Kappa-opioid receptor antagonism in the nucleus accumbens shell distinguishes escalated alcohol consumption and negative affective-like behavior from physiological withdrawal in alcohol-dependence

Alcohol use disorder (AUD) is a chronic relapsing disease that is deleterious at individual, familial, and societal levels. Although AUD is one of the highest preventable causes of death in the USA, therapies for the treatment of AUD are not sufficient given the heterogeneity of the disorder and the limited number of approved medications. To provide better pharmacological strategies, it is important to understand the neurological underpinnings of AUD. Evidence implicates the endogenous dynorphin (DYN)/κ-opioid receptor (KOR) system recruitment in dysphoric and negative emotional states in AUD to promote maladaptive behavioral regulation. The nucleus accumbens shell (AcbSh), mediating motivational and emotional processes that is a component of the mesolimbic dopamine system and the extended amygdala, is an important site related to alcohol's reinforcing actions (both positive and negative) and neuroadaptations in the AcbSh DYN/KOR system have been documented to induce maladaptive symptoms in AUD. We have previously shown that in other nodes of the extended amygdala, site-specific KOR antagonism can distinguish different symptoms of alcohol dependence and withdrawal. In the current study, we examined the role of the KOR signaling in the AcbSh of male Wistar rats in operant alcohol self-administration, measures of negative affective-like behavior, and physiological symptoms during acute alcohol withdrawal in alcohol-dependence. To induce alcohol dependence, rats were exposed to chronic intermittent ethanol vapor for 14 h/day for three months, during which stable escalation of alcohol self-administration was achieved and pharmacological AcbSh KOR antagonism ensued. The results showed that AcbSh KOR antagonism significantly reduced escalated alcohol intake and negative affective-like states but did not alter somatic symptoms of withdrawal. Understanding the relative contribution of these different drivers is important to understand and inform therapeutic efficacy approaches in alcohol dependence and further emphasis the importance of the KOR/DYN system as a target for AUD therapeutics.

Negative allosteric modulation of CB1 cannabinoid receptor signaling suppresses opioid-mediated tolerance and withdrawal without blocking opioid antinociception

The direct blockade of CB1 cannabinoid receptors produces therapeutic effects as well as adverse side-effects that limit their clinical potential. CB1 negative allosteric modulators (NAMs) represent an indirect approach to decrease the affinity and/or efficacy of orthosteric cannabinoid ligands or endocannabinoids at CB1. We recently reported that GAT358, a CB1-NAM, blocked opioid-induced mesocorticolimbic dopamine release and reward via a CB1-allosteric mechanism of action. Whether a CB1-NAM dampens opioid-mediated therapeutic effects such as analgesia or alters other unwanted opioid side-effects remain unknown. Here, we characterized the effects of GAT358 on nociceptive behaviors in the presence and absence of morphine in male rats. We examined the impact of GAT358 on formalin-evoked pain behavior and Fos protein expression, a marker of neuronal activation, in the lumbar spinal cord. We also assessed the impact of GAT358 on morphine-induced slowing of colonic transit, tolerance, and withdrawal behaviors in male mice. GAT358 attenuated morphine antinociceptive tolerance without blocking acute antinociception and reduced morphine-induced slowing of colonic motility without impacting fecal boli production. GAT358 also produced antinociception in the presence and absence of morphine in the formalin model of inflammatory nociception and reduced the number of formalin-evoked Fos protein-like immunoreactive cells in the lumbar spinal cord. Finally, GAT358 mitigated the somatic signs of naloxone-precipitated, but not spontaneous, opioid withdrawal following chronic morphine dosing. Our results support the therapeutic potential of CB1-NAMs as novel drug candidates aimed at preserving opioid-mediated analgesia while preventing their unwanted side-effects. Our studies also uncover previously unrecognized antinociceptive properties associated with an arrestin-biased CB1-NAM.

Phenobarbital Versus Benzodiazepines for the Treatment of Severe Alcohol Withdrawal

BACKGROUND

Phenobarbital may offer advantages over benzodiazepines for severe alcohol withdrawal syndrome (SAWS), but its impact on clinical outcomes has not been fully elucidated.

OBJECTIVE

The purpose of this study was to determine the clinical impact of phenobarbital versus benzodiazepines for SAWS.

METHODS

This retrospective cohort study compared phenobarbital to benzodiazepines for the management of SAWS for patients admitted to progressive or intensive care units (ICUs) between July 2018 and July 2022. Patients included had a history of delirium tremens (DT) or seizures, Clinical Institute Withdrawal Assessment of Alcohol-Revised (CIWA-Ar) >15, or Prediction of Alcohol Withdrawal Severity Scale (PAWSS) score ≥4. The primary outcome was hospital length of stay (LOS). Secondary outcomes included progressive or ICU LOS, incidence of adjunctive pharmacotherapy, and incidence/duration of mechanical ventilation.

