Concomitant use of pre-emptive analgesia with local and general anesthesia in rat uterine pain surgical model.

Preemptive analgesia is used for postoperative pain management, providing pain relief with few adverse effects. In this study, the effect of a preemptive regime on rat behavior and c-fos expression in the spinal cord of the uterine surgical pain model was evaluated. It was a lab-based experimental study in which 60 female Sprague-Dawley rats; eight to 10 weeks old, weighing 150-300 gm were used. The rats were divided into two main groups: (i) superficial pain group (SG) (with skin incision only), (ii) deep pain group (with skin and uterine incisions). Each group was further divided into three subgroups based on the type of preemptive analgesia administered i.e., "tramadol, buprenorphine, and saline subgroups." Pain behavior was evaluated using the "Rat Grimace Scale" (RGS) at 2, 4, 6, 9 and 24 h post-surgery. Additionally, c-fos immunohistochemistry was performed on sections from spinal dorsal horn (T12-L2), and its expression was evaluated using optical density and mean cell count 2 hours postoperatively. Significant reduction in the RGS was noted in both the superficial and deep pain groups within the tramadol and buprenorphine subgroups when compared to the saline subgroup (p ≤ .05). There was a significant decrease in c-fos expression both in terms of number of c-fos positive cells and the optical density across the superficial laminae and lamina X of the spinal dorsal horn in both SD and DG (p ≤ .05). In contrast, the saline group exhibited c-fos expression primarily in laminae I-II and III-IV for both superficial and deep pain groups and lamina X in the deep pain group only (p ≤ .05). Hence, a preemptive regimen results in significant suppression of both superficial and deep components of pain transmission. These findings provide compelling evidence of the analgesic efficacy of preemptive treatment in alleviating pain response associated with uterine surgery.

Perioperative pain optimization in the age of the opioid epidemic.

PURPOSE OF REVIEW: The opioid epidemic remains a constant and increasing threat to our society with overdoses and overdose deaths rising significantly during the COVID-19 pandemic. Growing evidence suggests a link between perioperative opioid use, postoperative opioid prescribing, and the development of opioid use disorder (OUD). As a result, strategies to better optimize pain management during the perioperative period are urgently needed. The purpose of this review is to summarize the most recent multimodal analgesia (MMA) recommendations, summarize evidence for efficacy surrounding the increased utilization of Enhanced Recovery After Surgery (ERAS) protocols, and discuss the implications for rising use of buprenorphine for OUD patients who present for surgery. In addition, this review will explore opportunities to expand our treatment of complex patients via transitional pain services. RECENT FINDINGS: There is ample evidence to support the benefits of MMA. However, optimal drug combinations remain understudied, presenting a target area for future research. ERAS protocols provide a more systematic and targeted approach for implementing MMA. ERAS protocols also allow for a more comprehensive approach to perioperative pain management by necessitating the involvement of surgical specialists. Increasingly, OUD patients taking buprenorphine are presenting for surgery. Recent guidance from a multisociety OUD working group recommends that buprenorphine not be routinely discontinued or tapered perioperatively. Lastly, there is emerging evidence to justify the use of transitional pain services for more comprehensive treatment of complex patients, like those with chronic pain, preoperative opioid tolerance, or substance use disorder. SUMMARY: Perioperative physicians must be aware of the impact of the opioid epidemic and explore methods like MMA techniques, ERAS protocols, and transitional pain services to improve the perioperative pain experience and decrease the risks of opioid-related harm.

Dysphagia as a Missing Link Between Post-surgical- and Opioid-Related Pneumonia.

