Intravenous Methadone versus Intrathecal Morphine as Part of an Enhanced Recovery After Cardiac Surgery Protocol on Postoperative Pain and Outcomes: A Retrospective Cohort Study.

OBJECTIVES: Evaluate the effect of intravenous (IV) methadone versus intrathecal morphine (ITM) within an Enhanced Recovery After Cardiac Surgery (ERACS) pathway on postoperative pain and outcomes (length of hospital stay and postoperative complications) after cardiac surgery. DESIGN: Retrospective cohort study. SETTING: Two tertiary academic medical institutions within the same health system. PARTICIPANTS: Eligible 289 adult patients undergoing elective cardiac surgery with an enhanced recovery pathway from January 2020 through July 2021. INTERVENTIONS: Patients were administered ITM (0.25 mg) or IV methadone (0.1 mg/kg) if ITM was contraindicated. All patients were enrolled in an ERACS pathway using current Enhanced Recovery After Surgery society guidelines. MEASUREMENTS AND MAIN RESULTS: Primary outcome measures included postoperative pain scores and opioid consumption measured as oral morphine equivalents. We analyzed patient demographics, procedural factors, intraoperative medications, and outcomes. Adjusted linear mixed models were fit to analyze associations between intervention and pain outcomes. ITM was associated with decrease in pain scores on postoperative day 0 after adjusting for clinical variables (average marginal effect, 0.49; 95% confidence interval, 0.002-0.977; p = 0.049). No difference in opioid consumption could be demonstrated between groups after adjusting for postoperative day and other variables of interest. CONCLUSIONS: ITM when compared with IV methadone was associated with a decrease in pain scores without any difference in opioid consumption after elective cardiac surgery. Methadone can be considered as a safe and effective alternative to ITM for ERACS protocols. Future large prospective studies are needed to validate this finding and further improve analgesia and safety.

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

OBJECTIVES: The aim of this study was to compare the analgesic efficacy and the effect on physiological variables and behavior of the use of tramadol, methadone and morphine as preoperative analgesia in healthy cats undergoing elective ovariohysterectomy. METHODS: Cats undergoing ovariohysterectomy were randomly assigned to receive one of the following premedication treatments intramuscularly: methadone (0.2 mg/kg; n = 10); morphine (0.2 mg/kg; n = 10); or tramadol (3 mg/kg; n = 10). Induction of anesthesia was done with propofol, and maintenance of anesthesia was done with isoflurane. Intraoperative heart rate, arterial blood pressure, respiratory rate, end-tidal isoflurane concentration and frequency of rescue analgesia (fentanyl 2.5 µg/kg) were compared between groups. Postoperative analgesia was assessed using the UNESP-Botucatu Multidimensional Composite Pain Scale, and perioperative serum glucose, cortisol concentrations and postoperative rescue analgesia were evaluated. RESULTS: Intraoperative rescue analgesia was required in 76.5% of cats at some time during surgery, and 27% of cats required postoperative rescue analgesia up to 6 h after extubation. There were no significant differences between groups with respect to intraoperative and postoperative rescue analgesia, pain scale scores and end-tidal isoflurane concentrations. In the immediate postoperative period, after extubation, most of the patients presented with hypothermia; however, 1-6 h postoperatively, hyperthermia was observed in most of the patients, and was most common in the tramadol group. CONCLUSIONS AND CLINICAL RELEVANCE: Under the conditions of this study, methadone, morphine and tramadol produced satisfactory postoperative analgesia in most of the cats undergoing ovariohysterectomy, and the effects lasted up to 6 h postoperatively. Intraoperative analgesia was not sufficient in most cases. Significant cardiovascular or respiratory effects contraindicating the use of these drugs were not found. Postanesthetic hyperthermia occurred with all opioids studied and was more frequent in the tramadol group.

Methadone Requires the Co-Activation of µ-Opioid and Toll-Like-4 Receptors to Produce Extracellular DNA Traps in Bone-Marrow-Derived Mast Cells.