RESULTS

The final analysis included 126 phenobarbital and 98 benzodiazepine encounters. Patients treated with phenobarbital had shorter median hospital LOS versus those treated with benzodiazepines (2.8 vs 4.7 days; P < 0.0001); a finding corroborated by multivariable analysis. The phenobarbital group also had shorter median progressive/ICU LOS (0.7 vs 1.3 days; P < 0.0001), and lower incidence of dexmedetomidine (P < 0.0001) and antipsychotic initiation (P < 0.0001). Fewer patients in the phenobarbital group compared to the benzodiazepine group received new mechanical ventilation (P = 0.045), but median duration was similar (1.2 vs 1.6 days; P = 1.00).

CONCLUSION AND RELEVANCE

Scheduled phenobarbital was associated with decreased hospital LOS compared to benzodiazepines for SAWS. This was the first study to compare outcomes of fixed-dose, nonoverlapping phenobarbital to benzodiazepines in patients with clearly defined SAWS and details a readily implementable protocol.

Impact of an alcohol withdrawal screening and treatment protocol for hospitalized patients

INTRODUCTION

Alcohol Withdrawal Syndrome (AWS) is a potentially life-threatening complication of alcohol use disorder (AUD) that can be challenging to recognize in hospitalized patients. Our institution implemented universal AUD screening for all patients admitted to a non-critical care venue using the Prediction of Alcohol Withdrawal Severity Scale (PAWSS). At risk patients were then further assessed, utilizing the Glasgow Modified Alcohol Withdrawal Scale (GMAWS), and medicated according to a predetermined protocol. This study sought to determine whether this protocol decreased hospital length of stay, lowered the total benzodiazepine dose administered, and decreased adverse events attributable to AWS.

METHODS

This retrospective cohort study was conducted over a 6-year period from 2014 to 2020. The study included patients with an ICD-10 code diagnosis of AWS and subsequently divided them into two groups: pre- and post-protocol introduction. Outcome measures were compared pre- versus post-protocol introduction.

RESULTS

There were 181 patient encounters pre- and 265 patient encounters post-protocol. There was no statistically significant difference in median length of stay between the two groups (2.956 days pre and 3.250 days post-protocol, p = 0.058). Post-protocol, there was a statistically significant reduction in median total benzodiazepine dose (13.5 mg and 9 mg lorazepam equivalents pre- and post-protocol, p < 0.001) and in occurrence of delirium tremens (7.7 % pre and 2.3 % post-protocol, p = 0.006).

CONCLUSION

Protocol implementation did not reduce length of stay in patients with AUD but was associated with a significant reduction in total benzodiazepine dose and, when adjusted, a non-statistically significant decrease in progression to delirium tremens in hospitalized patients, after applying Bonferroni adjustment.

Impact of a Divided Phenobarbital Load and Taper Compared With Lorazepam Symptom Triggered Therapy in Hospitalized Patients

BACKGROUND

Benzodiazepines are the preferred treatment for alcohol withdrawal. Phenobarbital is an alternative in the setting of prescriber expertise or benzodiazepine contraindication.

OBJECTIVE

To evaluate the efficacy and safety of a phenobarbital dosing strategy aimed at treating a spectrum of alcohol withdrawal symptoms across various patient populations.

METHODS

Retrospective review of patients admitted with concerns of alcohol withdrawal between May 2018 and November 2022. Patients were separated into a before-after cohort of lorazepam or phenobarbital. The primary outcome was hospital length of stay (LOS). Secondary outcomes were intensive care unit (ICU) LOS, escalation of respiratory support, increased level of care (LOC), and incidence of delirium tremens and/or seizures.

RESULTS

Two hundred and seventy-seven patients received lorazepam and 198 received phenobarbital. Hospital LOS was longer in the phenobarbital cohort compared with the lorazepam cohort (6.9 vs 9.3 days). There was no difference in ICU LOS. Level of care increases were fewer in the phenobarbital cohort (4 events vs 19 events). There were higher rates of non-invasive respiratory interventions in the lorazepam cohort and higher rates of mechanical ventilation in the phenobarbital cohort. Utilization of phenobarbital was attributed to a reduction in delirium tremens and seizures.

CONCLUSION AND RELEVANCE

This study is novel because of the broad application of a phenobarbital order set across multiple levels of care and patient admission diagnoses. A risk targeted split load intravenous phenobarbital order set can safely be administered to patients with fewer escalations of care, seizures, delirium tremens, and respiratory care escalation.

