Liraglutide Reduces Alcohol Consumption, Anxiety, Memory Impairment, and Synapse Loss in Alcohol Dependent Mice

Glucagon-like peptide 1 (GLP-1) analogues have been commercialized for the management of type 2 diabetes. Recent studies have underscored GLP-1's role as a modulator of alcohol-related behavior. However, the role of the GLP-1 analogue liraglutide on alcohol-withdrawal responses have not been fully elucidated. Liraglutide binds to the G-protein-coupled receptor and activates an adenylyl cyclase and the associated classic growth factor signaling pathway, which acts growth factor-like and neuroprotective properties. The underlying neurobiological mechanisms of liraglutide on alcohol withdrawal remains unknown. This study endeavored to explore the effects of liraglutide on the emotion and memory ability of alcohol-withdrawal mice, and synaptic morphology in the medial prefrontal cortex (mPFC) and the hippocampus (HP), and thus affects the relapse-like drinking of alcohol-withdrawal mice. The alcohol-withdrawal group was reintroduced to a 20% v/v alcohol and water through the two-bottle choice for four consecutive days, a period referred to as alcohol re-drinking. Male C57BL/6J mice were exposed to a regimen of 20% alcohol and water for a duration of 6 weeks. This regimen established the two-bottle choice model of alcohol exposure. Learning capabilities, memory proficiency, and anxiety-like behavior were evaluated using the Morris water maze, open field, and elevated plus maze paradigms. Furthermore, synaptic morphology and the levels of synaptic transport-related proteins were assessed via Golgi staining and Western Blot analysis after a two-week alcohol deprivation period. Alcohol re-drinking of alcohol-withdrawal mice was also evaluated using a two-bottle choice paradigm. Our findings indicate that liraglutide can substantially decrease alcohol consumption and preference (p < 0.05) in the alcohol group and enhance learning and memory performance (p < 0.01), as well as alleviate anxiety-like behavior (p < 0.01) of alcohol-withdrawal mice. Alcohol consumption led to a reduction in dendritic spine density in the mPFC and HP, which was restored to normal levels by liraglutide (p < 0.001). Furthermore, liraglutide was found to augment the levels of synaptic transport-related proteins in mice subjected to alcohol withdrawal (p < 0.01). The study findings corroborate that liraglutide has the potential to mitigate alcohol consumption and ameliorate the memory impairments and anxiety induced by alcohol withdrawal. The therapeutic efficacy of liraglutide might be attributed to its role in counteracting synapse loss in the mPFC and HP regions and thus prevented relapse-like drinking in alcohol-withdrawal mice.

Participant experiences in a pilot study for methamphetamine withdrawal treatment: Implications for retention

INTRODUCTION

There is little knowledge of the perspectives of people who use methamphetamine and have participated in clinical trials, and none for interventions not intended to address abstinence. A better understanding of these experiences could lead to more patient centred clinical trial design. This study seeks to understand the experiences of people who completed a clinical trial of lisdexamfetamine for the treatment of acute methamphetamine withdrawal.

METHODS

Thematic analysis of open-ended, semi-structured interviews with eight people who participated in an inpatient clinical trial of lisdexamfetamine for acute methamphetamine withdrawal. Interviews were conducted between days 3 and 6 of admission to an inner-city Sydney hospital.

RESULTS

Participants described how research procedures, the research setting, and the investigational product affected their experiences while enrolled in a clinical trial. Of particular importance to participants were transparent and low burden trial procedures, a welcoming trial environment, trusting relationships and effective communication, which were linked with the participants' subsequent decision to remain enrolled in the trial.

DISCUSSION

The experiences of participants in this clinical trial can be distilled into four meta-themes: agency, caring-trust, safety, and communication. Participants spontaneously linked these experiences with a capacity to remain enrolled in the study. By considering the experiences of trial participants in clinical trial design, researchers can improve the experiences of future trial participants and facilitate their choice to remain enrolled in clinical trials.

Ketamine in Critically Ill Patients: Use, Perceptions, and Potential Barriers

Objective: To evaluate practitioner use of ketamine and identify potential barriers to use in acutely and critically ill patients. To compare characteristics, beliefs, and practices of ketamine frequent users and non-users. Methods: An online survey developed by members of the Society of Critical Care Medicine (SCCM) Clinical Pharmacy and Pharmacology Section was distributed to physician, pharmacist, nurse practitioner, physician assistant and nurse members of SCCM. The online survey queried SCCM members on self-reported practices regarding ketamine use and potential barriers in acute and critically ill patients. Results: Respondents, 341 analyzed, were mostly adult physicians, practicing in the United States at academic medical centers. Clinicians were comfortable or very comfortable using ketamine to facilitate intubation (80.0%), for analgesia (77.9%), procedural sedation (79.4%), continuous ICU sedation (65.8%), dressing changes (62.4%), or for asthma exacerbation and status epilepticus (58.8% and 40.4%). Clinicians were least comfortable with ketamine use for alcohol withdrawal and opioid detoxification (24.7% and 23.2%). Most respondents reported "never" or "infrequently" using ketamine preferentially for continuous IV analgesia (55.6%) or sedation (61%). Responses were mixed across dosing ranges and duration. The most common barriers to ketamine use were adverse effects (42.6%), other practitioners not routinely using the medication (41.5%), lack of evidence (33.5%), lack of familiarity (33.1%), and hospital/institutional policy guiding the indication for use (32.3%). Conclusion: Although most critical care practitioners report feeling comfortable using ketamine, there are many inconsistencies in practice regarding dose, duration, and reasons to avoid or limit ketamine use. Further educational tools may be targeted at practitioners to improve appropriate ketamine use.