Methadone is an effective and long-lasting analgesic drug that is also used in medication-assisted treatment for people with opioid use disorders. Although there is evidence that methadone activates µ-opioid and Toll-like-4 receptors (TLR-4s), its effects on distinct immune cells, including mast cells (MCs), are not well characterized. MCs express µ-opioid and Toll-like receptors (TLRs) and constitute an important cell lineage involved in allergy and effective innate immunity responses. In the present study, murine bone-marrow-derived mast cells (BMMCs) were treated with methadone to evaluate cell viability by flow cytometry, cell morphology with immunofluorescence and scanning electron microscopy, reactive oxygen species (ROS) production, and intracellular calcium concentration ([Ca2+]i) increase. We found that exposure of BMMCs to 0.5 mM or 1 mM methadone rapidly induced cell death by forming extracellular DNA traps (ETosis). Methadone-induced cell death depended on ROS formation and [Ca2+]i. Using pharmacological approaches and TLR4-defective BMMC cultures, we found that µ-opioid receptors were necessary for both methadone-induced ROS production and intracellular calcium increase. Remarkably, TLR4 receptors were also involved in methadone-induced ROS production as it did not occur in BMMCs obtained from TLR4-deficient mice. Finally, confocal microscopy images showed a significant co-localization of µ-opioid and TLR4 receptors that increased after methadone treatment. Our results suggest that methadone produces MCETosis by a mechanism requiring a novel crosstalk pathway between µ-opioid and TLR4 receptors.

The impact of cannabis on non-medical opioid use among individuals receiving pharmacotherapies for opioid use disorder: a systematic review and meta-analysis of longitudinal studies.

Background: The relationship between cannabis use and the risk of returning to using opioids non-medically during treatment for opioid use disorder (OUD) remains unclear.Objective: We sought to quantify the impact of cannabis use on the risk of non-medical opioid use among people receiving pharmacotherapies for OUD.Methods: A comprehensive search was performed using multiple databases from March 1 to April 5 of 2023. Eligible studies longitudinally assessed the association between cannabis use and non-medical opioid use among people with OUD receiving treatment with buprenorphine, methadone, or naltrexone. We utilized a random-effects model employing the restricted maximum likelihood method. A sensitivity analysis was conducted to understand potential differences between each OUD treatment modality.Results: A total of 10 studies were included in the final meta-analysis. There were 8,367 participants (38% female). The average follow-up time across these studies was 9.7 months (SD = 3.77), ranging from 4 to 15 months. The pharmacotherapies involved were methadone (76.3%) buprenorphine (21.3%), and naltrexone (2.4%). The pooled odds ratio did not indicate that cannabis use significantly influenced non-medical opioid use (OR: 1.00, 95% CI: 0.97-1.04, p = .98). There is evidence of moderate heterogeneity and publication bias.Conclusion: There was no significant association between cannabis use and non-medical opioid use among patients receiving pharmacotherapies for OUD. These findings neither confirm concerns about cannabis increasing non-medical opioid use during MOUD, nor do they endorse its efficacy in decreasing non-medical opioid use with MOUD. This indicates a need for individualized approaches for cannabis use and challenges the requirement of cannabis abstinence to maintain OUD pharmacotherapies.

Influence of CYP2B6 Genotype on Methadone Dosage in Patients from the Methadone Maintenance Treatment (MMT) Program in Pereira, Colombia.

Methadone treatment reduces the use of heroin and withdrawal symptoms; however, methadone is an expensive medication with a narrow safety margin. We compared the retention rates, persistence of heroin use, and quality of life of a group of patients undergoing conventional Methadone Maintenance Treatment (MMT) with a group for whom the CYP2B6 516G>T polymorphism was used in addition to the MMT to calculate the required methadone dose. Over 12 weeks, the retention rate, heroin usage, and quality of life of patients under conventional treatment (n = 34) were compared with those of patients for whom we used genetic markers to calculate methadone dosage (n = 38). At the end of the study, 26.4% of patients abandoned the program, and neither demographic nor clinical variables were associated with treatment adherence. Of the remaining patients, 16% of the control group and 8% of patients in the pharmacogenetic group reported heroin use, while both groups showed a 64% reduction in the use of cocaine/crack (no significant differences between the groups were found). Starting in the second week, the methadone dosage was lower among the patients for whom methadone was prescribed based on genotype. Although there were six individuals in the control group and three in the pharmacogenetic group with QTc intervals > 450 ms (a threshold that is considered dangerous), we did not find a relationship between the QTc interval and methadone dosage. There were no differences in the perception of quality of life between the two groups. The results of this pilot study suggest that concerning methadone therapy, the CYP2B6 genotype contributes to reduced effective doses and treatment costs.

Structural violence and the need for compassionate use of methadone in Mexico.