The Effect of Antidepressants on Withdrawal in Patients with Alcohol Dependence: A Retrospective Study

The use of electronic health records has expanded in the past decades, with healthcare entities storing terabytes of patient health data. In this study, we investigated how these databases can be utilized to generate clinically relevant information. We used the Office of Addiction Services and Supports Client Data Systems data merged with the NYS Medicaid Data Warehouse to study the relationship of certain antidepressants on alcohol withdrawal (AW) rates in patients with alcohol dependence (AD). We found that in patients with AD, bupropion was associated with a significantly reduced rate of AW compared to selective serotonin reuptake inhibitors (SSRIs). This may be due to the ability of bupropion to inhibit dopaminergic reuptake. This retrospective study provides the advantage of being faster and less expensive than randomized controlled trials (RCTs).

Use of sodium oxybate for the treatment of alcohol withdrawal syndrome in patients with acute alcohol-associated hepatitis: A 4-patient case report

INTRODUCTION

During the treatment of alcohol use disorder, alcohol withdrawal syndrome (AWS) can occur. Benzodiazepines remain the "gold standard" for the pharmacological treatment of AWS. However, other drugs have been approved in some European Countries for the treatment of AWS: namely, clomethiazole in Spain and Germany and sodium oxybate in Italy and Austria. Acute alcohol-associated hepatitis (AAH) is a distinct clinical syndrome characterized by the recent onset of jaundice with or without other signs of liver decompensation in patients with ongoing alcohol consumption.

RATIONALE

We report 4 paradigmatic clinical cases to analyze the efficacy, safety, and tolerability of the very short half-life (30-45 minutes) sodium oxybate (SO) in the management of AWS with moderate to severe AAH. Compared to SO, "as needed" short-acting benzodiazepines, currently prescribed to treat AWS in patients with AAH, have a much longer half-life (5-25 hours) which increases the risk of drug accumulation. The very short half-life of SO provides a fixed dose approach allowing for a more effective control of AWS than "as needed" therapy throughout the 24 hours.

PATIENT CONCERNS

Patients reported anxiety, agitation, diffuse abdominal pain, loss of appetite, and nausea with elevation in serum bilirubin and 2 of them had abdomen distension due to ascites.

DIAGNOSIS

Patients were affected by moderate or severe AWS and moderate or severe AAH on alcohol-related liver cirrhosis.

INTERVENTIONS

In order to suppress AWS, all patients were treated with oral sodium oxybate at a dose of 25 mg/kg/day, progressively increased to 50 to 100 mg/kg/day, divided into 3 to 5 administrations.

OUTCOMES

SO was efficient, safe and tolerable in suppressing AWS even in patients with severe AAH. All treated patients showed a rapid improvement of all symptom (via the Clinical Institute of Withdrawal Assessment for Alcohol Scale) and liver test scores (Model for End-Stage Liver Disease).

CONCLUSION

Because of its short half-life, SO can be considered a safe and effective pharmacological option for the AWS in patients with moderate to severe AAH even in comparison to short-acting benzodiazepines, thus avoiding the risk of accumulation. Notably, SO guarantees a fixed approach to cover the possible onset of AWS throughout the 24 hours.

Assessing predictors of adequate individual buprenorphine maintenance dosage for the treatment of opioid use disorder: Listening to the patient

OBJECTIVE

Dose optimization plays a key role in determining clinical outcomes in patients on opioid agonist treatment (OAT). The objective of this study was to identify the variables independently associated with buprenorphine/naloxone (B/N) dose adequacy in patients with opiate use disorder (OUD).

METHOD

Cross-sectional study of a convenience sample of patients with OUD treated with B/N (n = 315) in four regions in Spain. The Opiate Dosage Adequacy Scale (ODAS) was used to determine B/N dose adequacy. The ODAS evaluate the six components of the "dose adequacy" construct, as follows: continued use of heroin; narcotic blockade or crossed tolerance; objective opioid withdrawal symptoms (OWS); subjective OWS; craving for heroin; and overmedication. A binomial logistic regression analysis was performed to identify the variables associated with the condition "ODAS Adequate B/N dose". Participants completed a battery of instruments to assess sociodemographic, substance use, clinical, and treatment variables.

RESULTS

The B/N dose was considered adequate in 231 of the 315 participants (73.3 %). Two variables, satisfaction with B/N as a medication (OR=5.764, 95 % CI=2.211-15.030) and patient-perceived participation in B/N dose decisions (OR=1.790, 95 % CI=1221-2623), were independently, significantly, and positively associated with the "ODAS Adequate B/N dose" condition. While the severity of heroin dependence was significantly associated with buprenorphine dose adequacy in the bivariate analyses, significance was lost in the full regression model.