PURPOSE: Postoperative pneumonia remains a common complication of surgery, despite increased attention. The purpose of our study was to determine the effects of routine surgery and post-surgical opioid administration on airway protection risk. METHODS: Eight healthy adult cats were evaluated to determine changes in airway protection status and for evidence of dysphagia in two experiments. (1) In four female cats, airway protection status was tracked following routine abdominal surgery (spay surgery) plus low-dose opioid administration (buprenorphine 0.015 mg/kg, IM, q8-12 h; n = 5). (2) Using a cross-over design, four naive cats (2 male, 2 female) were treated with moderate-dose (0.02 mg/kg) or high-dose (0.04 mg/kg) buprenorphine (IM, q8-12 h; n = 5). RESULTS: Airway protection was significantly affected in both experiments, but the most severe deficits occurred post-surgically as 75% of the animals exhibited silent aspiration. CONCLUSION: Oropharyngeal swallow is impaired by the partial mu-opioid receptor agonist buprenorphine, most remarkably in the postoperative setting. These findings have implications for the prevention and management of aspiration pneumonia in vulnerable populations.

Combined segmental spinal epidural for major spine surgery: a case report.

A woman in her mid-50s, hesitant about general anaesthesia due to a difficult airway, opted for neuraxial anaesthesia for L4 laminectomy with pedicle screw fixation (L3-L5). Preoperatively, she received 150 µg buprenorphine and 1 mg midazolam. In lateral position, a T8-T9 epidural catheter was placed, followed by segmental spinal anaesthesia (2.5 mL 0.5% hyperbaric bupivacaine+30 µg clonidine) at T10-T11. Prone positioning was executed using standard techniques. During the 6-7 hours surgery, three 7 mL epidural top-ups (2% lignocaine epinephrine) were administered at 90 min intervals. Haemodynamics remained stable with 2.5 L crystalloids, 350 mL packed red cells and three ephedrine doses (6 mg each). Sedation included 150 µg buprenorphine and two 1 mg midazolam doses. Postoperatively, she received epidural 0.25% bupivacaine for 2 days, systemic analgesics and was discharged on the sixth day.

Relationship between opioid cross-tolerance during buprenorphine stabilization and return to opioid use during buprenorphine dose tapering.

RATIONALE: Opioid injection drug use (IDU) has been linked to a more severe pattern of use (e.g. tolerance, overdose risk) and shorter retention in treatment, which may undermine abstinence attempts. OBJECTIVES: This secondary data analysis of four human laboratory studies investigated whether current opioid IDU modulates subjective abuse liability responses to high-dose hydromorphone during intermediate-dose buprenorphine stabilization (designed to suppress withdrawal but allow surmountable agonist effects), and whether hydromorphone response magnitude predicts latency of return to opioid use during buprenorphine dose-tapering. METHODS: Regular heroin users not currently seeking treatment (n = 54; 29 current injectors, 25 non-injectors) were stabilized on 8-mg/day sublingual buprenorphine and assessed for subjective responses (e.g. 'liking', craving) to hydromorphone 24-mg intramuscular challenge (administered 16-hr post-buprenorphine) under randomized, double-blinded, controlled conditions. A subgroup (n = 35) subsequently completed a standardized 3-week outpatient buprenorphine dose-taper, paired with opioid-abstinent contingent reinforcement, and were assessed for return to opioid use based on thrice-weekly urinalysis and self-report. RESULTS: During buprenorphine stabilization, IDU reported lower 'liking' of buprenorphine and post-hydromorphone peak 'liking', 'good effect' and 'high' compared to non-IDU. Less hydromorphone peak increase-from-baseline in 'liking' (which correlated with less hydromorphone-induced craving suppression) predicted significantly faster return to opioid use during buprenorphine dose-tapering. CONCLUSIONS: In these buprenorphine-stabilized regular heroin users, IDU is associated with attenuated 'liking' response (more cross-tolerance) to buprenorphine and to high-dose hydromorphone challenge and, in turn, this cross-tolerance (but not IDU) predicts faster return to opioid use. Further research should examine mechanisms that link cross-tolerance to treatment response.

Medical and genetic correlates of long-term buprenorphine treatment in the electronic health records.