BACKGROUND: Epidemiological data from Mexico have documented an increase in heroin use in the last decade. However, there is no comprehensive care strategy for heroin users, especially those who have been accused of a crime. The objective of this study was to describe the heroin and methadone use of intravenous heroin users of both sexes who have been in jail, to offer evidence for the formulation of health policy. METHODS: This study used an ethnographic approach, with open-ended interviews carried out from 2014 to the present. Heroin users of both sexes attending a private methadone clinic in Mexico City were invited to participate. The sample was non-probabilistic. All interviews were audiotaped and transcribed, and narratives were analyzed using thematic analysis. RESULTS: Participants in this study were 33 users of heroin, two of them women, who had been in prison. They ranged in age from 33 to 62 years, had used heroin for a period of 13-30 years, and were from three states: Michoacan, Oaxaca, and Mexico City. Three principal categories of analysis were structured: 1. Pilgrimage for help (dynamics of the drama of suffering, pain, and time through health care spaces); 2) methadone use as self-care; and 3) accessibility to methadone treatment. The impossibility of access to methadone treatment is a condition which motivates users in their journey. The dynamics of methadone use are interpreted as a form of self-care and care to avoid substance use. Reducing the psychological, physical, and harmful effects of the substance allows them to perform daily activities. The inability to access treatment leads to a significant effect on users who experience structural violence. CONCLUSION: Compassionate methadone treatment and holistic attention should be considered as a way to meet patients' needs and mitigate their suffering, based on public health policy that allows for human rights-based care.

Use of methadone as an alternative to morphine for chronic pain management: a noninferiority retrospective observational study.

INTRODUCTION: Chronic pain causes disability and is prevalent in the general population. Opioids are a part of a multimodal strategy for pain management. Methadone, a cheap and long-acting synthetic opioid, may represent an option for those who have limited access to the aforementioned class of analgesics. We aimed to provide a real-world evidence for the analgesic use of methadone, compared with morphine. METHODS: We conducted a noninferiority, retrospective observational single center study of patients with chronic pain, managed with either methadone or morphine at an outpatient specialized clinic. We extracted data from the electronic health records of patients who underwent an active treatment between August 2012 and January 2020 and were examined for at least 2 consecutive medical visits, after the administration of one of the aforementioned drugs. Data were analyzed using a generalized additive model with random-effects mixed linear method to account for the individual-related, time-related, and drug-related variations. The numeric verbal scale (0-10) was used to assess the pain severity. RESULTS: From the database of 3373 patients, we included 262 patients (175 methadone and 87 morphine). In an unadjusted analysis, methadone was superior to morphine, and the mean worst pain was 0.86 points lower (95% confidence interval, -1.29 to -0.43). Moreover, methadone was superior to morphine in the adjusted analysis, with the worst pain mean being 1.24 points lower. This provided evidence for the noninferiority of methadone than morphine. CONCLUSION: Methadone was superior to morphine in a 20% noninferiority margin for reducing worst pain.

Antinociceptive synergism upon the joint use of methadone and Phα1ß in a model of cancer-related pain in C57BL/6J mice.

Opioids are the first-line treatment for cancer pain. Incomplete pain relief and the high rate of adverse effects of these compounds bring a need to combine them with other drugs acting on different targets. AIMS: We here evaluate the antinociceptive interaction and adverse events of methadone combined with recombinant Phα1ß, an analgesic toxin from Phoneutria nigriventer. MAIN METHODS: Melanoma was produced by intraplantar inoculation of B16-F10 cells into the right paw. von Frey filaments measured the paw-withdrawal threshold after administration of methadone, Phα1ß, and their combination. The degree of interaction was evaluated using isobolographic analysis. Spontaneous performance and forced motor performance were assessed with the open-field and rotarod tests, respectively. Intestinal function was evaluated by the distance traveled by charcoal and opioid tolerance was induced by daily morphine injections. KEY FINDINGS: Co-administration of Phα1ß with methadone synergistically reverses the melanoma-induced mechanical hypersensitivity. No motor alterations were observed but mild alterations on intestinal function after treatment with the combination that was also capable of restoring morphine analgesia in the tail-flick test after an opioid-induced tolerance. SIGNIFICANCE: Combinatorial treatment with Phα1ß and methadone produces synergistic analgesic potentiation with potential implications to pain treatment even under opioid tolerance conditions.

Efficacy of methadone for the management of postoperative pain in laparoscopic cholecystectomy: A randomized clinical trial. / Eficacia de la metadona para el tratamiento del dolor postoperatorio en colecistectomía laparoscópica: ensayo clínico aleatorizado.

