Effects of perioperative low-dose naloxone on the immune system in patients undergoing laparoscopic-assisted total gastrectomy: a randomized controlled trial.

BACKGROUND: Low immune function after laparoscopic total gastrectomy puts patients at risk of infection-related complications. Low-dose naloxone (LDN) can improve the prognosis of patients suffering from chronic inflammatory diseases or autoimmune diseases. The use of LDN during perioperative procedures may reduce perioperative complications. The purpose of this study was to examine the effects of LDN on endogenous immune function in gastric cancer patients and its specific mechanisms through a randomized controlled trial. METHODS: Fifty-five patients who underwent laparoscopic-assisted total gastrectomy were randomly assigned to either a naloxone group (n = 23) or a nonnaloxone group (n = 22). Patients in the naloxone group received 0.05 µg/kg-1.h- 1naloxone from 3 days before surgery to 5 days after surgery via a patient-controlled intravenous injection (PCIA) pump, and patients in the nonnaloxone group did not receive special treatment. The primary outcomes were the rates of postoperative complications and immune function assessed by NK cell, CD3+ T cell, CD4+ T cell, CD8+ T cell, WBC count, neutrophil percentage, and IL-6 and calcitonin levels. The secondary outcomes were the expression levels of TLR4 (Toll-like receptor), IL-6 and TNF-α in gastric cancer tissue. RESULTS: Compared with the nonnaloxone group, the naloxone group exhibited a lower incidence of infection (in the incision, abdomen, and lungs) (P < 0.05). The numbers of NK cells and CD8+ T cells in the naloxone group were significantly greater than those in the nonnaloxone group at 24 h after surgery (P < 0.05) and at 96 h after surgery (P < 0.05). Compared with those in the nonnaloxone group, the CD3 + T-cell (P < 0.05) and CD4 + T-cell (P < 0.01) counts were significantly lower in the naloxone group 24 h after surgery. At 24 h and 96 h after surgery, the WBC count (P < 0.05) and neutrophil percentage (P < 0.05) were significantly greater in the nonnaloxone group. The levels of IL-6 (P < 0.05) and calcitonin in the nonnaloxone group were significantly greater at 24 h after surgery. At 24 h following surgery, the nonnaloxone group had significantly greater levels of IL-6 (P < 0.05) and calcitonin than did the naloxone group. Compared with those in the naloxone group, the expression levels of TLR4 (P < 0.05) in gastric cancer tissue in the naloxone group were greater; however, the expression levels of IL-6 (P < 0.01) and TNF-α (P < 0.01) in the naloxone group were greater than those in the nonnaloxone group. CONCLUSION: Laparoscopic total gastrectomy patients can benefit from 0.05 ug/kg- 1. h- 1 naloxone by reducing their risk of infection. It is possible that LDN alters the number of cells in lymphocyte subpopulations, such as NK cells, CD3 + T cells, and CD4 + T cells, and the CD4+/CD8 + T-cell ratio or alters TLR4 receptor expression in immune cells, thereby altering immune cell activity. TRIAL REGISTRATION: The trial was registered at the Chinese Clinical Trial Registry on 24/11/2023 (ChiCTR2300077948).

Observation of the efficacy of naloxone combined with acyclovir in the treatment of children viral encephalitis and its impacts on IL-1 and IL-6.