A Retrospective Evaluation of Adjunctive Phenobarbital vs. Benzodiazepine Alone for the Treatment of Moderate Alcohol Withdrawal in the Emergency Department

BACKGROUND

Phenobarbital has been used in the emergency department (ED) as both a primary and adjunctive medication for alcohol withdrawal, but previous studies evaluating its impact on patient outcomes are limited by heterogenous symptom severity.

OBJECTIVES

We compared the clinical outcomes of ED patients with moderate alcohol withdrawal who received phenobarbital, with or without benzodiazepines, with patients who received benzodiazepine treatment alone.

METHODS

This is a retrospective cohort study conducted at a single academic medical center utilizing chart review of ED patients with moderate alcohol withdrawal between 2015 and 2020. Patient encounters were classified into two treatment categories based on medication treatment: phenobarbital alone or in combination with benzodiazepines vs. benzodiazepines alone. Chi-square test or Fisher's exact was used to analyze categorical variables and the Student's t-test for continuous data.

RESULTS

Among the 287 encounters that met inclusion criteria, 100 received phenobarbital, compared with 187 that received benzodiazepines alone. Patients who received phenobarbital were provided significantly more lorazepam equivalents. There was a significant difference in the percentage of patient encounters that required admission to the hospital in the phenobarbital cohort compared with the benzodiazepine cohort (75% vs. 43.3%, p < 0.001). However, there was no difference in admission level of care to the floor (51.2% vs. 52.0%), stepdown (33.8% vs. 28%), or intensive care unit (15% vs. 20%), respectively.

CONCLUSIONS

Patients who received phenobarbital for moderate alcohol withdrawal were more likely to be admitted to the hospital, but there was no difference in admission level of care when compared with patients who received benzodiazepines alone. Patients who received phenobarbital were provided greater lorazepam equivalents in the ED.

Cannabidiol Reduced the Severity of Gastrointestinal Symptoms of Opioid Withdrawal in Male and Female Mice

Introduction: Opioid withdrawal is a powerful driver of drug-seeking behavior as relief from this aversive state through drug-taking is a strong negative reinforcer. There are currently limited treatment options available for opioid withdrawal and cannabidiol (CBD) has been identified as a potential novel therapeutic. This study explored the efficacy and dose dependency of CBD for reducing the severity of naloxone-precipitated and spontaneous oxycodone withdrawal (PW and SW, respectively) in male and female mice. Methods: Mice were administered saline or escalating doses of oxycodone, whereby 9, 17.8, 23.7, and 33 mg/kg oxycodone IP was administered twice daily on days 1-2, 3-4, 5-6, and 7-8, respectively. On the 9th day, a single 33 mg/kg dose of oxycodone (or saline) was administered. To precipitate withdrawal, on day 9, mice in the withdrawal conditions were administered an IP injection of 10 mg/kg naloxone 2 h after the final oxycodone injection and immediately before withdrawal testing. To elicit SW, a separate group of mice underwent withdrawal testing 24 h after their final oxycodone injection. Mice were treated with an IP injection of 0, 10, 30 or 100 mg/kg of CBD 60 min before testing. Withdrawal symptoms examined included gastrointestinal symptoms (fecal boli, diarrhea, and body weight loss), somatic symptoms (paw tremors), and negative affect (jumping). Results: A robust PW syndrome was observed in both male and female mice, whereas only male mice displayed an SW syndrome. CBD dose dependently reduced gastrointestinal symptoms during both PW and SW in male mice and during PW in female mice. CBD had no effect on PW- or SW-induced jumping in male mice. However, in female mice, the PW-induced increase in jumps was less pronounced in CBD-treated mice. The highest dose of CBD inhibited paw tremors during PW, but not SW, in male mice. Neither PW- nor SW-induced paw tremors were observed in female mice. Conclusions: The magnitude of effects on the gastrointestinal symptoms, their consistency across PW and SW, and both sexes, alongside the availability of CBD for clinical use, suggest further exploration of the potential for CBD to treat these symptoms could be justified.

Amelioration of morphine withdrawal syndrome by systemic and intranasal administration of mesenchymal stem cell-derived secretome in preclinical models of morphine dependence

BACKGROUND

Morphine is an opiate commonly used in the treatment of moderate to severe pain. However, prolonged administration can lead to physical dependence and strong withdrawal symptoms upon cessation of morphine use. These symptoms can include anxiety, irritability, increased heart rate, and muscle cramps, which strongly promote morphine use relapse. The morphine-induced increases in neuroinflammation, brain oxidative stress, and alteration of glutamate levels in the hippocampus and nucleus accumbens have been associated with morphine dependence and a higher severity of withdrawal symptoms. Due to its rich content in potent anti-inflammatory and antioxidant factors, secretome derived from human mesenchymal stem cells (hMSCs) is proposed as a preclinical therapeutic tool for the treatment of this complex neurological condition associated with neuroinflammation and brain oxidative stress.