CONCLUSION

Satisfaction with B/N as a medication and patient-perceived involvement in the dose decision are associated with clinician-assessed dose adequacy. In the context of good clinical practice, it is important to take into account both of these variables to individualize the prescribed dose through a shared decision-making process.

Effects of CB1 receptor negative allosteric modulator Org27569 on oxycodone withdrawal symptoms in mice

RATIONALE/OBJECTIVES

Targeting cannabinoid receptor type 1 (CB1R) has shown promise for treating opioid withdrawal symptoms. This study aimed to investigate the efficacy of a specific CB1R negative allosteric modulator (NAM), Org27569, in reducing both naloxone-precipitated and protracted withdrawal symptoms in oxycodone-dependent mice.

METHODS

Mice received escalating doses of oxycodone (9-33 mg/kg IP) or saline twice daily for 9 days, followed by a final dose of oxycodone (33 mg/kg) or saline in the morning of day 9. In one cohort, the impact of Org27569 (3, 10, and 30 mg/kg) on naloxone (10 mg/kg IP) precipitated withdrawal symptoms was assessed. In another cohort, Org27569 (3 mg/kg) effects on the acquisition of conditioned place aversion to naloxone (0.6 mg/kg) precipitated opioid withdrawal, on behaviour following a 7-9-day abstinence period, and on naloxone (0.6 mg/kg) precipitated withdrawal-induced escape behaviour in a novel assay were assessed.

RESULTS

Although Org27569 decreased opioid withdrawal-induced jumping at doses of 10 and 30 mg/kg, these effects were confounded by reduced locomotion. At all doses tested, Org27569 had a modest inhibitory effect on gastrointestinal motility. At the lower dose of 3 mg/kg, which was not confounded by locomotor effects, Org27569 did not impact naloxone-precipitated withdrawal-induced jumping, acquisition of oxycodone withdrawal-induced conditioned place aversion, or naloxone-precipitated withdrawal-induced escape behaviour in a novel assay. A clear protracted opioid withdrawal phenotype was not observed in assays of anxiety-like or social behaviour.

CONCLUSIONS

Org27569 effects on negative affective-like symptoms were confounded by locomotor effects and effects on gastrointestinal motility were not opioid withdrawal specific. Further studies are needed in a model that produces a more pronounced protracted withdrawal syndrome.

Cannabidiol Reduces Nicotine Withdrawal Severity and State Anxiety During an Acute E-cigarette Abstinence Period: A Novel, Open-Label Study

Introduction: Despite efforts to curb nicotine use, 8.1 million adults in the United States use e-cigarettes. Notably, the majority of nicotine-containing e-cigarette users report wanting to quit in the near future, yet there is a dearth of research surrounding intervention efforts. Cannabidiol (CBD) has potential to facilitate e-cigarette quit attempts by decreasing withdrawal symptom intensity and anxiety during nicotine e-cigarette abstinence. Methods: This study employed an open-label, crossover design (n=20) to test the hypothesis that among daily nicotine-containing e-cigarette users, oral administration of 320 mg CBD would reduce self-reported nicotine withdrawal severity and state anxiety following a 4-h e-cigarette abstinence period compared to withdrawal and anxiety reported after abstinence in the absence of CBD. Results: After controlling for participants' positive CBD expectancies, results were consistent with hypotheses, suggesting CBD reduced both nicotine withdrawal symptom severity and state anxiety during e-cigarette abstinence. Conclusion: These preliminary findings suggest testing the impact of CBD on e-cigarette cessation attempts is warranted.

A novel tramadol-polycaprolactone implant could palliate heroin conditioned place preference and withdrawal in rats: behavioral and neurochemical study

Drug dependence is a chronic brain disease characterized by craving and recurrent episodes of relapse. Tramadol HCl is a promising agent for withdrawal symptoms management, considering its relatively low abuse potential and safety. Oral administration, however, is not preferred in abstinence maintenance programs. Introducing an implantable, long-lasting formula is suggested to help outpatient abstinence programs achieve higher rates of treatment continuation. Tramadol implants (T350 and T650) were prepared on polycaprolactone polymer ribbons by the wet method. Male Wistar rats were adapted to heroin-conditioned place preference (CPP) at escalating doses (3-30 mg/kg, intraperitoneally, for 14 days). Implants were surgically implanted in the back skin of rats. After 14 days, the CPP score was recorded. Naloxone (1 mg/kg, intraperitoneally) was used to induce withdrawal on day 15, and symptoms were scored. Elevated plus maze and open field tests were performed for anxiety-related symptoms. Striata were analyzed for neurochemical changes reflected in dopamine, 3,4-dihydroxyphenyl acetic acid, gamma-aminobutyric acid, and serotonin levels. Brain oxidative changes including glutathione and lipid peroxides were assessed. The tramadol implants (T350 and T650) reduced heroin CPP and limited naloxone-induced withdrawal symptoms. The striata showed increased levels of 3,4-dihydroxyphenyl acetic acid, and serotonin and decreased levels of gamma-aminobutyric acid and dopamine after heroin withdrawal induction, which were reversed after implanting T350 and T650. Implants restore the brain oxidative state. Nonsignificant low naloxone-induced withdrawal score after the implant was used in naive subjects indicating low abuse potential of the implants. The presented tramadol implants were effective at diminishing heroin CPP and withdrawal in rats, suggesting further investigations for application in the management of opioid withdrawal.