OBJECTIVE: To analyze the clinical efficacy of naloxone combined with acyclovir in the treatment of children viral encephalitis and the impacts on inflammatory factors IL-1 and IL-6. PATIENTS AND METHODS: 96 children with viral encephalitis were retrospectively analyzed. They were treated from July 2013 to January 2014 in our hospital. They were divided into control group (45 cases treated with acyclovir) and observation group (51 cases treated with acyclovir combined with naloxone). Both groups were treated with comprehensive measures. Changes of the content of serum IL-1 and IL-6 in the two groups before and after treatment were monitored by enzyme-linked immunosorbent assay (ELISA). Signs, recovery time of clinical symptoms, total effective rate, occurrence of adverse reactions and adverse reactions after treatment of children in the two groups were compared. RESULTS: Levels of serum IL-1 and IL-6 of children in the control group and the observation group decreased after treatment, and the decrease was greater in the observation group (p<0.05). Signs and recovery time of clinical symptoms of the observation group were significantly shorter than that of the control group (p<0.05). Indexes of serum in the observation group were significantly lower than those of the control group after treatment (p<0.05). The total effective rate of the observation group was significantly higher than that of the control group (p<0.05). The prevalence of adverse reactions and sequelae in the observation group were lower than those in the control group (p<0.05). CONCLUSIONS: In the treatment of children, viral encephalitis has naloxone combined with ganciclovir had a more significant effect on the decrease of levels of serum IL-1 and IL-6; naloxone combined with acyclovir in the treatment of children viral encephalitis had better effects, lower adverse reactions and lower prevalence of sequelae compared with sole medication, which is worth clinical promotion.

Implication of Opioid Receptors in the Antihypertensive Effect of a Novel Chicken Foot-Derived Peptide.

The peptide AVFQHNCQE demonstrated to produce nitric oxide-mediated antihypertensive effect. This study investigates the bioavailability and the opioid-like activity of this peptide after its oral administration. For this purpose, in silico and in vitro approaches were used to study the peptide susceptibility to GI digestion. In addition, AVFQHNCQE absorption was studied both in vitro by using Caco-2 cell monolayers and in vivo evaluating peptide presence in plasma from Wistar rats by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and by ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Both in vivo and in vitro experiments demonstrated that peptide AVFQHNCQE was not absorbed. Thus, the potential involvement of opioid receptors in the BP-lowering effect of AVFQHNCQE was studied in the presence of opioid receptors-antagonist Naloxone. No changes in blood pressure were recorded in rats administered Naloxone, demonstrating that AVFQHNCQE antihypertensive effect is mediated through its interaction with opioid receptors. AVFQHNCQE opioid-like activity would clarify the antihypertensive properties of AVFQHNCQE despite its lack of absorption.

Lemairamin, isolated from the Zanthoxylum plants, alleviates pain hypersensitivity via spinal α7 nicotinic acetylcholine receptors.

Lemairamin (also known as wgx-50), is isolated from the pericarps of the Zanthoxylum plants. As an agonist of α7 nicotinic acetylcholine receptors (α7nAChRs), it can reduce neuroinflammation in Alzheimer's disease. This study evaluated its antinociceptive effects in pain hypersensitivity and explored the underlying mechanisms. The data showed that subcutaneous lemairamin injection dose-dependently inhibited formalin-induced tonic pain but not acute nociception in mice and rats, while intrathecal lemairamin injection also dose-dependently produced mechanical antiallodynia in the ipsilateral hindpaws of neuropathic and bone cancer pain rats without affecting mechanical thresholds in the contralateral hindpaws. Multiple bi-daily lemairamin injections for 7 days did not induce mechanical antiallodynic tolerance in neuropathic rats. Moreover, the antinociceptive effects of lemairamin in formalin-induced tonic pain and mechanical antiallodynia in neuropathic pain were suppressed by the α7nAChR antagonist methyllycaconitine. In an α7nAChR antagonist-reversible manner, intrathecal lemairamin also stimulated spinal expression of IL-10 and ß-endorphin, while lemairamin treatment induced IL-10 and ß-endorphin expression in primary spinal microglial cells. In addition, intrathecal injection of a microglial activation inhibitor minocycline, anti-IL-10 antibody, anti-ß-endorphin antiserum or µ-opioid receptor-preferred antagonist naloxone was all able to block lemairamin-induced mechanical antiallodynia in neuropathic pain. These data demonstrated that lemairamin could produce antinociception in pain hypersensitivity through the spinal IL-10/ß-endorphin pathway following α7nAChR activation.

Genetic knockout of the G protein-coupled estrogen receptor 1 facilitates the acquisition of morphine-induced conditioned place preference and aversion in mice.