METHODS

Two animal models of morphine dependence were used to evaluate the therapeutic efficacy of hMSC-derived secretome in reducing morphine withdrawal signs. In the first model, rats were implanted subcutaneously with mini-pumps which released morphine at a concentration of 10 mg/kg/day for seven days. Three days after pump implantation, animals were treated with a simultaneous intravenous and intranasal administration of hMSC-derived secretome or vehicle, and withdrawal signs were precipitated on day seven by i.p. naloxone administration. In this model, brain alterations associated with withdrawal were also analyzed before withdrawal precipitation. In the second animal model, rats voluntarily consuming morphine for three weeks were intravenously and intranasally treated with hMSC-derived secretome or vehicle, and withdrawal signs were induced by morphine deprivation.

RESULTS

In both animal models secretome administration induced a significant reduction of withdrawal signs, as shown by a reduction in a combined withdrawal score. Secretome administration also promoted a reduction in morphine-induced neuroinflammation in the hippocampus and nucleus accumbens, while no changes were observed in extracellular glutamate levels in the nucleus accumbens.

CONCLUSION

Data presented from two animal models of morphine dependence suggest that administration of secretome derived from hMSCs reduces the development of opioid withdrawal signs, which correlates with a reduction in neuroinflammation in the hippocampus and nucleus accumbens.

Xylazine suppresses fentanyl consumption during self-administration and induces a unique sex-specific withdrawal syndrome that is not altered by naloxone in rats

Prescription and illicit opioid use are a public health crisis, with the landscape shifting to fentanyl use. Since fentanyl is 100-fold more potent than morphine, its use is associated with a higher risk of fatal overdose that can be remediated through naloxone (Narcan) administration. However, recent reports indicate that xylazine, an anesthetic, is increasingly detected in accidental fentanyl overdose deaths. Anecdotal reports suggest that xylazine may prolong the fentanyl "high," alter the onset of fentanyl withdrawal, and increase resistance to naloxone-induced reversal of overdose. To date, no preclinical studies have evaluated the impacts of xylazine on fentanyl self-administration (SA; 2.5 μg/kg/infusion) or withdrawal to our knowledge. We established a rat model of xylazine/fentanyl co-SA and withdrawal and evaluated outcomes as a function of biological sex. When administered alone, chronic xylazine (2.5 mg/kg, intraperitoneal) induced unique sex-specific withdrawal symptomatology, whereby females showed delayed onset of signs and a possible enhancement of sensitivity to the motor-suppressing effects of xylazine. Xylazine reduced fentanyl consumption in both male and female rats regardless of whether it was experimenter-administered or added to the intravenous fentanyl product (0.05, 0.10, and 0.5 mg/kg/infusion) when compared to fentanyl SA alone. Interestingly, this effect was dose-dependent when self-administered intravenously. Naloxone (0.1 mg/kg, subcutaneous injection) did not increase somatic signs of fentanyl withdrawal, regardless of the inclusion of xylazine in the fentanyl infusion in either sex; however, somatic signs of withdrawal were higher across time points in females after xylazine/fentanyl co-SA regardless of naloxone exposure as compared to females following fentanyl SA alone. Together, these results indicate that xylazine/fentanyl co-SA dose-dependently suppressed fentanyl intake in both sexes and induced a unique withdrawal syndrome in females that was not altered by acute naloxone treatment. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Measuring Objective and Subjective Sleep during Lisdexamfetamine Treatment of Acute Methamphetamine Withdrawal: A Feasibility Study

INTRODUCTION

Sleep disturbance is common during methamphetamine (MA) use and withdrawal; however, the feasibility of combined subjective-objective measurement of sleep-wake has not been shown in this population. Actigraphy is a well-established, non-invasive measure of sleep-wake cycles with good concordance with polysomnography. This study aimed to investigate the feasibility and utility of using actigraphy and sleep diaries to investigate sleep during MA withdrawal.

METHODS

We conducted a feasibility and utility study of actigraphy and sleep diaries during a clinical trial of lisdexamfetamine for MA withdrawal. Participants were inpatients for 7 days, wore an actigraph (Philips Actiwatch 2) and completed a modified Consensus Sleep Diary each morning. Participants were interviewed between days 3-5.

RESULTS

Ten participants (mean age 37 years, 90% male) were enrolled. No participant removed the device prematurely. Participants interviewed (n = 8) reported that the actigraph was not difficult or distracting to wear or completion of daily sleep diary onerous. Actigraphic average daily sleep duration over 7 days was 568 min, sleep onset latency 22.4 min, wake after sleep onset (WASO) 75.2 min, and sleep efficiency 83.6%. Sleep diaries underreported daily sleep compared with actigraphy (sleep duration was 56 min (p = 0.008) and WASO 47 min (p < 0.001) less). Overall sleep quality was 4.4 on a nine-point Likert scale within the diary.

CONCLUSIONS

Continuous actigraphy is feasible to measure sleep-wake in people withdrawing from MA, with low participant burden. We found important differences in self-reported and actigraphic sleep, which need to be explored in more detail.

