Low dose of morphine to relieve dyspnea in acute respiratory failure: the OpiDys double-blind randomized controlled trial.

BACKGROUND: Morphine relieves dyspnea in various clinical circumstances. Whether or not this applies to patients admitted to intensive care units (ICUs) for acute respiratory failure (ARF) is unknown. We evaluated the efficacy and safety of low-dose morphine on dyspnea in patients admitted to the ICU for ARF. METHODS: In this single-center, double-blind, phase 2, randomized, controlled trial, we assigned non-intubated adults admitted to the ICU for ARF with severe dyspnea, defined by a visual analog scale for dyspnea (dyspnea-VAS) from zero (no dyspnea) to 100 mm (worst imaginable dyspnea) ≥40 mm, to receive a low dose of Morphine Hydrochloride (intravenous titration followed by subcutaneous relay) or Placebo. All patients received standard therapy, including etiological treatment and non-invasive respiratory support. RESULTS: Twenty-two patients were randomized, 11 in each group. The average dyspnea (median [interquartile range]) over 24 hours did not significantly differ between the two groups (40 [25 - 43] mm in the Morphine group vs. 40 [36 - 49] mm in the Placebo group, p=0.411). Dyspnea-VAS was lower in the Morphine group than in the Placebo group at the end of intravenous titration (30 [11 - 30] vs. 35 [30 - 44], p=0.044) and four hours later (18 [10 - 29] vs. 50 [30 - 60], p=0.043). The cumulative probability of intubation was higher in the Morphine group than in the Placebo group (p=0.046) CONCLUSION: In this phase 2 pilot trial, morphine did not improve 24-hour average dyspnea in adult patients with ARF, even though it had a statistically significant immediate effect. Of concern, Morphine use was associated with a higher intubation rate. TRIAL REGISTRATION: The protocol was declared on the ClinicalTrial.gov database (no. NCT04358133) and was published in September 2022.

KCTD proteins regulate morphine dependence via heterologous sensitization of adenylyl cyclase 1 in mice.

Heterologous sensitization of adenylyl cyclase (AC) results in elevated cAMP signaling transduction that contributes to drug dependence. Inhibiting cullin3-RING ligases by blocking the neddylation of cullin3 abolishes heterologous sensitization, however, the modulating mechanism remains uncharted. Here, we report an essential role of the potassium channel tetramerization domain (KCTD) protein 2, 5, and 17, especially the dominant isoform KCTD5 in regulating heterologous sensitization of AC1 and morphine dependence via working with cullin3 and the cullin-associated and neddylation-dissociated 1 (CAND1) protein. In cellular models, we observed enhanced association of KCTD5 with Gß and cullin3, along with elevated dissociation of Gß from AC1 as well as of CAND1 from cullin3 in heterologous sensitization of AC1. Given binding of CAND1 inhibits the neddylation of cullin3, we further elucidated that the enhanced interaction of KCTD5 with both Gß and cullin3 promoted the dissociation of CAND1 from cullin3, attenuated the inhibitory effect of CAND1 on cullin3 neddylation, ultimately resulted in heterologous sensitization of AC1. The paraventricular thalamic nucleus (PVT) plays an important role in mediating morphine dependence. Through pharmacological and biochemical approaches, we then demonstrated that KCTD5/cullin3 regulates morphine dependence via modulating heterologous sensitization of AC, likely AC1 in PVT in mice. In summary, the present study revealed the underlying mechanism of heterologous sensitization of AC1 mediated by cullin3 and discovered the role of KCTD proteins in regulating morphine dependence in mice.

A New Application for Cenicriviroc, a Dual CCR2/CCR5 Antagonist, in the Treatment of Painful Diabetic Neuropathy in a Mouse Model.