BACKGROUND: Postoperative pain management contributes to reducing postoperative morbidity and unscheduled readmission. Compared to other opioids that manage postoperative pain like morphine, few randomized trials have tested the efficacy of intraoperatively administered methadone to provide evidence for its regular use or be included in clinical guidelines. METHODS: We conducted a randomized clinical trial comparing the use of intraoperative methadone to assess its impact on postoperative pain. Eighty-six patients undergoing elective laparoscopic cholecystectomy were allocated to receive either methadone (0.08 mg/kg) or morphine (0.08 mg/kg). RESULTS: Individuals who received methadone required less rescue morphine in the Post Anesthesia Care Unit for postoperative pain than those who received morphine (p = 0.0078). The patients from the methadone group reported less pain at 5 and 15 minutes and 12 and 24 hours following Post Anesthesia Care Unit discharge, exhibiting fewer episodes of nausea. Time to eye-opening was equivalent between the two groups. CONCLUSION: Intraoperative use of methadone resulted in better management of postoperative pain, supporting its use as part of a multimodal pain management strategy for laparoscopic cholecystectomy under remifentanil-based anesthesia.

INTRODUCCIÓN: El manejo del dolor postoperatorio contribuye a reducir la morbilidad postoperatoria y los reingresos no programados. Pocos ensayos clínicos aleatorizados han evaluado la eficacia de la administración intraoperatoria de metadona en comparación con otros opioides como morfina, para el tratamiento del dolor postoperatorio, como para proporcionar evidencia de su uso regular o incluirse en guías clínicas. MÉTODOS: Realizamos un ensayo clínico aleatorizado comparando el uso de metadona intraoperatoria para evaluar su impacto sobre el dolor postoperatorio. Ochenta y seis pacientes sometidos a colecistectomía laparoscópica electiva fueron asignados para recibir metadona (0,08 mg/kg) o morfina (0,08 mg/kg). RESULTADOS: El grupo de pacientes que recibió metadona requirió menos morfina de rescate en la unidad de cuidados post-anestésicos para el manejo del dolor posoperatorio, en comparación con el grupo morfina (p = 0,0078). Los pacientes del grupo metadona reportaron menos dolor a los 5 y 15 minutos, y a las 12 y 24 horas postoperatorias, además de presentar menos episodios de náuseas. El tiempo de despertar entre ambos grupos fue equivalente. CONCLUSIÓN: El uso intraoperatorio de metadona es superior a morfina en el manejo del dolor postoperatorio, apoyando su uso como parte de la estrategia de manejo multimodal del dolor para colecistectomía laparoscópica bajo anestesia total endovenosa con remifentanilo.

First-line methadone for cancer pain: titration time analysis.

BACKGROUND: Methadone is a low-cost, strong opioid that is increasingly used as a first-line treatment for pain in palliative care (PC). Its long and unpredictable half-life and slow elimination phase can make titration challenging. Evidence for titration modalities is scarce. OBJECTIVE: To describe the titration phase of the treatment with low-dose first-line methadone and the use of methadone for breakthrough pain. METHODS: Prospective study with strong opioid-naïve patients with moderate to severe cancer pain followed at a tertiary PC unit in Argentina. Starting methadone dose was 2.5-5 mg/day every 8, 12, or 24 h. Titration allowed daily dose increases from day 1, and prescription of oral methadone 2.5 mg every 2 h with a maximum of 3 rescue doses/day for breakthrough pain. Pain control, methadone stabilization dose, and adverse effects, among other variables, were daily assessed over the first 7 days (T0-T7). RESULTS: Sixty-two patients were included. Initial median (IQR) methadone dose was 5 (2.5) mg/day. Pain intensity decreased from a median (IQR) of 8 (2.3) at T0 to 4 (2.3) at T1 and remained ≤ 4 until T7 (all p < 0.0001 compared to T0). Similar results were obtained through the categorical and tolerability scales for pain. Fifty patients (81%) reached pain control, 66% in the first 48 h. Methadone daily doses at T2 and T7 were higher than that at T0: 7.5 (3) and 6.7 (5.5) versus 5 (2.5), respectively (all p < 0.05). The opioid escalation index at T7 was 1.7%. The median (IQR) number of rescues, stabilization dose, and time for stabilization was 0 (1), 5(4.5) mg, and 3(2) days, respectively. Two patients were discontinued due to delirium. All other side effects were mild. CONCLUSIONS: First-line, low-dose methadone using rescue methadone resulted in a pronounced and rapid decrease in pain, with minimal need for titration and for breakthrough doses, and no evidence of accumulation or sedation by the end of the week.

Development, Validation, and Reliability of a Sedation Scale in Horses (EquiSed).