Substitution therapy for patients with alcohol dependence: Mechanisms of action and efficacy

New approaches for the treatment of alcohol dependence (AD) may improve patient outcomes. Substitution maintenance therapy is one of the most effective treatment options for opioid and nicotine use disorders. So far, there has been little attention to substitution therapy for the treatment of AD. Here, we explain the mechanistic foundations of alcohol substitution maintenance therapy. Alcohol has many primary targets in the brain (and other organs) and the physical interaction of ethanol molecules with these specific ethanol-sensitive sites on a variety of ionotropic receptors (e.g. GABA-A, NMDA, and nicotinic acetylcholine (nACh) receptors) and ion channels provides the rationale for substitution. As such, a variety of compounds can interact with those ethanol-sensitive sites and can thus substitute for some of the effects of alcohol. For some of these compounds, alcohol discrimination studies have shown their substitution potential. Accordingly, potential substitution treatments include agonists acting at GABA receptors such as sodium oxybate, baclofen and benzodiazepines, NMDA receptor antagonists such as ketamine and memantine, or nAChRs agonists such as varenicline. All these compounds are already approved for other indications and we present clinical evidence for these drugs in the treatment of alcohol withdrawal syndrome (AWS) and in the long-term treatment of AD, and outline future steps for their acceptance as substitution treatment in AD. Finally, we discuss the substitution approach of managed alcohol programs for the most severely affected homeless populations. Results showed that sodium oxybate is probably the closest to a substitution therapy for AD and is already approved for the treatment of AWS and in the long-term treatment of AD in some countries. In conclusion, we argue that better AD treatment can be provided if substitution maintenance treatments for alcohol are implemented at a similar scale as for opioid and nicotine use disorder.

Cannabidiol as a potential cessation therapeutic: Effects on intravenous nicotine self-administration and withdrawal symptoms in mice

Cigarette smoking remains a leading cause of preventable disease and death worldwide. Due to the devastating negative health effects of smoking, many users attempt to quit, but few are successful in the long-term. Thus, there is a critical need for novel therapeutic approaches. In these investigations, we sought to examine whether cannabidiol (CBD) has the potential to be repurposed as a nicotine cessation therapeutic. In the first study, male and female mice were trained to respond for intravenous nicotine infusions at either a low or moderate nicotine dose and then were pretreated with CBD prior to their drug-taking session. We found that CBD produced a significant decrease in the number of nicotine rewards earned, and this effect was evidenced across CBD doses and with both the low and moderate levels of nicotine intake. These effects on drug intake were not due to general motor-related effects, since mice self-administering food pellets did not alter their behavior with CBD administration. The potential effects of CBD in mitigating nicotine withdrawal symptoms were then investigated. We found that CBD attenuated the somatic signs of nicotine withdrawal and prevented nicotine's hyperalgesia-inducing effects. Taken together, these results demonstrate that modulation of cannabinoid signaling may be a viable therapeutic option as a smoking cessation aid.

Repurposing drugs for treatment of alcohol use disorder

Repurposing drugs for the treatment of alcohol dependence involves the use of drugs that were initially developed for other conditions, but have shown promise in reducing alcohol use or preventing relapse. This approach can offer a more cost-effective and time-efficient alternative to developing new drugs from scratch. Currently approved medications for alcohol use disorder (AUD) include acamprosate, disulfiram, naltrexone, nalmefene, baclofen, and sodium oxybate. Acamprosate was developed specifically for AUD, while disulfiram's alcohol-deterrent effects were discovered incidentally. Naltrexone and nalmefene were originally approved for opioids but found secondary applications in AUD. Baclofen and sodium oxybate were repurposed from neurological conditions. Other drugs show promise. Topiramate and zonisamide, anticonvulsants, demonstrate efficacy in reducing alcohol consumption. Another anticonvulsant, gabapentin has been disappointing overall, except in cases involving alcohol withdrawal symptoms. Varenicline, a nicotinic receptor agonist, benefits individuals with less severe AUD or concurrent nicotine use. Ondansetron, a 5-HT3 antagonist, has potential for early-onset AUD, especially when combined with naltrexone. Antipsychotic drugs like aripiprazole and quetiapine have limited efficacy. Further investigation is needed for potential repurposing of α1 adrenergic receptor antagonists prazosin and doxazosin, glucocorticoid receptor antagonist mifepristone, the phosphodiesterase inhibitor Ibudilast, the cysteine prodrug N-acetylcysteine, and the OX1R and OX2R blocker Suvorexant. This review supports repurposing drugs as an effective strategy for expanding treatment options for AUD.

LY2444296, a κ-opioid receptor antagonist, selectively reduces alcohol drinking in male and female Wistar rats with a history of alcohol dependence

Alcohol use disorder (AUD) remains a major public health concern. The dynorphin (DYN)/κ-opioid receptor (KOP) system is involved in actions of alcohol, particularly its withdrawal-associated negative affective states. This study tested the ability of LY2444296, a selective, short-acting, KOP antagonist, to decrease alcohol self-administration in dependent male and female Wistar rats at 8 h abstinence. Animals were trained to orally self-administer 10% alcohol (30 min/day for 21 sessions) and were made dependent via chronic intermittent alcohol vapor exposure for 6 weeks or exposed to air (nondependent). After 6 weeks, the effect of LY2444296 (0, 3, and 10 mg/kg, p.o.) was tested on alcohol self-administration at 8 h of abstinence. A separate cohort of rats was prepared in parallel, and their somatic withdrawal signs and alcohol self-administration were measured after LY2444296 administration at 8 h, 2 weeks, and 4 weeks abstinence. LY2444296 at 3 and 10 mg/kg significantly reduced physical signs of withdrawal in dependent rats at 8 h abstinence, only. Furthermore, 3 and 10 mg/kg selectively decreased alcohol self-administration in dependent rats at only 8 h abstinence. These results highlight the DYN/KOP system in actions of alcohol during acute abstinence, suggesting KOP antagonism could be beneficial for mitigating acute withdrawal signs and, in turn, significantly reduce excessive alcohol consumption associated with AUD.