Drug addiction is considered the pathological usurpation of normal learning and memory. G protein-coupled estrogen receptor 1 (GPER1) plays an important role in normal learning and memory, but the effect of GPER1 on addiction-related pathological memory has not been reported. Our study used GPER1 knockout (GPER1 KO) and wild-type (WT) mice to compare the sensitivity differences of morphine- and sucrose-induced conditioned place preference (CPP) and naloxone-induced conditioned place aversion (CPA), and differences in dopamine (DA) content in the nucleus accumbens (NAc) were determined by high performance liquid chromatography (HPLC). The results showed that GPER1 KO mice showed higher sensitivity to morphine-induced CPP and naloxone-induced CPA, and corresponding to the behavioral effect, the DA content in the NAc of GPER1 KO mice was significantly higher than that of WT mice. Interestingly, the sensitivity of GPER1 KO mice to sucrose-induced CPP did not differ from that of the WT mice, and there was no significant difference in the DA content in the NAc between the two genotypes of mice. GPER1 knockout promoted the formation of morphine addiction-related positive and aversive memory, and its molecular biological mechanism may be associated with increased DA content in the NAc. Therefore, GPER1 plays an important role in the formation of addiction-related pathological memory and may become a potential molecular target for drug addiction therapy.

Prolonged-Release (PR) Oxycodone/Naloxone Improves Bowel Function Compared with Oxycodone PR and Provides Effective Analgesia in Chinese Patients with Non-malignant Pain: A Randomized, Double-Blind Trial.

INTRODUCTION: Prolonged-release oxycodone/naloxone (OXN PR), combining an opioid analgesic with selective blockade of enteric µ-opioid receptors, provided effective analgesia and improved bowel function in patients with moderate-to-severe pain and opioid-induced constipation in clinical trials predominantly conducted in Western countries. This double-blind randomized controlled trial investigated OXN PR (N = 116) versus prolonged-release oxycodone (OXY PR, N = 115) for 8 weeks at doses up to 50 mg/day in patients with moderate-to-severe, chronic, non-malignant musculoskeletal pain and opioid-induced constipation recruited in China. METHODS: A total of 234 patients at least 18 years of age with non-malignant musculoskeletal pain for more than 4 weeks that was moderate-to-severe in intensity and required round-the-clock opioid therapy were randomized (1:1) to OXN PR or OXY PR. The primary endpoint was bowel function using the Bowel Function Index (BFI). Secondary endpoints included safety, Brief Pain Inventory-Short Form (BPI-SF), use of analgesic and laxative rescue medication, and health-related quality of life (EQ-5D). RESULTS: While BFI scores were comparable at baseline, at week 8 improvements were greater with OXN PR vs OXY PR (least squares mean [LSM] difference (95% CI) - 9.1 (- 14.0, - 4.2); P < 0.001. From weeks 2 to 8, mean BFI scores were in the range of normal bowel function (≤ 28.8) with OXN PR but were in the range of constipation (> 28.8) at all timepoints with OXY PR. Analgesia with OXN PR was similar and non-inferior to OXY PR on the basis of modified BPI-SF average 24-h pain scores at week 8: LSM difference (95% CI) - 0.3 (- 0.5, - 0.1); P < 0.001. The most frequent treatment-related AEs were nausea (OXN PR 5% vs OXY PR 6%) and dizziness (4% vs 4%). CONCLUSION: OXN PR provided clinically meaningful improvements in bowel function and effective analgesia in Chinese patients with moderate-to-severe musculoskeletal pain and pre-existing opioid-induced constipation. TRIAL REGISTRATION: ClinicalTrials.gov, identifier NCT01918098.

The Effect of Ultra-low-dose Intrathecal Naloxone on Pain Intensity After Lumbar Laminectomy With Spinal Fusion: A Randomized Controlled Trial.