The ligands of chemokine receptors 2 and 5 (CCR2 and CCR5, respectively) are associated with the pathomechanism of neuropathic pain development, but their role in painful diabetic neuropathy remains unclear. Therefore, the aim of our study was to examine the function of these factors in the hypersensitivity accompanying diabetes. Additionally, we analyzed the analgesic effect of cenicriviroc (CVC), a dual CCR2/CCR5 antagonist, and its influence on the effectiveness of morphine. An increasing number of experimental studies have shown that targeting more than one molecular target is advantageous compared with the coadministration of individual pharmacophores in terms of their analgesic effect. The advantage of using bifunctional compounds is that they gain simultaneous access to two receptors at the same dose, positively affecting their pharmacokinetics and pharmacodynamics and consequently leading to improved analgesia. Experiments were performed on male and female Swiss albino mice with a streptozotocin (STZ, 200 mg/kg, i.p.) model of diabetic neuropathy. We found that the blood glucose level increased, and the mechanical and thermal hypersensitivity developed on the 7th day after STZ administration. In male mice, we observed increased mRNA levels of Ccl2, Ccl5, and Ccl7, while in female mice, we observed additional increases in Ccl8 and Ccl12 levels. We have demonstrated for the first time that a single administration of cenicriviroc relieves pain to a similar extent in male and female mice. Moreover, repeated coadministration of cenicriviroc with morphine delays the development of opioid tolerance, while the best and longest-lasting analgesic effect is achieved by repeated administration of cenicriviroc alone, which reduces pain hypersensitivity in STZ-exposed mice, and unlike morphine, no tolerance to the analgesic effects of CVC is observed until Day 15 of treatment. Based on these results, we suggest that targeting CCR2 and CCR5 with CVC is a potent therapeutic option for novel pain treatments in diabetic neuropathy patients.

Discovery of BI-9508, a Brain-Penetrant GPR88-Receptor-Agonist Tool Compound for In Vivo Mouse Studies.

Decreased activity and expression of the G-protein coupled receptor GPR88 is linked to many behavior-linked neurological disorders. Published preclinical GPR88 allosteric agonists all have in vivo pharmacokinetic properties that preclude their progression to the clinic, including high lipophilicity and poor brain penetration. Here, we describe our attempts to improve GPR88 agonists' drug-like properties and our analysis of the trade-offs required to successfully target GPR88's allosteric pocket. We discovered two new GPR88 agonists: One that reduced morphine-induced locomotor activity in a murine proof-of-concept study, and the atropoisomeric BI-9508, which is a brain penetrant and has improved pharmacokinetic properties and dosing that recommend it for future in vivo studies in rodents. BI-9508 still suffers from high lipophilicity, and research on this series was halted. Because of its utility as a tool compound, we now offer researchers access to BI-9508 and a negative control free of charge via Boehringer Ingelheim's open innovation portal opnMe.com.

Anterior quadratus lumborum block provided superior pain control and reduced opioid consumption in kidney transplantation: A randomized controlled trial.

BACKGROUND: The research aimed to assess the effectiveness of inside-out anterior quadratus lumborum (QL3) block and local wound infiltration in managing postoperative pain and total morphine dosage following kidney transplantation. METHODS: In this prospective, randomized, double-blind study; 46 end-stage renal disease patients undergoing kidney transplantation were randomly allocated into 2 groups: a QL group (n = 23) receiving 20 mL of 0.25% bupivacaine using the ultrasound-assisted inside-out technique before wound closure, while the local wound infiltration (LA) group (n = 23) receiving the same dose around the surgical wound and drain at the time of skin closure. The primary outcome measure was the numerical pain rating scale, with secondary outcomes including amount of morphine consumption at various postoperative time points (2nd, 4th, 6th, 12th, 18th and 24th hours). RESULTS: Patients in the QL group had significantly lower numerical rating scale scores at the 2nd and 4th hours, both at rest and during movement (P < .05). Although pain scores at rest and during movement at later time points were lower in the QL group compared to the LA group, these differences were not statistically significant. Cumulative morphine consumption at postoperative 4th, 6th, 12th, 18th and 24th hours was significantly lower in the QL group (P < .05). No patients experienced complications from the QL3 block. CONCLUSION: Ultrasound-assisted inside-out QL3 block significantly reduced postoperative pain levels at the 2nd and 4th hours, both at rest and during movement, and led to a reduction in cumulative morphine consumption from the 4th hour postoperatively, and persisting throughout the 24-hour period.