Attenuation of cannabis withdrawal symptoms by Prosopis farcta extract, its luteolin and melatonin in mice: Involvement of brain-derived neurotrophic factor and dopamine

The aim of this study was the identification of luteolin in Prosopis farcta extract (PFE) and melatonin to evaluate its effect on THC withdrawal syndrome in mice. Luteolin was identified by high-performance liquid chromatography (HPCL). Signs of toxicity of mice in PFE and luteolin were monitored for LD50 calculation. The behavioral symptoms of THC withdrawal (stereotypies, ambulation, and inactivity time) induced by the rimonabant challenge were illustrated in THC-dependent mice receiving PFE, luteolin, and melatonin. The expression of mature BDNF (mBDNF) was evaluated by Western blot analysis. The dopamine concentrations were measured using HPLC. PFE and luteolin LD50 were 650 and 220 mg/kg, respectively. PFE (300 mg/kg), all doses of luteolin, and melatonin increased significantly the mBDNF expression and decreased the dopamine concentration. The findings suggest that PFE, luteolin, and melatonin are mighty in reducing the signs of THC withdrawal. It seems these effects were due to a decrease in dopamine concentration level and an increase in mBDNF protein expression in mice brains.

Responses to a "Typical" Morning Dose of Kratom in People Who Use Kratom Regularly: A Direct-Observation Study

INTRODUCTION

Use of kratom has outpaced systematic study of its effects, with most studies reliant on retrospective self-report.

METHODS

We aimed to assess acute effects following kratom use in adults who use regularly, and quantify alkaloids in the products, urine, and plasma. Between July and November 2022, 10 adults came to our clinic and orally self-administered their typical kratom dose; blinding procedures were not used. Physiological measures included blood pressure, respiratory rate, heart rate, pulse oximetry, temperature, and pupil diameter. Subjective outcomes included Subjective Opioid Withdrawal Scale, Addiction Research Center Inventory, and Drug Effects Questionnaire. Psychomotor performance was also assessed.

RESULTS

Participants were 6 men and 4 women, mean age 41.2 years. Nine were non-Hispanic White; 1 was biracial. They had used kratom for 6.6 years (SD, 3.8 years) on average (2.0-14.1). Sessions were 190.89 minutes on average (SD, 15.10 minutes). Mean session dose was 5.16 g (median, 4.38 g; range, 1.1-10.9 g) leaf powder. Relative to baseline, physiological changes were minor. However, pupil diameter decreased (right, b = -0.70, P < 0.01; left, b = -0.73, P < 0.01) 40-80 minutes postdose and remained below baseline >160 minutes. Subjective Opioid Withdrawal Scale pre-dosing was mild (5.5 ± 3.3) and decreased postdose (b = [-4.0, -2.9], P < 0.01). Drug Effects Questionnaire "feeling effects" increased to 40/100 (SD, 30.5) within 40 minutes and remained above baseline 80 to 120 minutes (b = 19.0, P = 0.04), peaking at 72.7/100; 6 participants rated euphoria as mild on the Addiction Research Center Inventory Morphine-Benzedrine-scale. Psychomotor performance did not reliably improve or deteriorate postdosing.

CONCLUSIONS

Among regular consumers, we found few clinically significant differences pre- and post-kratom dosing. Alkaloidal contents in products were within expected ranges.

The neutral CB1 antagonist AM6527 reduces ethanol seeking, binge-like consumption, reinforcing, and withdrawal effects in male and female mice

RATIONALE

Alcohol use disorder (AUD) is a debilitating physiological and psychiatric disorder which affects individuals globally. The current pharmacological interventions to treat AUD are limited, and hence there is an urgent need for a novel pharmacological therapy which can be effective and safe across the population.

OBJECTIVE

We aimed to investigate a novel neutral cannabinoid receptor-1 (CB1R) antagonist, AM6527, in several preclinical models of ethanol consumption using male and female C57BL6/J mice.

METHODS

Independent groups of male and female mice were subjected to repeated cycles of drinking in the dark (DID), or intermittent access to alcohol (IAA) procedures. Twenty minutes prior to ethanol access in each procedure, animals were treated with intraperitoneal injections of either 1, 3, and 10 mg/kg of AM6527 or its respective vehicle. Acamprosate (100, 200, 300, and 400 mg/kg) or its respective vehicle was used as a positive control. Separate groups of male mice were subjected to a chain schedule of ethanol reinforcement to gain access to ethanol wherein completion of a fixed interval (FI; 5 min) schedule (link 1: "Seeking") was reinforced with continuous access to ethanol (fixed ratio; FR1) for up to 1.8 g/kg (link 2: "consumption"). All the animals were treated with 1, 3, and 10 mg/kg of AM6527 or its respective vehicle 20 mins prior to the start of the FI chain of the procedure. Separately, AM6527 was also evaluated in male and female mice undergoing acute ethanol withdrawal following 8 weeks of intermittent or continuous access to 20% ethanol drinking.