Teneurin C-terminal associated peptide (TCAP)-1 attenuates the development and expression of naloxone-precipitated morphine withdrawal in male Swiss Webster mice

RATIONALE

Corticotropin-releasing factor (CRF), the apical stress-inducing hormone, exacerbates stress and addictive behaviors. TCAP-1 is a peptide that directly inhibits both CRF-mediated stress and addiction-related behaviors; however, the direct action of TCAP-1 on morphine withdrawal-associated behaviors has not previously been examined.

OBJECTIVE

To determine whether TCAP-1 administration attenuates behavioral and physiological consequences of morphine withdrawal in mice.

METHODS

Mice were administered via subcutaneous route TCAP-1 either before or after initial morphine exposure, after which jumping behavior was quantified to assess the effects of TCAP-1 on naloxone-precipitated morphine withdrawal. As a comparison, mice were treated with nonpeptide CRF1 receptor antagonist CP-154,526. In one experiment, plasma corticosterone (CORT) was also measured as a physiological stress indicator.

RESULTS

Pretreatment with TCAP-1 (10-250 nmol/kg) before morphine treatment significantly inhibited the development of naloxone-precipitated withdrawal. TCAP-1 (250-500 nmol/kg) treatment administered after morphine treatment attenuated the behavioral expression of naloxone-precipitated withdrawal. TCAP-1 (250 nmol/kg) treatment during morphine treatment was more effective than the optimal dosing of CP-154,526 (20 mg/kg) at suppressing the behavioral expression of naloxone-precipitated withdrawal, despite similar reduction of withdrawal-induced plasma CORT level increases.

CONCLUSIONS

These findings establish TCAP-1 as a potential therapeutic candidate for the prevention and treatment of morphine withdrawal.

Initiation of Buprenorphine Treatment of Opioid Use Disorder in Pediatric Emergency Departments

Pediatric emergency departments (EDs) in the United States are facing a rise in the number of children and adolescents who present with opioid use disorder (OUD), often driven by illicitly manufactured fentanyl. Medication treatment of pediatric OUD in the ED setting is often limited to symptomatic treatment of opioid withdrawal. Pediatric patients are rarely offered medications for OUD, especially in the ED setting. Buprenorphine is a partial opioid agonist that is Food and Drug Administration-approved for the treatment of OUD in patients aged 16 years and older. Adult studies have demonstrated that ED initiation of medication for OUD such as buprenorphine is feasible, safely treats withdrawal symptoms, and can improve patient compliance with outpatient follow-up. However, initiation of buprenorphine in the ED has not been well-studied in the pediatric population. We present 2 cases of adolescent patients, a 16-year-old male and 17-year-old female, who presented to the ED with opioid withdrawal. They were both diagnosed with severe OUD because of their use of counterfeit pills containing fentanyl. Both patients were successfully started on buprenorphine/naloxone in the pediatric ED before transitioning to an outpatient addiction clinic for continued treatment. The case series demonstrates the feasibility of ED-based buprenorphine initiation for adolescents, an important and timely intervention for adolescents with OUD.

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.

Oral ethanol prescribing for alcohol withdrawal syndrome: initial findings and future directions following implementation within a United Kingdom National Health Service setting

INTRODUCTION

Prescribing of ethanol may be an alternative to benzodiazepines for managing alcohol withdrawal syndrome. We present our experience of oral ethanol prescribing within an acute United Kingdom National Health Service setting.

METHODS

A retrospective review of patients presenting with alcohol withdrawal who were managed with oral ethanol or benzodiazepines was performed from data collected across two acute care settings. Ethanol prescribing inclusion: high risk of delirium tremens, or a history of harmful alcohol consumption (typically ≥30 units/day; in which 1 unit = 8 grams of alcohol; one standard United States drink = 14 grams of alcohol) or known to have a history of severe alcohol withdrawal, alcohol-related seizures or delirium tremens. Inverse propensity score weighting was used to partially account for variance between the two patient populations.