Real-time and video-recorded pain assessment in beef cattle: clinical application and reliability in young, adult bulls undergoing surgical castration.

Bovine pain assessment relies on validated behavioral scales related to normal and pain-related behaviors. This study investigated the reliability and applicability of real-time and video-recorded pain assessment, and their agreement, in young, adult bulls undergoing surgical castration. Ten Nelore and nine Angus bulls underwent general anesthesia and surgical castration. Three-minute real-time observations and simultaneous videos were recorded at - 48 h (M0), before sedation, under fasting (M1), after surgery, 3 h after sternal recumbency (M2), after rescue analgesia (M3) and at 24 h (M4). Animals received morphine (after M2), dipyrone (after M3), and flunixin meglumine after surgical castration (M4). Two trained evaluators assessed real-time (n = 95) and video-recorded time-points (n = 95) using the Unesp-Botucatu Cattle Pain Scale (UCAPS). Both assessment methods inferred 'very good' reliability (≥ 0.81) with minimal bias, however, video-recorded assessment (4.33 ± 2.84) demonstrated slightly higher scores compared to real-time (3.08 ± 2.84). The results from this study suggest that UCAPS can be used in real-time or video-recorded to assess pain and guide analgesic therapy in cattle.

Comparison of the postoperative effects of the erector spinae plane block and local infiltration analgesia in patients operated with lumbotomy surgery incision: Randomized clinical study.

BACKGROUND: Our aim was to observe the effects of local infiltration analgesia (LIA) or erector spinae plane block (ESPB) methods, which we applied preemptively in patients who were scheduled for surgery with a lumbotomy surgical incision and on intraoperative remifentanil consumption, and to compare the postoperative numerical rating scale (NRS), morphine demand, consumption, and pain degrees. METHODS: Sixty American Society of Anesthesiologists I to III patients aged 18 to 75 years who were due to be operated on with a lumbotomy surgical incision were included in the study. The present study was conducted via prospective, randomized controlled, double-blind trials. After the induction of standard anesthesia, LIA was applied to 30 patients and ESPB was applied to 30 patients preemptively. The dose of remifentanil consumed in the intraoperative period was measured, and the hemodynamic parameters were measured every 5 minutes. Morphine bolus treatment with the postoperative patient-controlled analgesia and rescue analgesia with paracetamol were planned for the patients. Postoperative morphine and additional analgesia consumption, NRS, hemodynamic parameters, and complications were recorded for 48 hours. RESULTS: There was no difference between the groups in terms of demographic and hemodynamic data. The mean consumption of remifentanil was measured as 455 ±â€…165.23 µg in the intraoperative ESPB group and 296.67 ±â€…110.59 µg in the LIA group, and a statistical difference was observed (P = .001). In the postoperative follow-ups, the ESPB group drug consumption and NRS score averages were significantly lower at all times (P = .01; patient-controlled analgesia-morphine, 41.93 ±â€…14.47 mg vs 57.23 ±â€…15.5 mg and additional analgesic-paracetamol: 2.1 ±â€…1.06 vs 4.27 ±â€…1.14 g). The mean duration of additional analgesic intake of the groups was 10.6 ±â€…8.1 in the LIA group, while it was 19.33 ±â€…8.87 in the ESPB group, a significant difference. The patient satisfaction questionnaire was also significantly in favor of ESPB (P = .05). CONCLUSIONS: In conclusion, it has been shown that the intraoperative LIA method is more effective in terms of remifentanil consumption and in controlling pain in operations performed with a flank incision, but the ESPB method provides longer and more effective pain control in postoperative follow-ups.

Effects of Thymbra spicata extract and Thymol on morphine withdrawal syndrome in mice (insights to the liver function, antioxidant, and behavioral responses).