RESULTS

In both DID and IAA procedures, AM6527 reduced ethanol consumption in a dose-related manner in both male and female mice. AM6527 produced no tolerance in the DID procedure; mice treated with 3 mg/kg of AM6527 for 3 weeks continuously drank significantly smaller amounts of ethanol as compared to vehicle-treated mice over a period of three DID cycles. Moreover, in the IAA procedure, AM6527 caused an increase in water intake over the 24-h period. Acamprosate transiently reduced ethanol intake in male mice in both the DID and the IAA procedures but failed to produce any significant effect in female mice. AM6527 also produced a decrease in the FI responding ("ethanol seeking") in animals trained to self-administer ethanol. Lastly, AM6527 mitigated neurological withdrawal signs, i.e., handling induced convulsions (HIC) in mice undergoing acute ethanol withdrawal.

CONCLUSIONS

Current findings support previous studies with CB1R neutral antagonist in reducing voluntary ethanol intake and seeking behavior. Based on results shown in this work, AM6527 can be developed as a first in class CB1R neutral antagonist to treat AUD in both males and females.

Mifepristone decreases nicotine intake in dependent and non-dependent adult rats

BACKGROUND

Addiction to tobacco and nicotine products has adverse health effects and afflicts more than a billion people worldwide. Therefore, there is an urgent need for new treatments to reduce tobacco and nicotine use. Glucocorticoid receptor blockade shows promise as a novel treatment for drug abuse and stress-related disorders.

AIM

These studies aim to investigate whether glucocorticoid receptor blockade with mifepristone diminishes the reinforcing properties of nicotine in rats with intermittent or daily long access to nicotine.

METHODS

The rats self-administered 0.06 mg/kg/inf of nicotine for 6 h per day, with either intermittent or daily access for 4 weeks before treatment with mifepristone. Daily nicotine self-administration models regular smoking, while intermittent nicotine self-administration models occasional smoking. To determine whether the rats were dependent, they were treated with the nicotinic acetylcholine receptor antagonist mecamylamine, and somatic signs were recorded.

RESULTS

The rats with intermittent access to nicotine had a higher level of nicotine intake per session than those with daily access but only the rats with daily access to nicotine showed signs of physical dependence. Furthermore, mecamylamine increased nicotine intake during the first hour of access in rats with daily access but not in those with intermittent access. Mifepristone decreased total nicotine intake in rats with intermittent and daily access to nicotine. Moreover, mifepristone decreased the distance traveled and rearing in the open field test and operant responding for food pellets.

CONCLUSION

These findings indicate that mifepristone decreases nicotine intake but this effect may be partially attributed to the sedative effects of mifepristone.

Eliminating the benzos: A benzodiazepine-sparing approach to preventing and treating alcohol withdrawal syndrome

BACKGROUND

Alcohol withdrawal syndrome (AWS) represents significant cost to the hospitalized trauma population from a clinical and financial perspective. Historically, AWS has been managed with benzodiazepines. Despite their efficacy, benzodiazepines carry a heavy adverse effect profile. Recently, benzodiazepine-sparing protocols for the prophylaxis and treatment of AWS have been used in medical patient populations. Most existing benzodiazepine-sparing protocols use phenobarbital, while ours primarily uses gabapentin and clonidine, and no such protocol has been developed and examined for safety and efficacy specifically within a trauma population.

METHODS

In December of 2019, we implemented our benzodiazepine-sparing protocol for trauma patients identified at risk for alcohol withdrawal on admission. Trauma patients at risk for AWS admitted to an academic Level 1 trauma center before (conventional) and after (benzodiazepine-sparing [BS]) protocol implementation were compared. Outcomes examined include morphine milligram equivalent dosing rates and lorazepam equivalent dosing rates as well as the Clinical Institute Withdrawal Assessment for Alcohol, revised (CIWA-Ar) scores, hospital length of stay, intensive care unit length of stay, and ventilator days.

RESULTS

A total of 387 conventional and 134 benzodiazepine sparing patients were compared. Injury Severity Score (13 vs. 16, p = 0.10) and admission alcohol levels (99 vs. 149, p = 0.06) were similar. Patients in the BS pathway had a lower maximum daily CIWA-Ar (2.7 vs. 1.5, p = 0.04). While mean morphine milligram equivalent per day was not different between groups (31.5 vs. 33.6, p = 0.49), mean lorazepam equivalents per day was significantly lower in the BS group (1.1 vs. 0.2, p < 0.01). Length of stay and vent days were not different between the groups.

CONCLUSION

Implementation of a benzodiazepine-sparing pathway that uses primarily clonidine and gabapentin to prevent and treat alcohol withdrawal syndrome in trauma patients is safe, reduces the daily maximum CIWA-Ar, and significantly decreases the need for benzodiazepines. Future studies will focus on outcomes affected by avoiding AWS and benzodiazepines in the trauma population.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

Comparison of phenobarbital monotherapy to a benzodiazepine-based regimen for management of alcohol withdrawal syndrome in trauma patients

BACKGROUND

Alcohol withdrawal syndrome (AWS) is associated with increased morbidity and mortality in the trauma population. Benzodiazepines (BZDs) are standard of care for AWS; however, given the risk of delirium with BZDs and reports of BZD-refractory withdrawal, phenobarbital (PHB) has emerged as an alternative therapy for AWS. Safety and efficacy studies of PHB for AWS in trauma patients are lacking. Our aim was to compare a BZD versus PHB protocol in the management of AWS in trauma patients.