The lack of standardization of sedation scales in horses limits the reproducibility between different studies. This prospective, randomized, blinded, horizontal and controlled trial aimed to validate a scale for sedation in horses (EquiSed). Seven horses were treated with intravenous detomidine in low/high doses alone (DL 2.5 µg/kg + 6.25 µg/kg/h; DH 5 µg/kg +12.5 µg/kg/h) or associated with methadone (DLM and DHM, 0.2 mg/kg + 0.05 mg/kg/h) and with low (ACPL 0.02 mg/kg) or high (ACPH 0.09 mg/kg) doses of acepromazine alone. Horses were filmed at (i) baseline (ii) peak, (iii) intermediate, and (iv) end of sedation immediately before auditory, visual and pressure stimuli were applied and postural instability evaluated for another study. Videos were randomized and blindly evaluated by four evaluators in two phases with 1-month interval. Intra- and interobserver reliability of the sum of EquiSed (Intraclass correlation coefficient) ranged between 0.84-0.94 and 0.45-0.88, respectively. The criterion validity was endorsed by the high Spearman correlation between the EquiSed and visual analog (0.77), numerical rating (0.76), and simple descriptive scales (0.70), and average correlation with head height above the ground (HHAG) (-0.52). The Friedman test confirmed the EquiSed responsiveness over time. The principal component analysis showed that all items of the scale had a load factor ≥ 0.50. The item-total Spearman correlation for all items ranged from 0.3 to 0.5, and the internal consistency was good (Cronbach's α = 0.73). The area under the curve of EquiSed HHAG as a predictive diagnostic measure was 0.88. The sensitivity of the EquiSed calculated according to the cut-off point (score 7 of the sum of the EquiSed) determined by the receiver operating characteristic curve, was 96% and specificity was 83%. EquiSed has good intra- and interobserver reliabilities and is valid to evaluate tranquilization and sedation in horses.

Opioids in COVID-19: Two Sides of a Coin.

Introduction: The treatment of most severe COVID-19 patients included the large-scale use of sedatives and analgesics-possibly in higher doses than usual-which was reported in the literature. The use of drugs that decrease mortality is necessary and opioids are important agents in procedures such as orotracheal intubation. However, these drugs seem to have been overestimated in the COVID-19 pandemic. We performed a review of the PubMed-Medline database to evaluate the use of opioids during this period. The following descriptors were used to enhance the search for papers: "Opioids", "COVID-19," "COVID-19 pandemic," "SARS-CoV-2," "Opioid use disorder," "Opioid dependence" and the names of the drugs used. We also evaluated the distribution of COVID-19 patients in Brazil and the applicability of opioids in our country during the COVID-19 pandemic. Results: Several positive points were found in the use of opioids in the COVID-19 pandemic, for instance, they can be used for analgesia in orotracheal intubation, for chronic pain management, and as coadjutant in the management of acute intensification of pain. However, high doses of opioids might exacerbate the respiratory depression found in COVID-19 patients, their chronic use can trigger opioid tolerance and the higher doses used during the pandemic might result in greater adverse effects. Unfortunately, the pandemic also affected individuals with opioid use disorder, not only those individuals are at higher risk of mortality, hospitalization and need for ventilatory support, but measures taken to decrease the SARS-CoV-2 spread such as social isolation, might negatively affect the treatment for opioid use disorder. In Brazil, only morphine, remifentanil and fentanyl are available in the basic health care system for the treatment of COVID-19 patients. Out of the 5,273,598 opioid units used in this period all over the country, morphine, fentanyl, and remifentanil, accounted for, respectively, 559,270 (10.6%), 4,624,328 (87.6%), and 90,000 (1.8%) units. Many Brazilian regions with high number of confirmed cases of COVID-19 had few units of opioids available, as the Southeast region, with a 0.23 units of opioids per confirmed COVID-19 case, and the South region, with 0.05 units. In the COVID-19 pandemic scenario, positive points related to opioids were mainly the occurrence of analgesia, to facilitate intubation and their use as coadjutants in the management of acute intensification of pain, whereas the negative points were indiscriminate use, the presence of human immunosuppressor response and increased adverse effects due to higher doses of the drug. Conclusion: The importance of rational and individualized use of analgesic hypnotics and sedative anesthetics should be considered at all times, especially in situations of high demand such as the COVID-19 pandemic.

Intra-operative methadone effect on quality of recovery compared with morphine following laparoscopic gastroplasty: a randomised controlled trial.