Safe chemicals for drug withdrawal can be extracted from natural sources. This study investigates the effects of clonidine and Thymbra spicata extract (TSE) on mice suffering from morphine withdrawal syndrome. Thymol, which is the active constituent in TSE, was also tested. A total of 90 mice were divided into nine groups. Group 1 was the control group, while Group 2 was given only morphine, and Group 3 received morphine and 0.2 mg/kg of clonidine. Groups 4-6 were given morphine along with 100, 200, and 300 mg/kg of TSE, respectively. Groups 7-9 received morphine plus 30, 60, and 90 mg/kg of Thymol, respectively, for 7 days. An oral naloxone challenge of 3 mg/kg was used to induce withdrawal syndrome in all groups. Improvement of liver enzyme levels (aspartate aminotransferase, alkaline phosphatase, and alanine transaminase) (p < .01) and behavioral responses (frequencies of jumping, frequencies of two-legged standing, Straub tail reaction) (p < .01) were significantly observed in the groups receiving TSE and Thymol (Groups 4-9) compared to Group 2. Additionally, antioxidant activity in these groups was improved compared to Group 2. Nitric oxide significantly decreased in Groups 4 and 6 compared to Groups 2 and 3 (p < .01). Superoxide dismutase increased dramatically in Groups 5, 8, and 9 compared to Groups 2 and 3 (p < .01). Groups 5-9 were significantly different from Group 2 in terms of malondialdehyde levels (p < .01). Certain doses of TSE and Thymol were found to alleviate the narcotics withdrawal symptoms. This similar effect to clonidine can pave the way for their administration in humans.

Attenuation of acute postoperative pain and opioid requirement with the use of magnesium sulfate in patients undergoing limb amputations.

OBJECTIVE: To compare the effects of magnesium sulphate on the total dose of intravenous morphine consumption postoperatively following limb amputations along with rescue analgesia requirement, pain scores and side effects. METHODS: This prospective, triple-blinded, randomised controlled study was conducted from October 2021 to May 2022 at the Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan, and comprised of patients scheduled for limb amputations. They were randomised into 2 equal groups. The anaesthesia protocol was uniform for all patients. Intervention group A was administered 30mg/kg loading dose and 10mg/kg/hr maintenance dose of magnesium sulphate intravenously, while patients in control group B received the same amount of plain isotonic saline. Morphine consumption, including that used for rescue analgesia and patient-controlled analgesia, was measured for 24 hours postoperatively. Numeric rating scale was used for the evaluation of postoperative pain in both groups at 15min, 1h, 2h, at discharge from the post-anaesthesia care unit and at 12h and 24h in the ward. Data was analysed using SPSS 23. RESULTS: Of the 24 patients enrolled, the study was completed by 20(83.33%). There were 10(50%) patients in group A; 8(40%) males and 2(20%) females with mean age 24.8±14.14 years and mean surgery time 130.5±47.86 minutes. There were 10(50%) patients in group B; 8(40%) males and 2(20%) females with mean age 23.2±7.4 years and mean surgery time 117±23.85 minutes (p>0.05). Total morphine used over 24 hours in group A was 16±3.1 mg compared to 29.6±11.2 mg in group B (p<0.05). The time for first use of patient-controlled analgesia after arriving in the postanaesthesia care unit was significantly delayed in group A (72.2±24.95 minutes) compared to that in group B (25±26.68 minutes) (p<0.05). Pain scores were significantly higher in the group B at 15min compared to group A (p<0.05), but not at the rest of the time points (p>0.05). CONCLUSIONS: Intravenous magnesium sulphate proved to be effective in lowering postoperative opioid requirement following limb amputations.

Fracture pain in children in the emergency department: the impact of a new pain management procedure.