BACKGROUND: Despite advances in pain management, several patients continue to experience severe acute pain after lumbar spine surgery. The aim of this study was to assess the safety and effectiveness of single ultra-low-dose intrathecal (IT) naloxone in combination with IT morphine for reducing pain intensity, pruritus, nausea, and vomiting in patients undergoing lumbar laminectomy with spinal fusion. MATERIALS AND METHODS: In this double-blind trial, patients scheduled for lumbar laminectomy with spinal fusion were randomly assigned to receive single ultra-low-dose IT naloxone (20 µg) and IT morphine (0.2 mg) (group M+N) or IT morphine (0.2 mg) alone (group M). The severity of postoperative pain, pruritus and nausea, and frequency of vomiting were assessed at recovery from anesthesia and, subsequently, at 1, 3, 6, 12, and 24 hours postoperatively using an 11-point (0-10) visual analogue scale. RESULTS: A total of 77 patients completed the study, and there were significant differences in postoperative pain, pruritus, and nausea visual analogue scale between the groups (P<0.05). After adjusting for body mass index and surgery duration, IT naloxone administration reduced the pain score (coefficient=1.84; 95% confidence interval [CI], 1.05-2.63; P<0.001), and the scores of pruritus and nausea (coefficient=0.9; 95% CI, 0.44-1.37; P<0.001 and coefficient=0.71; 95% CI, 0.12-1.31; P=0.02, respectively) compared with IT morphine alone. No serious adverse effects were observed. CONCLUSIONS: The addition of ultra-low-dose IT naloxone to IT morphine provides excellent postoperative pain management and effectively controls pruritus and nausea in patients undergoing laminectomy with spinal fusion.

Implication of Opioid Receptors in the Antihypertensive Effect of a Bovine Casein Hydrolysate and αs1-Casein-Derived Peptides.

The antihypertensive activity of two αs1-casein-derived peptides and casein hydrolysate containing these sequences was evaluated in the presence of naloxone. The activity was abolished by this opioid antagonist at 2, 4, and 6 h post-administration. Similarly, the antihypertensive effect of the αs1-casein peptides 90RYLGY94 (-23.8 ± 2.5 mmHg) and 143AYFYPEL149 (-21.1 ± 3.2 mmHg) at 5 mg/kg of body weight was antagonized by the co-administration of naloxone. Because peptide 143AYFYPEL149 had recently shown opioid activity, a molecular dynamic simulation of this peptide with human µ-opioid receptor was performed to demonstrate its favorable structure and interaction energy, despite the presence of Ala at the N terminus. Altogether, these results revealed that the in vivo effect on systolic blood pressure of the studied αs1-casein peptides is mediated by interaction with opioid receptors and the antihypertensive activity of casein hydrolysate can be very likely ascribed to them with the possible contribution of other mechanisms.

The effect of a low-dose naloxone infusion on the incidence of respiratory depression after intrathecal morphine administration for major open hepatobiliary surgery: a randomised controlled trial.

Intrathecal morphine is an analgesic option for major hepatopancreaticobiliary procedures but is associated with a risk of respiratory depression. We hypothesised that a postoperative low-dose naloxone infusion would reduce the incidence of respiratory depression without an increase in pain scores. Patients scheduled for major open hepatopancreaticobiliary surgery and who were receiving 10 µg.kg-1 intrathecal morphine were eligible for inclusion. Patients were allocated randomly to receive a postoperative infusion of naloxone 5 µg.kg-1 .h-1 (naloxone group) or saline at an identical infusion rate (control group) until the morning after surgery. Clinicians, nursing staff and patients were blinded to group allocation. The primary outcome measure was the incidence of respiratory depression (respiratory rate < 10 breaths.min-1 and/or oxygen saturation < 90%). Secondary outcome measures included: arterial partial pressure of carbon dioxide; pain score; requirement for supplemental analgesic; and incidence of nausea and vomiting, pruritus and sedation. In total, data from 95 patients (48 in the naloxone group and 47 in the control group) were analysed. The incidence of respiratory depression was lower in the naloxone group compared with the control group (10/48 vs. 21/47 patients, respectively; p = 0.037, relative risk 0.47 (95%CI 0.25-0.87). Maximum pain scores were greater for patients allocated to the naloxone group compared with control (median 5 (95%CI 4-6) vs. 4 (95%CI 2-4), respectively; p < 0.001). A low-dose naloxone infusion decreases the incidence of respiratory depression following intrathecal morphine administration in patients having major hepatopancreaticobiliary surgery at the expense of a small increase in postoperative pain.