Despite the benefits associated with longer buprenorphine treatment duration (i.e., >180 days) (BTD) for opioid use disorder (OUD), retention remains poor. Research on the impact of co-occurring psychiatric issues on BTD has yielded mixed results. It is also unknown whether the genetic risk in the form of polygenic scores (PGS) for OUD and other comorbid conditions, including problematic alcohol use (PAU) are associated with BTD. We tested the association between somatic and psychiatric comorbidities and long BTD and determined whether PGS for OUD-related conditions was associated with BTD. The study included 6686 individuals with a buprenorphine prescription that lasted for less than 6 months (short-BTD) and 1282 individuals with a buprenorphine prescription that lasted for at least 6 months (long-BTD). Recorded diagnosis of substance addiction and disorders (Odds Ratio (95% CI) = 22.14 (21.88-22.41), P = 2.8 × 10-116), tobacco use disorder (OR (95% CI) = 23.4 (23.13-23.68), P = 4.5 × 10-111), and bipolar disorder (OR(95% CI) = 9.70 (9.48-9.92), P = 1.3 × 10-91), among others, were associated with longer BTD. The PGS of OUD and several OUD co-morbid conditions were associated with any buprenorphine prescription. A higher PGS for OUD (OR per SD increase in PGS (95%CI) = 1.43(1.16-1.77), P = 0.0009), loneliness (OR(95% CI) = 1.39(1.13-1.72), P = 0.002), problematic alcohol use (OR(95%CI) = 1.47(1.19-1.83), P = 0.0004), and externalizing disorders (OR(95%CI) = 1.52(1.23 to 1.89), P = 0.0001) was significantly associated with long-BTD. Associations between BTD and the PGS of depression, chronic pain, nicotine dependence, cannabis use disorder, and bipolar disorder did not survive correction for multiple testing. Longer BTD is associated with diagnoses of psychiatric and somatic conditions in the EHR, as is the genetic score for OUD, loneliness, problematic alcohol use, and externalizing disorders.

First Trimester Use of Buprenorphine or Methadone and the Risk of Congenital Malformations.

Importance: Use of buprenorphine or methadone to treat opioid use disorder is recommended in pregnancy; however, their teratogenic potential is largely unknown. Objective: To compare the risk of congenital malformations following in utero exposure to buprenorphine vs methadone. Design, Setting, and Participants: This population-based cohort study used health care utilization data from publicly insured Medicaid beneficiaries in the US from 2000 to 2018. A total of 13 360 pregnancies with enrollment from 90 days prior to pregnancy start through 1 month after delivery and first trimester use of buprenorphine or methadone were included and linked to infants. Data were analyzed from July to December 2022. Exposure: A pharmacy dispensing of buprenorphine or a code for administration of methadone in the first trimester. Main Outcomes and Measures: Primary outcomes included major malformations overall and malformations previously associated with opioids (any cardiac malformations, ventricular septal defect, secundum atrial septal defect/nonprematurity-related patent foramen ovale, neural tube defects, clubfoot, and oral clefts). Secondary outcomes included other organ system-specific malformations. Risk differences and risk ratios (RRs) were estimated comparing buprenorphine with methadone, adjusting for confounders with propensity score overlap weights. Results: The cohort included 9514 pregnancies with first-trimester buprenorphine exposure (mean [SD] maternal age, 28.4 [4.6] years) and 3846 with methadone exposure (mean [SD] maternal age, 28.8 [4.7] years). The risk of malformations overall was 50.9 (95% CI, 46.5-55.3) per 1000 pregnancies for buprenorphine and 60.6 (95% CI, 53.0-68.1) per 1000 pregnancies for methadone. After confounding adjustment, buprenorphine was associated with a lower risk of malformations compared with methadone (RR, 0.82; 95% CI, 0.69-0.97). Risk was lower with buprenorphine for cardiac malformations (RR, 0.63; 95% CI, 0.47-0.85), including both ventricular septal defect (RR, 0.62; 95% CI, 0.39-0.98) and secundum atrial septal defect/nonprematurity-related patent foramen ovale (RR, 0.54; 95% CI, 0.30-0.97), oral clefts (RR, 0.65; 95% CI, 0.35-1.19), and clubfoot (RR, 0.55; 95% CI, 0.32-0.94). Results for neural tube defects were uncertain given low event counts. In secondary analyses, buprenorphine was associated with a decreased risk of central nervous system, urinary, and limb malformations but a greater risk of gastrointestinal malformations compared with methadone. These findings were consistent in sensitivity and bias analyses. Conclusions and Relevance: In this cohort study, the risk of most malformations previously associated with opioid exposure was lower in buprenorphine-exposed infants compared with methadone-exposed infants, independent of measured confounders. Malformation risk is one factor that informs the individualized patient decision regarding medications for opioid use disorder in pregnancy.

