs, different doses, with fewer adverse effects. Tis study to analyze these variables with a view to finding a better therapeutic option. Te advantage is having a representative if not random sample, strict follow-up, and appropriate statistical analysis Conclusion: Intrathecal Clonidine proved to be more effective in immediate postoperative pain management after posterior lumbosacral spine surgery and with fewer adverse effects

Effect of dexamethasone as an analgesic adjuvant to multimodal pain treatment after total knee arthroplasty: randomised clinical trial.

OBJECTIVE: To investigate the effects of one and two doses of intravenous dexamethasone in patients after total knee arthroplasty. DESIGN: Randomised, blinded, placebo controlled trial with follow-up at 90 days. SETTING: Five Danish hospitals, September 2018 to March 2020. PARTICIPANTS: 485 adult participants undergoing total knee arthroplasty. INTERVENTION: A computer generated randomised sequence stratified for site was used to allocate participants to one of three groups: DX1 (dexamethasone (24 mg)+placebo); DX2 (dexamethasone (24 mg)+dexamethasone (24 mg)); or placebo (placebo+placebo). The intervention was given preoperatively and after 24 hours. Participants, investigators, and outcome assessors were blinded. All participants received paracetamol, ibuprofen, and local infiltration analgesia. MAIN OUTCOME MEASURES: The primary outcome was total intravenous morphine consumption 0 to 48 hours postoperatively. Multiplicity adjusted threshold for statistical significance was P<0.017 and minimal important difference was 10 mg morphine. Secondary outcomes included postoperative pain. RESULTS: 485 participants were randomised: 161 to DX1, 162 to DX2, and 162 to placebo. Data from 472 participants (97.3%) were included in the primary outcome analysis. The median (interquartile range) morphine consumptions at 0-48 hours were: DX1 37.9 mg (20.7 to 56.7); DX2 35.0 mg (20.6 to 52.0); and placebo 43.0 mg (28.7 to 64.0). Hodges-Lehmann median differences between groups were: -2.7 mg (98.3% confidence interval -9.3 to 3.7), P=0.30 between DX1 and DX2; 7.8 mg (0.7 to 14.7), P=0.008 between DX1 and placebo; and 10.7 mg (4.0 to 17.3), P<0.001 between DX2 and placebo. Postoperative pain was reduced at 24 hours with one dose, and at 48 hours with two doses, of dexamethasone. CONCLUSION: Two doses of dexamethasone reduced morphine consumption during 48 hours after total knee arthroplasty and reduced postoperative pain. TRIAL REGISTRATION: Clinicaltrials.gov NCT03506789.

Trends in Opioid Use Among Cancer Patients in the United States: 2013-2018.

Background: In response to the US opioid epidemic, the Centers for Disease Control and Prevention updated their guideline on prescription opioids for chronic pain management in March 2016. The aim of this study was to provide detailed analysis of trends in opioid claims among cancer patients in the United States during 2013-2018. Methods: We analyzed pharmaceutical dispensing data from Symphony Health's Integrated Dataverse database, which covers approximately 80% of the US population. We examined annual trends in dispensed opioids in cancer patients during 2013-2018. We examined quarterly trends of the prevalence, mean number of days, and dose (stated as morphine milligram equivalents) of opioid dispensing in cancer patients. Results: Dispensing records of an average of over 3.7 million cancer patients contributed to the study annually in 2013-2018. The annual prevalence of opioid dispensing claims declined from 40.2% in 2013 to 34.5% in 2018. Annual declines occurred across cancer sites, and particularly among patients with metastatic cancer (decline of 19.8%), breast cancer (18.2%), and lung cancer (13.8%). By quarter, the prevalence of opioid claims declined statistically significantly from 26.6% in Q1 2013 to 21.2% in Q4 2018; this decline was more pronounced after Q3 2016 (2-sided P = .004). Both quarterly trends in mean days and morphine milligram equivalents of opioids supplied showed a gradual decline from 2013 to 2018, with a slightly larger decline after 2016. Conclusions: We observed a decline in opioid use among cancer patients, particularly after 2016, coinciding with the publication of the Centers for Disease Control and Prevention's guideline on prescription opioids for chronic pain management.

Efficacy of perioperative pharmacological and regional pain interventions in adult spine surgery: a network meta-analysis and systematic review of randomised controlled trials.