RESULTS

Fifty (82 per cent male; average age 50.9 years) and 93 (84 per cent male; average age 46.5 years) patients in receipt of benzodiazepines or ethanol, respectively, were included. The likelihood of hospital admission was significantly reduced when individuals were managed with ethanol (odds ratio 0.206 (95 per cent confidence interval; 0.066-0.641), Wald chi-square P = 0.006). In those not admitted, the treatment type had no significant impact on length of stay or the number of occasions a pharmacological agent was required. In those admitted, treatment had no significant effect on length of stay.

DISCUSSION

We offer preliminary evidence to support a role of oral ethanol in the management of patients with alcohol withdrawal. We have implemented a robust and translatable guideline. Despite limitations in the data set the impact of ethanol in reducing the likelihood of admission remained significant.

CONCLUSIONS

In individuals at significant risk of severe alcohol withdrawal, prescribing ethanol as part of a comprehensive care plan, may reduce unplanned admissions. The preliminary findings presented here warrant further assessment through prospective studies.

Mitragynine (Kratom)-Withdrawal behaviour and cognitive impairments can be ameliorated by an epigenetic mechanism

BACKGROUND AND PURPOSE

Kratom is a preparation from Mitragyna speciosa, which is used as a natural drug preparation for many purposes around the world. However, an overdose of Kratom may cause addiction-like problems including aversive withdrawal states resulting in cognitive impairments via unknown mechanisms. Its main psychoactive alkaloid is mitragynine, showing opioid-like properties.

EXPERIMENTAL APPROACH

Here, we analysed the neuropharmacological effects of mitragynine compared with morphine withdrawal in rats and searched for a pharmacological treatment option that may reverse the occurring cognitive deficits that usually aggravate withdrawal.

KEY RESULTS

We found that withdrawal from 14-day mitragynine (1-10 mg·kg-1·day-1) treatment caused dose-dependent behavioural withdrawal signs resembling those of morphine (5 mg·kg-1·day-1) withdrawal. However, mitragynine (5 and 10 mg·kg-1·day-1) withdrawal also induced impairments in a passive avoidance task. Mitragynine withdrawal not only reduced hippocampal field excitatory postsynaptic potential (fEPSP) amplitudes in basal synaptic transmission and long-term potentiation (LTP) but also reduced epigenetic markers, such as histone H3K9 and H4K12 expression. At the same time, it up-regulates HDAC2 expression. Targeting the epigenetic adaptations with the HDAC inhibitor, SAHA, reversed the effects of mitragynine withdrawal on epigenetic dysregulation, hippocampal input/output curves, paired-pulse facilitation, LTP and attenuated the cognitive deficit. However, SAHA amplified the effects of morphine withdrawal.

CONCLUSION AND IMPLICATIONS

The data from this work show that changes in histone expression and downstream hippocampal plasticity may explain mitragynine, but not morphine, withdrawal behaviours and cognitive impairments. Thus, it may provide a new treatment approach for aversive Kratom/mitragynine withdrawal and addiction.

Targeting GLP-1 receptors to reduce nicotine use disorder: Preclinical and clinical evidence

Nicotine use disorder (NUD) remains a leading cause of preventable death in the U.S. Unfortunately, current FDA-approved pharmacotherapies for smoking cessation have limited efficacy and are associated with high rates of relapse. One major barrier to long-term smoking abstinence is body weight gain during withdrawal. Nicotine withdrawal-induced body weight gain can also lead to development of chronic disease states like obesity and type II diabetes mellitus. Therefore, it is critical to identify novel pharmacotherapies for NUD that decrease relapse and nicotine withdrawal symptoms including body weight gain. Recent studies demonstrate that glucagon-like peptide-1 receptor (GLP-1R) agonists attenuate voluntary nicotine taking and seeking and prevent withdrawal-induced hyperphagia and body weight gain. Emerging evidence also suggests that GLP-1R agonists improve cognitive deficits, as well as depressive- and anxiety-like behaviors, which contribute to smoking relapse during withdrawal. While further studies are necessary to fully characterize the effects of GLP-1R agonists on NUD and understand the mechanisms by which GLP-1R agonists decrease nicotine withdrawal-mediated behaviors, the current literature supports GLP-1R-based approaches to treating NUD.

Barriers and facilitators to use of buprenorphine in state-licensed specialty substance use treatment programs: A survey of program leadership

INTRODUCTION

Medications for opioid use disorder (MOUD), including buprenorphine, reduce overdose risk and improve outcomes for individuals with opioid use disorder (OUD). However, historically, most non-opioid treatment program (non-OTP) specialty substance use treatment programs have not offered buprenorphine. Understanding barriers to offering buprenorphine in specialty substance use treatment settings is critical for expanding access to buprenorphine. This study aims to examine program-level attitudinal, financial, and regulatory factors that influence clients' access to buprenorphine in state-licensed non-OTP specialty substance use treatment programs.