Negative Urgency Linked to Craving and Substance Use Among Adults on Buprenorphine or Methadone.

Despite the effectiveness of medication-assisted treatment (MAT), adults receiving MAT experience opioid cravings and engage in non-opioid illicit substance use that increases the risk of relapse and overdose. The current study examines whether negative urgency, defined as the tendency to act impulsively in response to intense negative emotion, is a risk factor for opioid cravings and non-opioid illicit substance use. Fifty-eight adults (predominately White cis-gender females) receiving MAT (with buprenorphine or methadone) were recruited from online substance use forums and asked to complete self-report questionnaires on negative urgency (UPPS-P Impulsive Behavior Scale), past 3-month opioid cravings (ASSIST-Alcohol, Smoking, and Substance Involvement Screening Test), and non-opioid illicit substance use (e.g., amphetamines, cocaine, benzodiazepines). Results revealed that negative urgency was associated with past 3-month opioid cravings, as well as past month illicit stimulant use (not benzodiazepine use). These results may indicate that individuals high in negative urgency would benefit from receiving extra intervention during MAT.

Clinical efficacy of buprenorphine after oral dosing in rats undergoing major surgery.

Serum corticosterone, serum buprenorphine, body weight change, consumption of food and water and behaviour-based pain assessment were measured in catheterised and non-catheterised male Wistar rats undergoing myocardial infarct (MI) surgery under general anaesthesia following buprenorphine dosing by subcutaneous (Bup-SC, 0.05 mg/kg) and oral (Bup-O, 0.4 mg/kg) routes. Buprenorphine was dosed subcutaneously at half an hour before and 8, 16 and 24 hours after surgery (Bup-SC), orally at one hour before surgery (Bup-O1) or at one hour before and 12 hours after surgery (Bup-O2) in catheterised rats and at one hour before and 24 hours after surgery (Bup-O24) in non-catheterised rats. Serum corticosterone, body weight changes and food and water consumption were not significantly different between treatments in catheterised rats. Bup-SC resulted in rapidly decreasing serum concentrations below the clinically effective concentrations (1 ng/mL) already at two hours after the first dose. Bup-O provided significantly higher and slowly decreasing serum concentrations, at or above clinically effective concentrations, for 24 hours (Bup-O1) and 42 hours (Bup-O2) after surgery. In non-catheterised rats, body weight development and food consumption were significantly higher in Bup-O24 rats compared to Bup-SC rats. The results indicate that a SC buprenorphine dose of 0.05 mg/kg every eight hours provides long periods of serum concentrations below clinically effective levels, and that a higher dose and/or more frequent dosage are required to provide stable serum concentrations at or above clinically effective levels. A single oral buprenorphine dose of 0.4 mg/kg provides clinically effective and stable serum concentrations for 24 hours in rats after MI surgery.

Pain Management in Patients With Opioid Use Disorder on Extended-release Buprenorphine: A Case Report.