Complete essential oils of Laurus nobilisinducing antinociceptiveaction by opioid mechanism in C-Reflex and spinal Wind-Up model in rat / Aceites esenciales totales de Laurus nobilis inducen acción antinociceptivamediante mecanismo opioide en el modelode Reflejo-C y Wind-Up espinal en ratas

The essential oil of Laurus nobilis L. was used to test their antinociceptive efficacy. It was applied intraperitoneally (i.p.) to rats subjected to a nociception test (C reflex and spinal wind-up). The results showed that the essential oil applied at higher doses (0.06 mg/Kg) causes a complete abolition of the spinal wind-up, while the C reflex was unchanged, indicating a clear antinociceptive effect. At lower concentrations (0.012 mg/Kg), there was a lowering in the wind-up by 85% within ten minutes of the essential i.p. oil application. Interestingly, there was an effect of naloxone (0.08 mg/Kg i.p.) When applied, a change occurs that almost entirely reversed the antinociception caused by the essential oil from Laurus nobilis. We conclude that there is a significant antinociceptive effect of the essential oil of Laurus nobilis subjected to electric nociception. In addition, it was observed that naloxone reversed the antinociceptive effect (wind-up) produced by Laurus nobilis.

El aceite esencial de Laurus nobilis L. se usó para probar su eficacia antinociceptiva. Se aplicó por vía intraperitoneal (i.p.) a ratas sometidas a una prueba de nocicepción (reflejo-C y wind-up espinal). Los resultados mostraron que el aceite esencial aplicado a dosis más altas (0.06 mg/Kg) abolió completamente el wind-up espinal, mientras que el reflejo-C no cambió, lo que indica un claro efecto antinociceptivo. A concentraciones más bajas (0.012 mg/Kg), hubo una disminución en el wind-up en un 85% dentro de los diez minutos del i.p. la aplicación del aceite esencial. Curiosamente, hubo un efecto de la naloxona (0.08 mg/Kg i.p.) la cual revierte casi por completo la antinocicepción causada por el aceite esencial de Laurus nobilis. Concluimos que existe un efecto antinociceptivo significativo del aceite esencial de Laurus nobilis sometido a nocicepción eléctrica. Además, se observó que la naloxona revirtió el efecto antinociceptivo (wind-up) producido por Laurus nobilis.

Effect of low dose naloxone on the immune system function of a patient undergoing video-assisted thoracoscopic resection of lung cancer with sufentanil controlled analgesia - a randomized controlled trial.

BACKGROUND: Perioperative immune function plays an important role in the prognosis of patients. Several studies have indicated that low-dose opioid receptor blockers can improve immune function. METHODS: Sixty-nine patients undergoing video-assisted thoracoscopic resection of the lung cancer were randomly assigned to either the naloxone group (n = 35) or the non-naloxone group (n = 34) for postoperative analgesia during the first 48 h after the operation. Both groups received sufentanil and palonosetron via postoperative analgesia pump, while 0.05 µg·kg- 1·h- 1 naloxone was added in naloxone group. The primary outcomes were the level of opioid growth factor (OGF) and immune function assessed by natural killer cells and CD4+/CD8+ T-cell ratio. Second outcomes were assessed by the intensity of postoperative pain, postoperative rescue analgesia dose, postoperative nausea and vomiting (PONV). RESULTS: The level of OGF in the naloxone group increased significantly at 24 h (p<0.001) and 48 h after the operation (P < 0.01). The natural killer cells (P < 0.05) and CD4+/CD8+ T-cell ratio (P < 0.01) in the naloxone group increased significantly at 48 h after the operation. The rest VAS scores were better with naloxone at 12 and 24 h after operation(P < 0.05), and the coughing VAS scores were better with naloxone at 48 h after the operation(P < 0.05). The consumption of postoperative rescue analgesics in the naloxone group was lower (0.00(0.00-0.00) vs 25.00(0.00-62.50)), P < 0.05). Postoperative nausea scores at 24 h after operation decreased in naloxone group(0.00 (0.00-0.00) vs 1.00 (0.00-2.00), P < 0.01). CONCLUSION: Infusion of 0.05 µg·kg- 1·h- 1 naloxone for patients undergoing sufentanil-controlled analgesia for postoperative pain can significantly increase the level of OGF, natural killer cells, and CD4+/CD8+ T-cell ratio compared with non-naloxone group, and postoperative pain intensity, request for rescue analgesics, and opioid-related side effects can also be reduced. TRIAL REGISTRATION: The trial was registered at the Chinese Clinical Trial Registry on January 26, 2019 (ChiCTR1900021043).