METHODS

We surveyed leadership from state-licensed non-OTP specialty substance use treatment programs in New Jersey about organizational characteristics, including medications provided on- and off-site and percentage of OUD clients receiving any type of MOUD, and perceived attitudinal, financial, and regulatory barriers and facilitators to buprenorphine. The study estimated prevalence of barriers and compared high MOUD reach (n = 36, 35 %) and low MOUD reach (n = 66, 65 %) programs.

RESULTS

Most responding organizations offered at least one type of MOUD either on- or off-site (n = 80, 78 %). However, 71 % of organizations stated that fewer than a quarter of their clients with OUD use any type of MOUD. Endorsement of attitudinal, financial, and institutional barriers to buprenorphine were similar among high and low MOUD reach programs. The most frequently endorsed government actions suggested to increase use of buprenorphine were facilitating access to long-acting buprenorphine (n = 95, 96 %), education and stigma reduction for clients and families (n = 95, 95 %), and financial assistance to clients to pay for medications (n = 90, 90 %).

CONCLUSIONS

Although non-OTP specialty substance use programs often offer clients access to MOUD, including buprenorphine, most OUD clients do not actually receive MOUD. Buprenorphine uptake in these settings may require increased financial support for programs and clients, more robust education and training for providers, and efforts to reduce the stigma associated with medication among clients and their families.

Incidence of antidepressant discontinuation symptoms: a systematic review and meta-analysis

BACKGROUND

Antidepressant discontinuation symptoms are becoming an increasingly important part of clinical practice, but the incidence of antidepressant discontinuation symptoms has not been quantified. An estimate of antidepressant discontinuation symptoms incidence could inform patients and clinicians in the discontinuation of treatment, and provide useful information to researchers in antidepressant treatments. We aimed to assess the incidence of antidepressant discontinuation symptoms in patients discontinuing both antidepressants and placebo in the published literature.

METHODS

We systematically searched Medline, EMBASE, and CENTRAL from database inception until Oct 13, 2022 for randomised controlled trials (RCTs), other controlled trials, and observational studies assessing the incidence of antidepressant discontinuation symptoms. To be included, studies must have investigated cessation or tapering of an established antidepressant drug (excluding antipsychotics, lithium, or thyroxine) or placebo in participants with any mental, behavioural, or neurodevelopmental disorder. We excluded studies in neonates, and those using antidepressants for physical conditions such as pain syndromes due to organic disease. After study selection, summary data extraction, and risk of bias evaluation, data were pooled in random-effects meta-analyses. The main outcome was the incidence of antidepressant discontinuation symptoms after discontinuation of antidepressants or placebo. We also analysed the incidence of severe discontinuation symptoms. Sensitivity and meta-regression analyses tested a selection of methodological variables.

FINDINGS

From 6095 articles screened, 79 studies (44 RCTs and 35 observational studies) covering 21 002 patients were selected (72% female, 28% male, mean age 45 years [range 19·6-64·5]). Data on ethnicity were not consistently reported. 16 532 patients discontinued from an antidepressant, and 4470 patients discontinued from placebo. Incidence of at least one antidepressant discontinuation symptom was 0·31 (95% CI 0·27-0·35) in 62 study groups after discontinuation of antidepressants, and 0·17 (0·14-0·21) in 22 study groups after discontinuation of placebo. Between antidepressant and placebo groups of included RCTs, the summary difference in incidence was 0·08 [0·04-0·12]. The incidence of severe antidepressant discontinuation symptoms after discontinuation of an antidepressant was 0·028 (0·014-0·057) compared with 0·006 (0·002-0·013) after discontinuation of placebo. Desvenlafaxine, venlafaxine, imipramine, and escitalopram were associated with higher frequencies of discontinuation symptoms, and imipramine, paroxetine, and either desvenlafaxine or venlafaxine were associated with a higher severity of symptoms. Heterogeneity of results was substantial.

INTERPRETATION

Considering non-specific effects, as evidenced in placebo groups, the incidence of antidepressant discontinuation symptoms is approximately 15%, affecting one in six to seven patients who discontinue their medication. Subgroup analyses and heterogeneity figures point to factors not accounted for by diagnosis, medication, or trial-related characteristics, and might indicate subjective factors on the part of investigators, patients, or both. Residual or re-emerging psychopathology needs to be considered when interpreting the results, but our findings can inform clinicians and patients about the probable extent of antidepressant discontinuation symptoms without causing undue alarm.

FUNDING

None.

How Should Risks and Benefits of Short-Acting Opioids Be Evaluated in the Care of Inpatients With OUD?