BACKGROUND: Development of a widely accepted standardised analgesic pathway for adult spine surgery has been hampered by the lack of quantitative analysis. We conducted a systematic review and network meta-analysis (NMA) to compare, rank, and grade all pharmacological and regional interventions used in adult spine surgery. METHODS: A systematic search was performed in January 2021. We performed double study screening, selection, and data extraction. The co-primary outcomes were cumulative morphine consumption (mg) and visual analogue pain score (range 0-10) at postoperative 24 h. An NMA was performed using the Bayesian approach (random effects model). We also ranked and graded all analgesic interventions using the Grading of Recommendations Assessment, Development and Evaluation approach for NMA. RESULTS: We screened 5908 studies and included 86 randomised controlled studies, which comprised 6284 participants. Of 20 pharmacological and 10 regional interventions, the most effective intervention was triple-drug therapy, consisting of paracetamol, nonsteroidal anti-inflammatory drugs, and adjunct. The pooled mean reduction in morphine consumption and pain score at postoperative 24 h were -26 (95% credible interval [CrI]: -39 to -12) mg and -2.3 (95% CrI: -3.1 to -1.4), respectively. Double-drug therapy was less effective, but showed moderate morphine reduction in a range of -15 to -17 mg and pain score reduction in a range of -1 to -1.6. Single-agent interventions were largely ineffective. CONCLUSIONS: Triple-drug therapy is the most effective pain intervention in adult spine surgery with moderate-to-high certainty of evidence. We have also identified a graded analgesic effect, in which analgesic efficacy increased with the number of multimodal drugs used. SYSTEMATIC REVIEW REGISTRATION: PROSPERO (CRD42020171326).

The effect of mitragynine on extracellular activity of brain dopamine and its metabolites.

Kratom, derived from the plant Mitragyna speciosa (M. speciosa) Korth is a traditional psychoactive preparation widely used in Southeast Asia and increasingly in the rest of the world. Use and abuse of Kratom preparations can be attributed to mitragynine (MIT), the main psychoactive compound isolated from its leaves. While MIT may have beneficial effects as a recreational drug, for pain management, and for opiate withdrawal, it may have an addiction potential at higher doses. However, its action in the reward system of the brain is currently unknown. This study investigated how mitragynine (10 mg/kg, i.p.) affects extracellular activity of dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the prefrontal cortex (PFC), nucleus accumbens (NAc) and caudate putamen (CPu) of the brain, compared to morphine (MOR; 10 mg/kg, i.p.) and methamphetamine (METH; 10 mg/kg, i.p.). Using in-vivo microdialysis in freely moving rats, we found a significant increase of extracellular DA after MOR and METH, but not after MIT in all three brain regions. MIT led to a significant increase of DOPAC and/or HVA in these brain regions while MOR and METH had only moderate effects. These findings suggest a strong and prolonged effect of MIT on DA synthesis/metabolism, but not on extracellular DA activity, which may limit the addiction risk of MIT, in contrast to MOR and METH.

Pharmacokinetic modeling of morphine and its glucuronides: Comparison of nebulization versus intravenous route in healthy volunteers.

Intravenous (i.v.) morphine is a safe, robust, and recommended treatment for severe pain using the titration principle. Despite its high efficacy, it is impacted by organizational constraints related to venous access. Nebulized (NEB) morphine may represent an alternative for titration but pharmacokinetic (PK) properties of short nebulization using routine devices need evaluation. Twenty-seven healthy volunteers were included to receive NEB or i.v. morphine administration using increasing amounts according to Dixon's reference method. Plasma morphine, morphine-3-glucuronide (M3G), and morphine-6-glucuronide (M6G) were quantified. PK modeling and simulations were performed using Monolix. Dixon's method exhibited a significantly higher morphine dose regimen in the NEB group versus the i.v. group (6.2 [5.3-7.1] vs. 3.0 [2.0-4.0] mg, p < 0.001). Morphine, M3G, and M6G dose-normalized exposure were significantly lower in the NEB group versus the i.v. group: morphine (19 [13-23] vs. 1044 [702-1266] µg min/L, p < 0.001), M3G (245 [162-287] vs. 3752 [2487-5165] µg min/L, p < 0.001) and M6G (28 [21-43] vs. 466 [370-723] µg min/L, p < 0.001). The model that best fitted the data consisted in a transit compartment for morphine absorption, three compartments for morphine distribution followed by multiple transit compartments (8.2 and 57.5-min transit time for M3G and M6G, respectively) and a first order elimination for M3G and M6G. Morphine bioavailability in the NEB group was 3.5% using the i.v. group as reference. Administration route and sex significantly influenced morphine and metabolite PKs. This work aimed to evaluate the PKs of NEB morphine compared with the i.v. route. Despite a bioavailability to improve, NEB morphine administration using a routine device is suitable to plan morphine titration.

No significant influence of OCT1 genotypes on the pharmacokinetics of morphine in adult surgical patients.

We investigated the impact of genetic variants in OCT1 (SLC22A1) on morphine, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) pharmacokinetics in adult patients scheduled for major surgery. Blood samples were taken before and 5, 10, 15, 30, 45, 60 and 90 min after a bolus of morphine (0.15 mg/kg). Patients were genotyped for the genetic variants (rs12208357, rs34059508, rs72552763 and rs34130495) in OCT1. Eighty-six patients completed the trial. The mean difference (95% confidence interval) for dose adjusted morphine, M3G and M6G AUC was 0.9 (-0.7-2.4), -5.9 (-11.8 to -0.03) and -1.1 (-2.5-0.4) h/L*10-6 , respectively, in patients with two reduced function alleles compared to patients with no reduced function alleles in OCT1. Accordingly, the (AUCM3G/Dose )/(AUCmorphine/Dose ) and (AUCM6G/Dose )/(AUCmorphine/Dose ) ratio was reduced, -1.8 (-3.2 to -0.4) and -0.4 (-0.7 to -0.03), respectively, when comparing the same groups. OCT1 variants had no influence on the experience of pain, adverse events or the number of PCA doses used. In conclusion, genetic variants in OCT1 had a small and clinically unimportant impact on the exposure of morphine after intravenous administration. Our results do not support pre-emptive genotyping for OCT1 prior to morphine administration in patients scheduled for major surgery.