PURPOSE: To compare compliance with the French national guidelines before and after the implementation (in 2018) of a new protocol on acute fracture pain management in the pediatric emergency department of a French university medical center. METHODS: We conducted a retrospective, before-after study in patients aged below 16 years presenting at the pediatric emergency department with a fracture. We compared pain management before (in 2017) and after (in 2019 and 2020) implementation of the new procedure. The primary endpoint was appropriate pain management, defined as (i) an appropriate initial assessment of pain, (ii) appropriate treatment with analgesic drugs (acetaminophen for mild pain, acetaminophen and ibuprofen for moderate pain, ibuprofen and morphine for severe pain) and (iii) reassessment of the pain intensity. RESULTS: 572 patients were included (mean age: 6.5 years; male: 60%). 190 in 2017 and 382 in 2019-2020. Pain management was appropriate for 40% of the patients in 2017 and 52% in 2019-2020 (p = 0.004). Pain was rated for 98% of patients in 2017 vs. 100% in 2019-2020 (p = 0.04). The frequency of appropriate treatment for mild pain and moderate pain increased significantly from 52 to 76% and from 0 to 44%, respectively. The administration of ibuprofen increased by 26% points (from 3 to 20 patients treated) and the administration of morphine increased by 29% points (from 1 to 17 patients treated). Pain reassessment rose significantly from 21 to 43%. Levels of compliance with the guidelines were similar in 2019 and 2020. Analgesia was significantly more effective in 2019-2020 than in 2017 (in 20% vs. 14% of the patients, respectively; p = 0.005). CONCLUSION: After the implementation of a new protocol for the management of acute fracture pain, we observed an increase in compliance with the guidelines. Although the use of ibuprofen and morphine rose significantly as did the frequency of pain reassessment, further improvements are required.

Neuraxial Morphine Anesthesia Given During Cesarean Delivery and Risk of Urinary Retention: A Retrospective Study.

BACKGROUND: Cesarean deliveries (CD) are commonly performed using neuraxial anesthesia. The use of neuraxial morphine has proven beneficial in terms of postoperative pain management; however, its effect on postoperative urine retention remains unclear. OBJECTIVES: To determine whether morphine injection into the neuraxis during CD influences postoperative urinary retention rate. METHODS: We conducted a retrospective case-control observational study of patients undergoing CD. We compared patients using morphine injected into the intrathecal or epidural spaces (November 2020 to October 2021) to a historical cohort of patients undergoing CD without morphine (November 2019 to October 2020). The primary outcome was the rate of postoperative overt urinary retention necessitating bladder catheterization. RESULTS: The study group comprised 283 patients, and 313 patients in the control group were eligible for analysis. No differences were found with respect to the baseline demographic and indication for CD. The number of postpartum urinary bladder catheterizations due to urine retention was higher in the study group (5% vs. 1%, P-value = 0.003). No cases of 30-day readmission were recorded. Moreover, patients treated with neuraxial morphine required fewer repeat doses of postoperative anesthesia (oral analgesia 7.4 vs. 10.1, intravenous analgesia 0.29 vs. 0.31, oral opioids 0.06 vs. 3.70, intravenous opioids 0.01 vs. 0.45, P-value < 0.001 for all). CONCLUSIONS: While neuraxial morphine used during CD appears to be safe and effective, the risk of postoperative urinary retention seems to be increased due to its use. Cases of overt urinary retention treated by bladder catheterization does not lead to short-term complications.

The effects of buprenorphine and morphine during pregnancy: Impact of exposure length on maternal brain, behavior, and offspring neurodevelopment.

The escalating incidence of opioid-related issues among pregnant women in the United States underscores the critical necessity to understand the effects of opioid use and Medication for Opioid Use Disorders (MOUDs) during pregnancy. This research employed a translational rodent model to examine the impact of gestational exposure to buprenorphine (BUP) or morphine on maternal behaviors and offspring well-being. Female rats received BUP or morphine before conception, representing established use, with exposure continuing until postnatal day 2 or discontinued on gestational day 19 to mimic treatment cessation before birth. Maternal behaviors - including care, pup retrieval, and preference - as well as hunting behaviors and brain neurotransmitter levels were assessed. Offspring were evaluated for mortality, weight, length, milk bands, surface righting latency, withdrawal symptoms, and brain neurotransmitter levels. Our results reveal that regardless of exposure length (i.e., continued or discontinued), BUP resulted in reduced maternal care in contrast to morphine-exposed and control dams. Opioid exposure altered brain monoamine levels in the dams and offspring, and was associated with increased neonatal mortality, reduced offspring weight, and elevated withdrawal symptoms compared to controls. These findings underscore BUP's potential disruption of maternal care, contributing to increased pup mortality and altered neurodevelopmental outcomes in the offspring. This study calls for more comprehensive research into prenatal BUP exposure effects on the maternal brain and infant development with the aim to mitigate adverse outcomes in humans exposed to opioids during pregnancy.