METHODS

We performed a retrospective cohort study at a level 1 trauma center of patients at risk for AWS managed with either a BZD or a low-dose oral PHB regimen. Patients were excluded if they were taking BZDs or barbiturates before admission, received propofol or dexmedetomidine before initiation of the study drug, presented with delirium tremens or seizures, or died or discharged within 24 hours of presentation. The primary outcome was complicated AWS (seizures or alcohol withdrawal delirium/delirium tremens). Secondary outcomes included uncomplicated AWS; therapy escalation; oversedation; delirium-, intensive care unit-, and ventilator-free days; and length of stay.

RESULTS

A total of 411 patients were identified; 118 received BZD, and 293 received PHB. The odds of developing complicated AWS with PHB versus BZD-based therapy were not statistically significant (odds ratio [OR], 0.52; 95% confidence interval [CI], 0.21-1.39); however, patients receiving PHB were less likely to develop uncomplicated AWS (OR, 0.08; 95% CI, 0.04-0.14) and less likely to require escalation of therapy (OR, 0.45; 95% CI, 0.24-0.84). The PHB group had a length of stay 3.1 days shorter than the BZD group ( p = 0.002). There was no difference in intensive care unit-, ventilator-, or delirium-free days.

CONCLUSION

A PHB-based protocol for the management of AWS is a safe and effective alternative to BZD-based regimens in trauma patients.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

Impacts of xylazine on fentanyl demand, body weight, and acute withdrawal in rats: A comparison to lofexidine

The opioid use landscape has recently shifted to include xylazine, a veterinary anesthetic, as an adulterant in the fentanyl supply. The health impacts of xylazine as an emerging fentanyl adulterant has raised alarm regarding xylazine as a public health threat, warranting research on the impacts of xylazine on fentanyl's behavioral effects. No prior studies have evaluated the effects of xylazine on fentanyl consumption at various unit doses, fentanyl demand, or withdrawal as compared to the Food and Drug Administration-approved opioid withdrawal medication, lofexidine (Lucemyra®). This is important because lofexidine and xylazine are both adrenergic α2a (A2aR) agonists, however, lofexidine is not a noted fentanyl adulterant. Here we evaluated xylazine and lofexidine combined with self-administered fentanyl doses in male and female rats and evaluated fentanyl demand, body weight, and acute withdrawal. Consumption of fentanyl alone increased at various unit doses compared to saline. Xylazine but not lofexidine shifted fentanyl consumption downward at a number of unit doses, however, both lofexidine and xylazine suppressed fentanyl demand intensity as compared to a fentanyl alone control group. Further, both fentanyl + lofexidine and fentanyl + xylazine reduced behavioral signs of fentanyl withdrawal immediately following SA, but signs increased by 12 h only in the xylazine co-exposed group. Weight loss occurred throughout fentanyl SA and withdrawal regardless of group, although the xylazine group lost significantly more weight during the first 24 h of withdrawal than the other two groups. Severity of weight loss during the first 24 h of withdrawal was also correlated with severity of somatic signs of fentanyl withdrawal. Together, these results suggest that body weight loss may be an important indicator of withdrawal severity during acute withdrawal from the xylazine/fentanyl combination, warranting further translational evaluation.

Effects of inhaled low-concentration xenon gas on naltrexone-precipitated withdrawal symptoms in morphine-dependent mice

BACKGROUND

Opioid withdrawal symptoms (OWS) are highly aversive and prompt unprescribed opioid use, which increases morbidity, mortality, and, among individuals being treated for opioid use disorder (OUD), recurrence. OWS are driven by sympathetic nervous system (SNS) hyperactivity that occurs when blood opioid levels wane. We tested whether brief inhalation of xenon gas, which inhibits SNS activity and is used clinically for anesthesia and diagnostic imaging, attenuates naltrexone-precipitated withdrawal-like signs in morphine-dependent mice.

METHODS

Adult CD-1 mice were implanted with morphine sulfate-loaded (60 mg/ml) minipumps and maintained for 6 days to establish morphine dependence. On day 7, mice were given subcutaneous naltrexone (0.3 mg/kg) and placed in a sealed exposure chamber containing either 21% oxygen/balance nitrogen (controls) or 21% oxygen/added xenon peaking at 30%/balance nitrogen. After 10 minutes, mice were transferred to observation chambers and videorecorded for 45 minutes. Videos were scored in a blind manner for morphine withdrawal behaviors. Data were analyzed using 2-way ANOVAs testing for treatment and sex effects.

RESULTS AND CONCLUSIONS

Xenon-exposed mice exhibited fewer jumps (P = 0.010) and jumping suppression was detectible within the first 10-minute video segment, but no sex differences were detected. Brief inhalation of low concentration xenon rapidly and substantially attenuated naltrexone-precipitated jumping in morphine-dependent mice, suggesting that it can inhibit OWS. If xenon effects translate to humans with OUD, xenon inhalation may be effective for reducing OWS, unprescribed opioid use, and for easing OUD treatment initiation, which could help lower excess morbidity and mortality associated with OUD.