The effect of intra-operative intravenous methadone on quality of postoperative recovery was compared with morphine after laparoscopic gastroplasty. We included 137 adult patients with a body mass index > 35 kg.m-2 who underwent bariatric surgery. Patients were allocated at random to receive either intra-operative methadone (n = 69) or morphine (n = 68). All patients received the same postoperative care and analgesia. The primary outcome of postoperative quality of recovery was assessed using the Quality of Recovery-40 questionnaire total score 24 h after surgery. Secondary outcomes were assessed in the post-anaesthesia care unit the night of the day of surgery (T1), in the morning after surgery (T2); and at night on the day following surgery (T3). The median (IQR [range]) total Quality of Recovery-40 questionnaire score of 194 (190-197 [165-200]) was higher (p < 0.0001) in the methadone group compared with the score of 181 (174-185.5 [121-200]) in the morphine group. In the post-anaesthesia care unit, the pain burden; incidence of nausea and vomiting; rescue morphine dose; and time to discharge, were significantly lower in the methadone group. On the ward, the methadone group had a lower: incidence of rescue morphine requests at T1 (5.8 vs. 54.4%, p < 0.0001) and T2 (0 vs. 20.1%, p < 0.0001); and incidence of nausea (21.7 vs. 41.2%, p = 0.014), compared with the morphine group. We conclude that intra-operative intravenous methadone improved quality of recovery in patients who underwent laparoscopic gastroplasty, compared with intra-operative morphine. Methadone also reduced postoperative pain, postoperative opioid consumption and the incidence of opioid-related adverse events.

The need for opioid in the postoperative analgesia of dogs undergoing hemilaminectomy due to intervertebral disc extrusion / A necessidade de opioide na analgesia pós-operatória de cães submetidos à hemilaminectomia devido à extrusão do disco intervertebral

The aim of this study was to evaluate the postoperative analgesic effect of protocols with and without the opioid methadone in dogs with intervertebral disc extrusion undergoing decompressive surgery. Sixteen paraplegic dogs with preserved nociception underwent hemilaminectomy/disc fenestration and were randomly assigned to two groups. The analgesic protocol consisted of methadone, meloxicam and dipyrone in Group I (G1), and meloxicam and dipyrone in Group II (G2). The animals were blindly assessed by two observers, using the visual analogue scale (VAS) and the short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Assessments occurred every 2 hours during first 24 hours post-surgery, and every 4 hours afterwards. There was no statistical difference among groups regarding pain scores or analgesic rescues. Both analgesic protocols provided analgesia in the initial 48 hours postoperatively, demonstrating that opioids are not necessary in the postoperative period of dogs undergoing hemilaminectomy and disc fenestration.(AU)

O objetivo deste estudo foi avaliar a analgesia pós-operatória de protocolos com e sem o opioide metadona em cães com extrusão de disco intervertebral submetidos à descompressão cirúrgica. Dezesseis cães paraplégicos com presença de nocicepção foram submetidos à hemilaminectomia/fenestração de disco e distribuídos aleatoriamente em dois grupos. No Grupo I (G1), o protocolo analgésico consistiu em metadona, meloxicam e dipirona e, no Grupo II (G2), por meloxicam e dipirona. Os pacientes foram avaliados de maneira cega por dois avaliadores, com base na escala visual analógica (EVA) e na escala simplificada composta de dor de Glasgow (CMPS-SF). As avaliações ocorreram a cada 2 horas durante as primeiras 24 horas de pós-operatório e, por mais 24 horas, a cada 4 horas. Não houve diferença estatística entre os grupos avaliados em relação à escores de dor e nem a necessidade de resgate analgésico. Ambos os protocolos promoveram analgesia nas 48 horas iniciais de pós-operatório, demonstrando não haver a necessidade do uso de opioide em cães submetidos à hemilaminectomia e fenestração de disco.(AU)

The need for opioid in the postoperative analgesia of dogs undergoing hemilaminectomy due to intervertebral disc extrusion

ABSTRACT: The aim of this study was to evaluate the postoperative analgesic effect of protocols with and without the opioid methadone in dogs with intervertebral disc extrusion undergoing decompressive surgery. Sixteen paraplegic dogs with preserved nociception underwent hemilaminectomy/disc fenestration and were randomly assigned to two groups. The analgesic protocol consisted of methadone, meloxicam and dipyrone in Group I (G1), and meloxicam and dipyrone in Group II (G2). The animals were blindly assessed by two observers, using the visual analogue scale (VAS) and the short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Assessments occurred every 2 hours during first 24 hours post-surgery, and every 4 hours afterwards. There was no statistical difference among groups regarding pain scores or analgesic rescues. Both analgesic protocols provided analgesia in the initial 48 hours postoperatively, demonstrating that opioids are not necessary in the postoperative period of dogs undergoing hemilaminectomy and disc fenestration.