Pannexin-1 channel inhibition alleviates opioid withdrawal in rodents by modulating locus coeruleus to spinal cord circuitry.

Opioid withdrawal is a liability of chronic opioid use and misuse, impacting people who use prescription or illicit opioids. Hyperactive autonomic output underlies many of the aversive withdrawal symptoms that make it difficult to discontinue chronic opioid use. The locus coeruleus (LC) is an important autonomic centre within the brain with a poorly defined role in opioid withdrawal. We show here that pannexin-1 (Panx1) channels expressed on microglia critically modulate LC activity during opioid withdrawal. Within the LC, we found that spinally projecting tyrosine hydroxylase (TH)-positive neurons (LCspinal) are hyperexcitable during morphine withdrawal, elevating cerebrospinal fluid (CSF) levels of norepinephrine. Pharmacological and chemogenetic silencing of LCspinal neurons or genetic ablation of Panx1 in microglia blunted CSF NE release, reduced LC neuron hyperexcitability, and concomitantly decreased opioid withdrawal behaviours in mice. Using probenecid as an initial lead compound, we designed a compound (EG-2184) with greater potency in blocking Panx1. Treatment with EG-2184 significantly reduced both the physical signs and conditioned place aversion caused by opioid withdrawal in mice, as well as suppressed cue-induced reinstatement of opioid seeking in rats. Together, these findings demonstrate that microglial Panx1 channels modulate LC noradrenergic circuitry during opioid withdrawal and reinstatement. Blocking Panx1 to dampen LC hyperexcitability may therefore provide a therapeutic strategy for alleviating the physical and aversive components of opioid withdrawal.

Continuous Intra-Incisional Bupivacaine for Postoperative Analgesia after Hip Nailing Surgery: A Randomized Clinical Trial.

Background: The effectiveness of continuous wound infiltration (CWI) as a postoperative pain-control technique has been shown in many surgical procedures. This study investigates the effect of CWI of local anesthetic on postoperative pain control in intertrochanteric fracture patients undergoing hip nailing surgery. Methods: In this randomized clinical trial, 48 patients who were scheduled for hip nailing surgery were randomly assigned to receive (n = 24) or not receive (n = 24) bupivacaine infusion through a catheter inside the surgical wound, postoperatively. Pain intensity (NRS), required dose of morphine, and drug-related complications within 24 hours of the intervention were assessed and compared. Results: Pain intensity was significantly lower in the bupivacaine group both during the recovery room stay and in the ward in the first 24 hours after the procedure (P < 0.001). In the recovery room, the control group patients had a higher morphine consumption compared to the bupivacaine group (P < 0.001) and requested it earlier than the bupivacaine group (60 (45-60) vs. 360 (195-480) minutes) (P < 0.001). In the ward, all control group patients used the PCA morphine pump, while only 54% of the bupivacaine group self-administered morphine through the pump, with a significantly lower total morphine consumption (1 (0-2) vs. 10 (5-14) mg, P < 0.001). None of the patients in the bupivacaine group required additional morphine, while 37.5% of the control requested additional morphine (P=0.002). Altogether, the control group had a higher total morphine consumption compared to the bupivacaine group in the first 24 hours (10.5 (6-15.5) vs. 1 (0-2) mg, P < 0.001). Conclusion: CWI of bupivacaine helps better pain reduction during the early postoperative hours while it reduces opioid consumption, minimizes nausea and vomiting, and improves patient satisfaction.