Pupillary response to percutaneous auricular vagus nerve stimulation in alcohol withdrawal syndrome: A pilot trial

BACKGROUND

Autonomic symptoms in alcohol withdrawal syndrome (AWS) are associated with a sympathetic-driven imbalance of the autonomic nervous system. To restore autonomic balance in AWS, novel neuromodulatory approaches could be beneficial. We conducted a pilot trial with percutaneous auricular vagus nerve stimulation (pVNS) in AWS and hypothesized that pVNS will enhance the parasympathetic tone represented by a reduction of pupillary dilation in a parasympatholytic pharmacological challenge.

METHODS

Thirty patients suffering from alcohol use disorder, undergoing AWS, and stable on medication, were recruited in this open-label, single-arm pilot trial with repeated-measure design. Peripheral VNS (monophasic volt impulses of 1 msec, alternating polarity, frequency 1 Hz, amplitude 4 mV) was administered at the left cymba conchae for 72 h, followed by pupillometry under a tropicamide challenge. We assessed craving with a visual analog scale. We used pupillary mean as the dependent variable in a repeated-measures ANOVA (rmANOVA).

RESULTS

A repeated-measures ANOVA resulted in a significant difference for pupillary diameter across time and condition (F(2,116) = 27.97, p < .001, ηp2 > .14). Tukey-adjusted post hoc analysis revealed a significant reduction of pupillary diameter after pVNS. Alcohol craving was significantly reduced after pVNS (p < .05, Cohen's d = 1.27).

CONCLUSION

Our study suggests that pVNS activates the parasympathetic nervous system in patients with acute AWS, and that this activation is measurable by pupillometry. To this end, pVNS could be beneficial as a supportive therapy for AWS. Potential confounding effects of anti-craving treatment should be kept in mind.

Examining Adult Patients' Success with Discontinuing Long-term Benzodiazepine Use: a Qualitative Study

BACKGROUND

Little is known about patients' experiences with benzodiazepine (BZD) discontinuation, which is thought to be challenging given the physiological and psychological dependence and accompanying potential for significant withdrawal symptoms. The marked decline in BZD prescribing over the past decade in the US Department of Veterans Affairs healthcare system presents an important opportunity to examine the experience of BZD discontinuation among long-term users.

OBJECTIVE

Examine the experience of BZD discontinuation among individuals prescribed long-term BZD treatment to identify factors that contributed to successful discontinuation.

DESIGN

Descriptive qualitative analysis of semi-structured interviews conducted between April and December of 2020.

PARTICIPANTS

A total of 21 Veterans who had been prescribed long-term BZD pharmacotherapy (i.e., > 120 days of exposure in a 12-month period) and had their BZD discontinued.

APPROACH

We conducted semi-structured interviews with Veteran participants to learn about their BZD use and the process of discontinuation, with interviews recorded and transcribed verbatim. Data were deductively and inductively coded and coded text entered into a matrix to identify factors that contributed to successful BZD discontinuation.

KEY RESULTS

The mean age of interview participants was 63.0 years (standard deviation 3.9); 94.2% were male and 76.2% were white. Of 21 participants, only 1 had resumed BZD treatment (prescribed by a non-VA clinician). Three main factors influenced success with discontinuation: (1) participants' attitudes toward BZDs (e.g., risks of long-term use, perceived lack of efficacy, potential for dependence); (2) limited withdrawal symptoms; and (3) effective alternatives, either from their clinician (e.g., medication, psychotherapy) or identified by participants.

CONCLUSIONS

BZD discontinuation after long-term use is relatively well tolerated, and participants appreciated reducing their medication exposure, particularly to one associated with physical dependence. These findings may help reduce both patient and clinician anxiety related to BZD discontinuation.

Competitive inhibition of nicotine acetylcholine receptors using microneedles of nicotine and varenicline for smoking withdrawal therapy

Current strategies for smoking withdrawal conditions involve monotherapy of nicotine and combinational therapy of nicotine with varenicline or bupropion as per the CDC and FDA. The available dosage forms for nicotine are patches, gums, inhalers and nasal sprays, bupropion and varenicline are available in tablet form. This research work focused on developing a microneedle delivery system to deliver combination drug for overcoming the obstacles encountered by oral route of administration of varenicline such as severe side effects (mood swings, agitation, depressed behaviour, seizures, etc), and nicotine therapy challenges such as short half-life, repeated dosing, nausea, and vomiting. The nanoparticles of nicotine prepared by nanoprecipitation method showed particle size PTZ (356.6 ± 65.98), percentage entrapment efficiency (35.55 % ± 0.007), in-vitro drug release (47.89 % ± 0.7) for 72 h. Microneedles showed height (600 μm), width (350 μm), and tip diameter (10 μm). The nanoparticles encapsulated in microneedles showed in-vitro sustained delivery of nicotine (67.00 % ± 4.92) and varenicline (79.78 % ± 1.09) in 48 h. Nicotine released in a sustained manner attaches to the nicotine acetylcholine receptors (nAchR) to release dopamine for controlling the withdrawal challenges such as anxiety, irritability, cravings, disturbed sleep pattern, etc. The varenicline released from microneedles binds to the nAchR and inhibits dopamine release responsible for the euphoric effect induced by nicotine, and thus assists in curbing the nicotine withdrawal symptoms. This combination microneedle system offers prolonged treatment in a single application for smoking withdrawal conditions wherein patients are not in stage of oral dosing because of repeated dosing resulting in adverse effects like seizures, hypertension, sleep disturbances, insomnia, and nausea.