RESUMO: O objetivo deste estudo foi avaliar a analgesia pós-operatória de protocolos com e sem o opioide metadona em cães com extrusão de disco intervertebral submetidos à descompressão cirúrgica. Dezesseis cães paraplégicos com presença de nocicepção foram submetidos à hemilaminectomia/fenestração de disco e distribuídos aleatoriamente em dois grupos. No Grupo I (G1), o protocolo analgésico consistiu em metadona, meloxicam e dipirona e, no Grupo II (G2), por meloxicam e dipirona. Os pacientes foram avaliados de maneira cega por dois avaliadores, com base na escala visual analógica (EVA) e na escala simplificada composta de dor de Glasgow (CMPS-SF). As avaliações ocorreram a cada 2 horas durante as primeiras 24 horas de pós-operatório e, por mais 24 horas, a cada 4 horas. Não houve diferença estatística entre os grupos avaliados em relação à escores de dor e nem a necessidade de resgate analgésico. Ambos os protocolos promoveram analgesia nas 48 horas iniciais de pós-operatório, demonstrando não haver a necessidade do uso de opioide em cães submetidos à hemilaminectomia e fenestração de disco.

The need for opioid in the postoperative analgesia of dogs undergoing hemilaminectomy due to intervertebral disc extrusion / A necessidade de opioide na analgesia pós-operatória de cães submetidos à hemilaminectomia devido à extrusão do disco intervertebral

The aim of this study was to evaluate the postoperative analgesic effect of protocols with and without the opioid methadone in dogs with intervertebral disc extrusion undergoing decompressive surgery. Sixteen paraplegic dogs with preserved nociception underwent hemilaminectomy/disc fenestration and were randomly assigned to two groups. The analgesic protocol consisted of methadone, meloxicam and dipyrone in Group I (G1), and meloxicam and dipyrone in Group II (G2). The animals were blindly assessed by two observers, using the visual analogue scale (VAS) and the short-form Glasgow Composite Measure Pain Scale (CMPS-SF). Assessments occurred every 2 hours during first 24 hours post-surgery, and every 4 hours afterwards. There was no statistical difference among groups regarding pain scores or analgesic rescues. Both analgesic protocols provided analgesia in the initial 48 hours postoperatively, demonstrating that opioids are not necessary in the postoperative period of dogs undergoing hemilaminectomy and disc fenestration.(AU)

O objetivo deste estudo foi avaliar a analgesia pós-operatória de protocolos com e sem o opioide metadona em cães com extrusão de disco intervertebral submetidos à descompressão cirúrgica. Dezesseis cães paraplégicos com presença de nocicepção foram submetidos à hemilaminectomia/fenestração de disco e distribuídos aleatoriamente em dois grupos. No Grupo I (G1), o protocolo analgésico consistiu em metadona, meloxicam e dipirona e, no Grupo II (G2), por meloxicam e dipirona. Os pacientes foram avaliados de maneira cega por dois avaliadores, com base na escala visual analógica (EVA) e na escala simplificada composta de dor de Glasgow (CMPS-SF). As avaliações ocorreram a cada 2 horas durante as primeiras 24 horas de pós-operatório e, por mais 24 horas, a cada 4 horas. Não houve diferença estatística entre os grupos avaliados em relação à escores de dor e nem a necessidade de resgate analgésico. Ambos os protocolos promoveram analgesia nas 48 horas iniciais de pós-operatório, demonstrando não haver a necessidade do uso de opioide em cães submetidos à hemilaminectomia e fenestração de disco.(AU)

Revisión de metadona intraoperatoria para el manejo de dolor posquirúrgico / Intraoperative methadone for the management of postsurgical pain a review

Pain management associated with surgery is a constant concern of the health team as well as the patient. Multiple proposals for analgesia have been made in the perioperative context. The use of opioids with rapid effect and easy titration in the intraoperative period are currently frequent; to then perform a postoperative analgesic control with drugs with a longer half-life, usually achieving adequate pain management. However, sometimes the standard analgesic scheme is not enough. The problems associated with this situation have led to the need for high doses of opioids in the postoperative period, with the requirement for monitoring, health personnel, and the adverse effects that these involve. Methadone is a long-acting, rapid-onset opioid, the latter secondary to its long elimination half-life. It is presumed that these characteristics have led patients to report adequate pain management, which has been related to a decrease in the need and dose of rescue opioids, in addition to delaying the requirement of these if necessary during the postoperative. These properties allow methadone to be a potential solution to perioperative pain management.