Severe opioid withdrawal, risk of patient-initiated discharge, and some inpatients' use of unregulated substances prompt clinical and ethical questions considered in this commentary on a case. Short-acting opioids can be used to manage inpatients' pain and opioid use disorder (OUD) withdrawal symptoms. Including evidence-based interventions-such as naloxone kits, substance use equipment, and supervised consumption-in some inpatients' care plans may make those patients safer and reduce their risk of death. These and other strategies align with clinicians' ethical duties to minimize harms and maximize benefits for inpatients with OUD.

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.

Gradually tapering off antipsychotics: lessons for practice from case studies and neurobiological principles

PURPOSE OF REVIEW

There has been an increasing focus on deprescribing in psychiatry recently, particularly of antipsychotic medication, with recognition that not all patients with psychotic disorders require lifelong medication. We summarize some empirical and theoretical papers, and examine case studies to provide instruction on this topic.

RECENT FINDINGS

Recent studies have found that slower tapering (over months or longer) of antipsychotics is associated with a lower relapse rate than quicker tapering (weeks). Case studies presented suggest that the process of reduction is associated with the precipitation or exacerbation of psychotic symptoms and that a slower process of reduction may minimize this effect. This may be because faster reductions cause greater disruption of homeostatic equilibria, provoking psychotic symptoms either as direct withdrawal symptoms or consequences of nonpsychotic withdrawal symptoms (e.g. insomnia) - although not all patients will experience withdrawal symptoms. This suggests that smaller dose reductions, especially at lower doses, made very gradually, may minimize the risk of psychotic symptoms.

SUMMARY

Slower tapering of antipsychotics may provide time for adaptations made to the presence of the medications to resolve, thus reducing the disruption to homeostatic equilibrium caused by dose reduction, potentially reducing the risk of relapse. Exacerbation of psychotic symptoms on antipsychotic reduction may not represent evidence of the need for a higher dose of antipsychotic on a long-term basis but may indicate the need for more gradual reduction. Gradual reduction of antipsychotics, especially after long-term use in clinical practice is prudent.

Psychoactive plant derivatives (ayahuasca, ibogaine, kratom) and their application in opioid withdrawal and use disorder - a narrative review

The opioid epidemic and limited access to treatment for opioid withdrawal (OW) and opioid use disorder (OUD) has led individuals to seek alternative treatments. This narrative review aims to educate clinicians on the mechanisms of action, toxicity, and applications of psychoactive plant-based substances patients may be using to self-treat OUD and OW. We specifically discuss ayahuasca, ibogaine, and kratom as they have the most evidence for applications in OUD and OW from the last decade (2012-2022). Evidence suggests these substances may have efficacy in treating OW and OUD through several therapeutic mechanisms including their unique pharmacodynamic effects, rituals performed around ingestion, and increased neuroplasticity. The current evidence for their therapeutic application in OUD and OW is primarily based on small observational studies or animal studies. High-quality, longitudinal studies are needed to clarify safety and efficacy of these substances in treatment of OW and OUD.

Establishing a research agenda for the study and assessment of opioid withdrawal

The opioid crisis is an international public health concern. Treatments for opioid use disorder centre largely on the management of opioid withdrawal, an aversive collection of signs and symptoms that contribute to opioid use disorder. Whereas in the past 50 years more than 90 medications have been developed for depression, only five medications have been developed for opioid use disorder during this period. We posit that underinvestment has occurred in part due to an underdeveloped understanding of opioid withdrawal syndrome. This Personal View summarises substantial gaps in our understanding of opioid withdrawal that are likely to continue to limit major advancements in its treatment. There is no firm consensus in the field as to how withdrawal should be precisely defined; 10-550 symptoms of withdrawal can be measured on 18 scales. The imprecise understanding of withdrawal is likely to result in overestimating or underestimating the severity of an individual's withdrawal syndrome or potential therapeutic effects of different candidate medications. The severity of the opioid crisis is not remitting, and an international research agenda for the study and assessment of opioid withdrawal is necessary to support transformational changes in withdrawal management and treatment of opioid use disorder. Nine actionable targets are delineated here: develop a consensus definition of opioid withdrawal; understand withdrawal symptomatology after exposure to different opioids (particularly fentanyl); understand precipitated opioid withdrawal; understand how co-exposure of other drugs (eg, xylazine and stimulants) influences withdrawal expression; examine individual variation in withdrawal phenotypes; precisely characterise the protracted withdrawal syndrome; identify biomarkers of opioid withdrawal severity; identify predictors of opioid withdrawal severity; and understand which symptoms are most closely associated with treatment attrition or relapse. The US Food and Drug Administration recently established a formal indication for opioid withdrawal that has invigorated interest in drug development for opioid withdrawal management. Action is now needed to support these interests and help industry identify new classes of medications so that real change can be achieved for people with opioid use disorder.