ABSTRACT: Persons with opioid use disorder (OUD) are receiving extended-release buprenorphine (ER-buprenorphine) for treatment of OUD. There are no clinical guidelines for management of patients with OUD on ER-buprenorphine experiencing acute or chronic pain. This case report describes 3 patient-involved, multidisciplinary approaches for pain management in various clinical scenarios, including a scheduled knee replacement, emergent surgery for an ischemic limb, and management of chronic pain from metastatic malignancy. These cases illustrate that adequate analgesia for patients who have received ER-buprenorphine is possible, and approaches can be individualized, with shared decision making between providers and patients addressing all barriers to optimize treatment outcomes. Options for acute pain management that can be considered include supplemental sublingual buprenorphine, nonopioid adjuncts, and short courses of full opioid agonists. Potential barriers that impact OUD and acute/chronic pain are provider bias, limited access to palliative care clinicians with addiction medicine training, and payor restrictions to adding sublingual buprenorphine for patients that are on ER-buprenorphine. Additional training for clinicians and other members of the health care team is recommended to improve patient-involved care of persons with OUD experiencing pain.

Effects of live-online, group mindfulness training on opioid use and anxiety during buprenorphine treatment: A comparative effectiveness RCT.

BACKGROUND: Office-based opioid treatment with buprenorphine has emerged as a popular evidence-based treatment for opioid use disorder. Unfortunately, psychosocial stress, anxiety, pain, and co-morbid substance use increase patients' risk for relapse. We designed this study to compare the effects of complementing buprenorphine treatment with 24 weeks of a live-online Mindful Recovery Opioid Care Continuum (M-ROCC) group to a time and attention-matched, live-online Recovery Support Group (RSG) active control condition. METHODS: We plan to enroll a maximum of N = 280 and randomize at least N = 192 patients prescribed buprenorphine through referrals from office-based and telemedicine buprenorphine treatment providers and social media advertisements. Participants will be randomly assigned to M-ROCC or RSG and will be blinded to their treatment condition. The primary outcome for this study will be biochemically confirmed periods of abstinence from illicit opioids, as measured by self-reported use and randomly collected, video-observed oral fluid toxicology testing during the final 12 weeks of study participation. Secondary outcomes include changes in Patient-Reported Outcomes Measurement Information System (PROMIS) anxiety and pain interference scores between baseline and week 24. RESULTS: The trial was funded by the National Institutes of Health, HEAL Initiative through NCCIH (R33AT010125). Data collection is projected to end by September 2023, and we expect publication of results in 2024. CONCLUSION: If the M-ROCC intervention is found to be effective in this format, it will demonstrate that live-online mindfulness groups can improve outcomes and address common co-morbidities like anxiety and pain during buprenorphine treatment.

Quality of life and associated factors of heroin-dependent patients receiving methadone and buprenorphine maintenance treatment.

AIM: Although studies in Western countries have investigated the quality of life (QoL) of heroin users, limited research on this topic has been conducted in Asia. The present study assessed QoL in patients with heroin dependence receiving medications to treat opioid use disorder. METHODS: We performed a cross-sectional study of patients with heroin dependence receiving methadone and buprenorphine treatment. The demographic and substance use variables of patients receiving methadone and buprenorphine were compared. The Chinese Health Questionnaire (CHQ-12), Obsessive Compulsive Drug Use Scale (OCDUS), and World Health Organization Quality of Life Short Form Taiwan version (WHOQOL-BREF-T) were administered to measure patient mental health problems, addiction severity, and QoL, respectively. Multivariate regression was used to identify the factors associated with QoL. RESULTS: A total of 149 patients receiving methadone and 31 receiving buprenorphine completed the questionnaires. Individuals in the buprenorphine group were more likely to be married (p = 0.024) or employed (p = 0.024), have a higher educational level (p = 0.013), have lower drug craving (OCDUS: p = 0.035), or have higher QoL (WHOQOL-BREF-T: p = 0.004) than those in the methadone group. After adjustment for other variables, employment was positively associated with the physical, psychological, and environmental domains of QoL. Receiving buprenorphine treatment (p = 0.032) and longer treatment duration (p = 0.016) were associated with higher psychological QoL. CONCLUSION: Several factors were associated with QoL in patients with heroin dependence. Some measures may improve their QoL, such as reducing employment barriers, improving treatment adherence, or increasing accessibility to buprenorphine treatment.