El manejo del dolor asociado a la cirugía es una preocupación constante del equipo de salud al igual que del paciente. Se han planteado múltiples propuestas de analgesia en el contexto perioperatorio, siendo actualmente frecuente el uso de opioides de rápido efecto y fácil titulación en el intraoperatorio; para luego realizar un control analgésico postoperatorio con fármacos de mayor vida media, logrando habitualmente un manejo adecuado del dolor. Sin embargo, a veces el esquema analgésico estándar no es suficiente. La problemática asociada a esta situación ha llevado a la necesidad de altas dosis de opioides en el posoperatorio, con el requerimiento de monitorización, personal de salud y efectos adversos que estos involucran. La metadona es un opioide de inicio de acción rápido y larga duración, este último secundario a su vida media de eliminación prolongada. Se presume que estas características han logrado que los pacientes reporten un adecuado manejo de su dolor, lo que se ha relacionado a una disminución en la necesidad y dosis de opioides de rescate, además de retrasar el requerimiento de éstos en el caso de ser necesarios durante el postoperatorio. Estas propiedades permiten que la metadona pueda ser una potencial solución al manejo del dolor perioperatorio.

The role of drug treatment and recovery services: an opportunity to address injection initiation assistance in Tijuana, Mexico.

BACKGROUND: In the U.S. and Canada, people who inject drugs' (PWID) enrollment in medication-assisted treatment (MAT) has been associated with a reduced likelihood that they will assist others in injection initiation events. We aimed to qualitatively explore PWID's experiences with MAT and other drug treatment and related recovery services in Tijuana Mexico, a resource-limited setting disproportionately impacted by injection drug use. METHODS: PReventing Injecting by Modifying Existing Responses (PRIMER) seeks to assess socio-structural factors associated with PWID provision of injection initiation assistance. This analysis drew on qualitative data from Proyecto El Cuete (ECIV), a Tijuana-based PRIMER-linked cohort study. In-depth qualitative interviews were conducted with a subset of study participants to further explore experiences with MAT and other drug treatment services. Qualitative thematic analyses examined experiences with these services, including MAT enrollment, and related experiences with injection initiation assistance provision. RESULTS: At PRIMER baseline, 607(81.1%) out of 748 participants reported recent daily IDU, 41(5.5%) reported recent injection initiation assistance, 92(12.3%) reported any recent drug treatment or recovery service access, and 21(2.8%) reported recent MAT enrollment (i.e., methadone). Qualitative analysis (n = 21; female = 8) revealed that, overall, abstinence-based recovery services did not meet participants' recovery goals, with substance use-related social connections in these contexts potentially shaping injection initiation assistance. Themes also highlighted individual-level (i.e., ambivalence and MAT-related stigma) and structural-level (i.e., cost and availability) barriers to MAT enrollment. CONCLUSION: Tijuana's abstinence-based drug treatment and recovery services were viewed as unable to meet participants' recovery-related goals, which could be limiting the potential benefits of these services. Drug treatment and recovery services, including MAT, need to be modified to improve accessibility and benefits, like preventing transitions into drug injecting, for PWID.

Cost-effectiveness analysis of a large jail-based methadone maintenance treatment continuation program in New Mexico.

The U.S. has the second-highest incarceration rate in the world and spends more than $80 billion annually to house inmates. The clinical research literature suggests that methadone maintenance treatment (MMT) is an effective method to treat opioid use disorders (OUD) and that jails are a potentially valuable environment to implement MMT. Currently, jail-based MMT is rarely implemented in practice, due in part to resource limitations and other economic considerations. The primary goal of this study was to perform a cost-effectiveness analysis (CEA) of jail-based MMT using data from a unique MMT continuation program located in a large urban jail in New Mexico. Recidivism data were collected for a three-year period both before and after incarceration, and quasi-control groups were constructed from both substance-using and general populations within the jail. Base models show that inmates enrolled in jail-based MMT exhibited significantly fewer days of incarceration due to recidivism (29.33) than a group of inmates with OUDs who did not receive MMT. Economic estimates indicate that it cost significantly less ($23.49) to reduce an incarcerated day using jail-based MMT than incarceration per se ($116.49). To mitigate potential sample selection bias, we used both propensity-score-matching and difference-in-differences estimators, which provided comparable estimates when using the OUD non-MMT comparison group. Difference-in-differences models find that, on average, MMT reduced recidivism by 24.80 days and it cost $27.78 to reduce an incarcerated day using jail-based MMT. Assuming a willingness to pay threshold of the break-even cost of reducing one incarcerated day, we estimate a 93.3% probability that this MMT program is cost-effective. Results were not as strong or consistent when using other comparison groups (e.g., alcohol-detoxified and general-population inmates). Overall, results suggest that it costs substantially less to provide jail-based MMT than incarceration alone. Jail administrators and policymakers should consider incorporating MMT in other jail systems and settings.