Persistent effects of the orexin-1 receptor antagonist SB-334867 on naloxone precipitated morphine withdrawal symptoms and nociceptive behaviors in morphine dependent rats.

AIM OF THE STUDY: In this study, we investigated the effect of long-term administration of orexin receptor 1 (OXR1) antagonist on naloxone-precipitated morphine withdrawal symptoms and nociceptive behaviors in morphine-dependent rats. MATERIALS AND METHODS: Wistar rats received subcutaneous (s.c.) injections of morphine (6, 16, 26, 36, 46, 56, and 66 mg/kg, 2 ml/kg) at an interval of 24 h for 7 days. In chronic groups, the OXR1 antagonist, SB-334867 (20 mg/kg, i.p.), or its vehicle, was injected repetitively from postnatal day 1 (PND1)-PND23 and then for the following seven days before each morphine injection. Meanwhile, in acute groups, SB-334867, or its vehicle, was administered before each morphine injection. In groups of rats that were designated for withdrawal experiments, naloxone (2.5 mg/kg, i.p.) was administered after the last injection of morphine. In the formalin-induced pain, the effect of OXR1 inhibition on the antinociceptive effects of morphine was measured by injecting formalin after the final morphine injection. RESULTS: Animals that received long-term SB-334867 administration before morphine injection demonstrated a significant reduction in chewing, defecation, diarrhea, grooming, teeth chattering, wet-dog shake, and writhing. Inhibiting OXR1 for a long time increased formalin-induced nociceptive behaviors in interphase and phase II of the formalin-induced pain. CONCLUSIONS: Our results indicated that the inhibition of OXR1 significantly reduces the development of morphine dependence and behavioral signs elicited by the administration of naloxone in morphine-dependent rats. Furthermore, the prolonged blockade of OXR1 might be involved in formalin-induced nociceptive behaviors.

Quantifying the Pharmacodynamics of Morphine in the Treatment of Postoperative Pain in Preverbal Children.

While the pharmacokinetics of morphine in children have been studied extensively, little is known about the pharmacodynamics of morphine in this population. Here, we quantified the concentration-effect relationship of morphine for postoperative pain in preverbal children between 0 and 3 years of age. For this, we applied item response theory modeling in the pharmacokinetic/pharmacodynamic analysis of COMFORT-Behavior (COMFORT-B) scale data from 2 previous clinical studies. In the model, we identified a sigmoid maximal efficacy model for the effect of morphine and found that in 26% of children, increasing morphine concentrations were not associated with lower pain scores (nonresponders to morphine up-titration). In responders to morphine up-titration, the COMFORT-B score slowly decreases with increasing morphine concentrations at morphine concentrations >20 ng/mL. In nonresponding children, no decrease in COMFORT-B score is expected. In general, lower baseline COMFORT-B scores (2.1 points on average) in younger children (postnatal age <10.3 days) were found. Based on the model, we conclude that the percentage of children at a desirable COMFORT-B score is maximized at a morphine concentration between 5 and 30 ng/mL for children aged <10 days, and between 5 and 40 ng/mL for children >10 days. These findings support a dosing regimen previously suggested by Krekels et al, which would put >95% of patients within this morphine target concentration range at steady state. Our modeling approach provides a promising platform for pharmacodynamic research of analgesics and sedatives in children.

Otologic opioid usage and pain control in the postoperative period: An observational prospective study.

PURPOSE: Evaluate opioid prescribing patterns, opioid consumption, and patient pain patterns following otologic surgery. MATERIALS AND METHODS: Patients were included if they were ≥18 years old and received otologic surgery between November 2019 and August 2020. Patients were provided a survey which included a visual analog scale for recording their pain postoperatively and the amount of opioid they had remaining. Patients who did not complete all portions of the survey were excluded. RESULTS: Ninety-one patients completed the post-operative questionnaire. Collectively, patients were prescribed 5797 morphine milligram equivalents and used 3092: approximately 47% went unused. Of patients receiving a transcanal incision (n = 28/91, 31%), 70% went unused, whereas patients receiving a postauricular incision (n = 57/91, 63%), 38% went unutilized. The utilization difference between transcanal and postauricular cohorts was significant (p = 0.002). On multivariate analysis, patients who received a postauricular incision had 60% more opioid usage (p < 0.001), whereas those with a transcanal incision had an average reduction of 40% in opioid usage (p < 0.001). CONCLUSIONS: A significant amount of opioid medication went unused in this study. Patients with postauricular incisions had significantly increased opioid utilization as compared to those with transcanal incisions. Otologists may be able to successfully manage pain in the postoperative period with a reduced opioid prescription multimodal analgesia and increased patient education. Further study is needed to support this suggestion.