Effect of transversus abdominis plane block with or without buprenorphine after inguinal hernia surgery on postoperative pain.

INTRODUCTION: Transversus abdominis plane (TAP) has been mentioned as having bene-ficial effects on chronic pain after hernioplasty. This study assessed the effects of TAP block on acute and persistent postoperative pain after inguinal hernia surgery, with or without buprenorphine. MATERIAL AND METHODS: 64 patients were allocated to group R ( n = 32) and received 20 mL of 0.25% ropivacaine for TAP block; group RB ( n = 32) received 20 mL of 0.25% ropivacaine containing 300 µg of buprenorphine for TAP block. The primary outcome was the analgesic and antihyperalgesic effect of buprenorphine. The duration of analgesia, analgesic consumption, postoperative pain scores at rest and sitting up to 48 hours, and the effect on wound hyperalgesia were evaluated. Secondary outcomes included the incidence of side effects and complications. RESULTS: The median (IQR) duration of analgesia in group R was 386.5 (37.25) minutes vs. 868 (41.3) minutes in the RB group. Median pain scores on sitting were found to be significantly better in group RB than in group R at 6, 12, and 24 hours ( P < 0.001). The wound hyperalgesia index showed a significant difference between groups ( P < 0.001). The incidence of persistent postoperative pain was 6.25% in the R group, as compared to 0% in the RB group. Otherwise, the patients did not have any further complications associated with the block. CONCLUSIONS: The results demonstrated that TAP block with buprenorphine reduced acute postoperative pain severity, but we did not find a difference between groups in persistent pain.

Comparing Three Formulations of Buprenorphine in an Incisional Pain Model in Mice.

This study compared the therapeutic effects in mice of 3 different formulations of buprenorphine. These formulations were standard buprenorphine hydrochloride (Bup-HCL) and 2 different extended-release buprenorphine formulations (Bup-ER and Ethiqa-XR [Bup-XR]). Drugs were evaluated based on their ability to attenuate thermal hypersensitivity in a mouse plantar incisional pain model. We hypothesized that Bup-HCL would attenuate postoperative thermal hypersensitivity at 20 min after administration, and that Bup-ER and Bup-XR would attenuate thermal hypersensitivity at 40 min after administration. Male C57BL6/J mice were randomly assigned to 1 of 4 treatment groups: 1) saline, 5 mL/kg SC, once; 2) Bup-HCL, 0.1 mg/kg SC, once; 3) Bup-ER, 1 mg/kg, SC, once; and 4) Bup-XR, 3.25 mg/kg, SC, once. Thermal hypersensitivity was assessed on the day before surgery and again on the day of surgery at 20, 40, 60, 90, and 120 min after drug administration. Thermal hypersensitivity after surgery was not different among the Bup-HCL, Bup-ER and Bup-XR groups at any timepoint. In addition, all buprenorphine treatment groups showed significantly less thermal hypersensitivity after surgery than did the saline group. Subjective observations suggested that mice that received Bup-ER or Bup-XR became hyperactive after drug administration (83 and 75% of mice tested, respectively). Our results indicate that Bup-HCL, Bup-ER, or Bup-XR attenuate thermal hyper- sensitivity related to foot incision by 20 min after administration.

Current State of Perioperative Buprenorphine Management-A National Provider Survey.