Pearls for opioid use in seriously ill patients.

Opioids are often the foundation of pain management in seriously ill patients. Unfortunately, even experienced providers carry with them information that they consider "fact", when this information is not based on scientific evidence, but on "myth". Several topics were elicited based on common beliefs and misconceptions in clinical practice. These were identified via a survey of pharmacist pain and palliative care providers. Pearls from these topics were chosen that were based on evidence and would have the greatest bearing on clinical practice. The pearls address topics such as not using opioids as first-line analgesics for all types of pain, opioid-induced hyperalgesia, opioid risk management in cancer patients, use of buprenorphine in hospice and palliative care settings and use of naloxone in seriously ill patients. The pearls are supported by clinical evidence extracted from several references. They are intended to make readers give thought to opioid therapy which is strictly evidence-based, and not historical or anecdote-based. Practical recommendations are provided to give readers a starting point to base clinical decisions going forward. Readers may discover that "facts" they once learned about opioid use in seriously ill patients are actually "myths" that are a figment of the past.

Urban, individuals of color are impacted by fentanyl-contaminated heroin.

The present phase of the overdose epidemic is characterized by fentanyl-contaminated heroin, particularly in the eastern United States (U.S.). However, there is little research examining how changes in drug potency are affecting urban, racial minority individuals who have been affected by both the "old" epidemic of the 1940s through 1980s, as well as the "new" present day epidemic. A focus on the drug using experiences of racial minorities is needed to avoid perpetuating discriminatory responses to drug use in communities of color, which have characterized past U.S. policies. This qualitative study was conducted from March through June 2018 to examine recent experiences of urban, individuals of color who inject drugs to assess the impact of the current overdose epidemic on this understudied population. Interviews were conducted with 25 people who reported current injection drug use. The interviews were transcribed and analyzed using a general inductive approach to identify major themes. Fifteen of 25 participants reported experiencing a non-fatal overdose in the past two years; eight suspected their overdose was fentanyl-related. Likewise, 15 had ever witnessed someone else overdose at least once. Overdoses that required multiple doses of naloxone were also reported. Participants employed several methods to attempt to detect the presence of fentanyl in their drugs, with varying degrees of success. Carrying naloxone and utilizing trusted drug sellers (often those who also use) were strategies used to minimize risk of overdose. Contaminated heroin and increased risk for overdose was often encountered when trusted sources were unavailable. This population is suffering from high rates of recent overdose. Removal of trusted drug sources from a community may inadvertently increase overdose risk. Ensuring access to harm reduction resources (naloxone, drug testing strips) will remain important for addressing ever-increasing rates of overdose among all populations affected.

Development of an algorithm to identify inpatient opioid-related overdoses and oversedation using electronic data.

PURPOSE: To facilitate surveillance and evaluate interventions addressing opioid-related overdoses, algorithms are needed for use in large health care databases to identify and differentiate community-occurring opioid-related overdoses from inpatient-occurring opioid-related overdose/oversedation. METHODS: Data were from Kaiser Permanente Northwest (KPNW), a large integrated health plan. We iteratively developed and evaluated an algorithm for electronically identifying inpatient overdose/oversedation in KPNW hospitals from 1 January 2008 to 31 December 2014. Chart audits assessed accuracy; data sources included administrative and clinical records. RESULTS: The best-performing algorithm used these rules: (1) Include events with opioids administered in an inpatient setting (including emergency department/urgent care) followed by naloxone administration within 275 hours of continuous inpatient stay; (2) exclude events with electroconvulsive therapy procedure codes; and (3) exclude events in which an opioid was administered prior to hospital discharge and followed by readmission with subsequent naloxone administration. Using this algorithm, we identified 870 suspect inpatient overdose/oversedation events and chart audited a random sample of 235. Of the random sample, 185 (78.7%) were deemed overdoses/oversedation, 37 (15.5%) were not, and 13 (5.5%) were possible cases. The number of hours between time of opioid and naloxone administration did not affect algorithm accuracy. When "possible" overdoses/oversedations were included with confirmed events, overall positive predictive value (PPV) was very good (PPV = 84.0%). Additionally, PPV was reasonable when evaluated specifically for hospital stays with emergency/urgent care admissions (PPV = 77.0%) and excellent for elective surgery admissions (PPV = 97.0%). CONCLUSIONS: Algorithm performance was reasonable for identifying inpatient overdose/oversedation with best performance among elective surgery patients.