OBJECTIVES: Buprenorphine maintenance for opioid use disorder (OUD) can present potential challenges for acute postoperative pain management. Provider practice and consistency of buprenorphine management strategies within institutions are unknown. This study aims to identify how providers nationwide manage patients on buprenorphine when they present for elective surgery. METHODS: A prospective survey of anesthesiologists was performed nationwide between November 2021 and March 2022. Survey respondents were selected from academic institutions identified using public databases and were also distributed to online social media platforms where members are required to verify medical licensure and hospital affiliation. Survey results were calculated and interpreted as the percentage rate of response. RESULTS: Survey invitations were sent to 190 institutions and returned 54 responses (28% response rate). An additional 12 completed surveys were obtained from online social media distribution resulting in 66 responses. Only 36% of respondents reported an established protocol for perioperative management of buprenorphine at their institution. Regarding consistency of buprenorphine management within institutions, the majority of respondents endorsed buprenorphine continuation without dose reduction in procedures where minimal pain was anticipated. However, there was a large discrepancy in buprenorphine management for surgeries with moderate-severe pain. Perioperative dosing frequency of buprenorphine was also inconsistent. CONCLUSIONS: The majority of institutions surveyed do not have an established protocol for perioperative buprenorphine management. In addition, there is provider variability in buprenorphine dosing for procedures with moderate-severe pain. This study highlights the need for dissemination of consensus guidelines for buprenorphine management.

Postpartum Extended-Release Buprenorphine Tissue Necrosis.

BACKGROUND: Extended-release buprenorphine (XRB) may improve medication for opioid use disorder continuation among postpartum individuals. However, obstetric clinicians have relatively little experience with XRB. We describe two cases of XRB-related tissue necrosis in postpartum individuals to highlight recommended injection technique and management strategies for this rare complication. CASES: One patient developed tissue necrosis after her initial injection. Her wound was expectantly managed. Another patient on long-term XRB developed tissue necrosis within 1 day of injection. General surgery excised the depot. Both instances were attributed to injection of XRB intradermally rather than subcutaneously. Both patients continued monthly XRB without recurrence, suggesting that this complication is not an allergy. CONCLUSION: Clinicians should be able to prevent, recognize, and manage tissue necrosis, a rare complication of XRB injection.

A Case of Acute Opioid Withdrawal after Liposuction Surgery in a Patient on Extended-release Buprenorphine.

BACKGROUND: The US Food and Drug Administration approved the once-monthly injectable extended-release buprenorphine product to treat moderate-to-severe opioid use disorders. The patient in our case report had a liposuction procedure and immediately started having opioid withdrawal symptoms after the procedure. CASE DESCRIPTION: The patient is a 27-year-old African-American woman who injects drugs and has morbid obesity. She enrolled in a medications for addiction treatment program and opted to get treated with extended-release buprenorphine monthly injections. She tolerated them well for a span of 6 months. In one clinic visit, she reported opioid withdrawal symptoms and started purchasing and using sublingual buprenorphine from her acquaintances. On review of history, she underwent liposuction surgery and this triggered the opioid withdrawal symptoms. Examining her abdomen revealed surgical scars at the site of the buprenorphine injection and the residual buprenorphine depot was not palpable.A subcutaneous injection of 300-mg extended release buprenorphine was administered in the right periumbilical area in this clinic visit. The following week, she was doing well and denied any withdrawal symptoms. DISCUSSION: This is a unique case of "iatrogenic opioid withdrawal" after a fairly common surgical procedure. The extended-release buprenorphine formulation solidifies when it comes into contact with bodily fluids forming a depot. The depot and surrounding adipose tissue may have been removed during the patient's liposuction procedure, causing an immediate drop in buprenorphine levels leading to acute opioid withdrawal.This case report highlights the precautions that need to be taken before patients go for a surgical procedure like liposuction.

Buprenorphine plasma and cerebrospinal fluid concentrations in osteoarthritis patients during low-dose transdermal patch dosing.

METHODS: Fifty-six (56) patients scheduled for arthroplasty, received 7-day extended-release buprenorphine transdermal patches (5 µg/h) for five consecutive weeks, starting two weeks prior to the surgery. Simultaneous plasma and cerebrospinal fluid (CSF) samples were collected during spinal anesthesia. RESULTS: Median buprenorphine plasma and CSF concentrations at steady-state were 54 pg/mL (range 8.6 - 167 pg/mL) and 1.6 pg/mL (0.30 - 7.3 pg/mL), respectively. The median CSF/plasma -ratio was 3% (range 0.35 - 16%). Large between-subject variability was observed in the measured buprenorphine concentrations within the study population.

Pharmacokinetics of Extended-release Buprenorphine in Mongolian Gerbils (Meriones unguiculatus).

Both the Guide for the Care and Use of Laboratory Animals and the Animal Welfare Act and Regulations require animals in research to receive adequate analgesia unless an exception can be scientifically justified and IACUC approved. Extended- release buprenorphine (BUP-XR) is a pharmaceutical-grade formulation that is FDA-indexed for use in mice and rats. However, this new formulation has not been evaluated in adult Mongolian gerbils (Meriones unguiculatus). Our goal was to determine whether the extrapolated dose (1 mg/kg SC) would achieve plasma buprenorphine concentrations above the murine therapeutic threshold (> 1.0 ng/mL) in male and female gerbils. We hypothesized that BUP-XR administered at 1 mg/kg would achieve the murine therapeutic threshold in both male and female gerbils until at least 48 h after injection. Gerbils received one injection of BUP-XR (1 mg/kg SC) and underwent 4 serial blood collections (0.5, 1, 2, and 4, or 0.5, 24, 48, and 72 h after injection). The average plasma buprenorphine concentrations were above 1 ng/mL within 30 min of administration for both males and females. Plasma buprenorphine concentrations remained above 1.0 ng/mL for 48 h after administration. In males, plasma buprenorphine concentrations were significantly higher at 1 h after injection as compared with females; no other significant differences were observed between sexes. Mild to moderate injection-site granulomas were observed in five of nine gerbils, presumably due to the lipid matrix of the BUP-XR formulation. Our findings demonstrate that a single BUP-XR dose (1 mg/kg SC) achieves plasma buprenorphine levels that remain above the murine therapeutic threshold of 1.0 ng/mL for up to 48 h in both sexes.

Expert consensus-based guidance on approaches to opioid management in individuals with advanced cancer-related pain and nonmedical stimulant use.

BACKGROUND: Clinicians treating cancer-related pain with opioids regularly encounter nonmedical stimulant use (i.e., methamphetamine, cocaine), yet there is little evidence-based management guidance. The aim of the study is to identify expert consensus on opioid management strategies for an individual with advanced cancer and cancer-related pain with nonmedical stimulant use according to prognosis. METHODS: The authors conducted two modified Delphi panels with palliative care and addiction experts. In Panel A, the patient's prognosis was weeks to months and in Panel B the prognosis was months to years. Experts reviewed, rated, and commented on the case using a 9-point Likert scale from 1 (very inappropriate) to 9 (very appropriate) and explained their responses. The authors applied the three-step analytical approach outlined in the RAND/UCLA to determine consensus and level of clinical appropriateness of management strategies. To better conceptualize the quantitative results, they thematically analyzed and coded participant comments. RESULTS: Consensus was achieved for all management strategies. The 120 Experts were mostly women (47 [62%]), White (94 [78%]), and physicians (115 [96%]). For a patient with cancer-related and nonmedical stimulant use, regardless of prognosis, it was deemed appropriate to continue opioids, increase monitoring, and avoid opioid tapering. Buprenorphine/naloxone transition was inappropriate for a patient with a short prognosis and of uncertain appropriateness for a patient with a longer prognosis. CONCLUSION: Study findings provide urgently needed consensus-based guidance for clinicians managing cancer-related pain in the context of stimulant use and highlight a critical need to develop management strategies to address stimulant use disorder in people with cancer. PLAIN LANGUAGE SUMMARY: Among palliative care and addiction experts, regardless of prognosis, it was deemed appropriate to continue opioids, increase monitoring, and avoid opioid tapering in the context of cancer-related pain and nonmedical stimulant use. Buprenorphine/naloxone transition as a harm reduction measure was inappropriate for a patient with a short prognosis and of uncertain appropriateness for a patient with a longer prognosis.