Retrospective Review of Need for Delayed Naloxone or Oxygen in Emergency Department Patients Receiving Naloxone for Heroin Reversal.

BACKGROUND: Emergency departments (EDs) are experiencing an increasing number of heroin overdose visits. Currently, there is no generally agreed upon ED observation period for heroin overdose patients who receive naloxone. OBJECTIVES: We aimed to determine the safety of a 2-h observation period for heroin overdose patients who receive naloxone. METHODS: We performed a chart review of all patients who presented with any opioid-related complaint between 2009 and 2014 to our urban academic trauma center. Subset analysis of patients with isolated heroin overdose who received naloxone was performed, with the intent of excluding patients intoxicated with long-acting/enteral opioids. The primary outcome was the number of patients who required delayed intervention-specifically, additional naloxone or supplemental oxygen. RESULTS: Between 2009 and 2014, we recorded 806 visits to our ED for heroin use after receiving naloxone. Twenty-nine patients (3.6%) received a repeat dose of naloxone, and 17 patients (2%) received oxygen ≥2 h after initial naloxone administration. Our 2-h intervention rate was 4.6% (N = 37). This decreased to 1.9% (N = 15) after 3 h and 0.9% (N = 7) after 4 h. Patients with polysubstance use were more likely to receive repeat naloxone (p < 0.01), but not oxygen (p = 0.10). Preexisting cardiopulmonary conditions did not correlate with a need for supplemental oxygen (p = 0.24) or repeat naloxone (p = 0.30). CONCLUSIONS: A 2-h ED observation period for heroin overdose patients reversed with naloxone resulted in a delayed intervention rate of 5%. Clinicians may consider a 3-h observation period, with extra scrutiny in polysubstance abuse.

Comparison of the Pharmacokinetic Properties of Naloxone Following the Use of FDA-Approved Intranasal and Intramuscular Devices Versus a Common Improvised Nasal Naloxone Device.

For more than a decade, first responders and the general public have been able to treat suspected opioid overdoses using an improvised nasal naloxone device (INND) constructed from a prefilled syringe containing 2 mg of naloxone (1 mg/mL) attached to a mucosal atomization device. In recent years, the U.S. Food and Drug Administration (FDA)-approved Ezvio, an autoinjector that delivers 2 mg by intramuscular injection and Narcan nasal spray (2- and 4-mg strengths; 0.1 mL/dose) for the emergency treatment of a known or suspected opioid overdose. The present study was conducted to compare the pharmacokinetics of naloxone using the FDA-approved devices (each administered once) and either 1 or 2 administrations using the INND. When naloxone was administered twice using the improvised device, the doses were separated by 2 minutes. The highest maximum plasma concentration was achieved using the 4-mg FDA-approved spray. The highest exposures at 5 minutes postdose, based on AUC values, were after administration with the autoinjector and the 4-mg FDA-approved spray; at 10, 15, and 20 minutes postdose, the latter yielded the greatest exposure. Even after 2 administrations, the INND failed to achieve naloxone plasma levels comparable to the FDA-approved devices at any time. The ease of use and higher plasma concentrations achieved using the 4-mg FDA-approved spray, compared with the INND, should be considered when deciding which naloxone device to use.

Results of a Naloxone Screening Quality-Improvement Project in an Academic Emergency Department.

BACKGROUND: The Emergency Department (ED) is a medical setting increasingly utilized by opioid users. In January 2016, our health system initiated a take-home naloxone education and distribution program. From July to August 2016, screening was performed in the ED to identify patients for take-home naloxone. OBJECTIVE: To evaluate the outcomes of routine screening for take-home naloxone in the ED setting and to determine key screening questions. Secondary analysis of Electronic Health Records for discrete elements that could help identify individuals for naloxone. METHODS: This is a single-center, retrospective cohort study conducted at two EDs within an academic health system. A screening tool was verbally administered to a convenience sample of ED patients as part of a pilot project to identify patients for overdose education and naloxone. Patient charts were reviewed retrospectively for pre-determined historical elements, medications prescribed, and substance use history. Descriptive and comparative analysis using Fisher two-tailed tests were performed with regard to historical elements, naloxone recommendation and prescription. RESULTS: A total of 182 patients were included. Following screening, 58 (31.9%) were identified as candidates for take-home naloxone. Of those, 36 (62.1%) accepted naloxone recommendation and 19 (32.8%) were prescribed naloxone. Individuals not prescribed naloxone despite recommendation either declined naloxone 22 (37.9%) or were not prescribed naloxone 17 (29.3%). Subanalysis of questions with binary yes/no answers (N = 171) demonstrated significant prediction of both naloxone recommendation (ROC = 0.944) and prescription (ROC = 0.897). CONCLUSIONS: Routine screening for take-home naloxone can help identify patients at-risk for opioid overdose and increase naloxone access in the ED.

Elective Naloxone-Induced Opioid Withdrawal for Rapid Initiation of Medication-Assisted Treatment of Opioid Use Disorder.

We present a case of elective naloxone-induced opioid withdrawal followed by buprenorphine rescue to initiate opioid use disorder treatment in the emergency department. This strategy may represent a safe alternative to prescribing buprenorphine for outpatient initiation, a method that puts the patient at risk for complications of unmonitored opioid withdrawal, including relapse. After confirmation that the naloxone-induced withdrawal was adequately treated with buprenorphine, the patient was discharged with prescribed buprenorphine to follow up in an addiction medicine clinic, where he was treated 2 days later.

Suppression of Human Natural Killer Cells by Different Classes of Opioids.

BACKGROUND: The use of regional and other opioid-sparing forms of anesthesia has been associated with a decrease in the recurrence of certain malignancies. Direct suppression of human natural killer cells by opioids has been postulated to explain this observation. However, the effect of different classes of opioids on suppression of natural killer cell cytotoxicity has not been systematically characterized. METHODS: After confirming that freshly isolated natural killer cells from peripheral human blood express opioid receptors, cells were incubated with increasing concentrations of clinically used or receptor-specific opioid agonists. We also evaluated the effect of pretreatment with receptor-specific antagonists or naloxone. Treated natural killer cells were then coincubated with a carboxyfluorescein succinimidyl ester-labeled target tumor cell line, K562. Annexin V staining was used to compare the percent of tumor cell apoptosis in the presence of opioid-pretreated and untreated natural killer cells. Treated samples were compared to untreated samples using Kruskal-Wallis tests with a post hoc Dunn correction. RESULTS: Morphine, methadone, buprenorphine, loperamide, [D-Ala2, N-MePhe4, Gly-ol]-enkephalin, and U-50488 significantly decreased natural killer cell cytotoxicity. When natural killer cells were pretreated with naloxone, cyprodime, and nor-binaltorphimine before exposure to morphine, there was no difference in natural killer cytotoxicity, compared to the amount observed by untreated natural killer cells. Fentanyl, O-desmethyltramadol, and [D-Pen2,D-Pen5] enkephalin did not change natural killer cell cytotoxicity compare to untreated natural killer cells. CONCLUSIONS: Incubation of isolated natural killer cells with certain opioids causes a decrease in activity that is not observed after naloxone pretreatment. Suppression of natural killer cell cytotoxicity was observed with µ- and κ-receptor agonists but not δ-receptor agonists. These data suggest that the effect is mediated by µ- and κ-receptor agonism and that suppression is similar with many clinically used opioids.