Pharmacological treatments for opiate and alcohol addiction: A historical perspective of the last 50 years

Provision of medications to treat opioid use disorder via a mobile health unit: A scoping review

INTRODUCTION

Mobile health units (MHUs) provide a variety of low-barrier services to populations that face systemic barriers to healthcare access. However, MHUs are not a common delivery method for medications to treat opioid use disorder (MOUD), and, of these, there is no consensus regarding MHU targeted objectives and outcomes. This scoping review seeks to summarize the state of the literature examining the delivery of MOUD by MHUs in the United States.

METHODS

A search of PubMed, PsycInfo, and CINAHL on February 21, 2023, found 223 articles. Two authors completed title and abstract and full text reviews and extracted data relevant to intervention and study design, program objectives, and study outcomes. Ten articles fit the study's inclusion criteria (nine total interventions).

RESULTS

Of the 10 studies, six were cohort designs, three were cross-sectional (one with qualitative interviews), and one study conducted qualitative interviews only. Most studies were located in the Northeastern United States. MHU interventions primarily aimed to provide MOUD and to retain populations in treatment. Two interventions aimed to engage patients and then transfer them to fixed-site MOUD providers. Across four interventions that provided buprenorphine, 1- and 3-month retention rates varied from 31.6 % to 72.3 % and 26.2 % to 58.5 %, respectively. Qualitative interviews found that MOUD delivery from the MHU was characterized by less stigma/judgment and greater privacy compared to fixed-site, and it was flexible and low-barrier. MHUs were reportedly underutilized by the target populations, suggesting a lack of awareness from community members with opioid use disorder.

CONCLUSIONS

MHUs that deliver MOUD are both under-provided and -utilized. Future research should continue to assess MOUD provision from MHUs with an emphasis on robust study design, application to other formulations of MOUD, and evaluation of outcomes such as participant satisfaction and key informant perceived challenges.

REGISTRATION

Submitted to Open Science Framework (OSF) Repository on February 6, 2023.

Promising immunomodulators for management of substance and alcohol use disorders

INTRODUCTION

The neuroimmune system has emerged as a novel target for the treatment of substance use disorders (SUDs), with immunomodulation producing encouraging therapeutic benefits in both preclinical and clinical settings.

AREAS COVERED

In this review, we describe the mechanism of action and immune response to methamphetamine, opioids, cocaine, and alcohol. We then discuss off-label use of immunomodulators as adjunctive therapeutics in the treatment of neuropsychiatric disorders, demonstrating their potential efficacy in affective and behavioral disorders. We then discuss in detail the mechanism of action and recent findings regarding the use of ibudilast, minocycline, probenecid, dexmedetomidine, pioglitazone, and cannabidiol to treat (SUDs). These immunomodulators are currently being investigated in clinical trials described herein, specifically for their potential to decrease substance use, withdrawal severity, central and peripheral inflammation, comorbid neuropsychiatric disorder symptomology, as well as their ability to improve cognitive outcomes.

EXPERT OPINION

We argue that although mixed, findings from recent preclinical and clinical studies underscore the potential benefit of immunomodulation in the treatment of the behavioral, cognitive, and inflammatory processes that underlie compulsive substance use.

The Role of Estrogen Signaling and Exercise in Drug Abuse: A Review

BACKGROUND

Discovering how sex differences impact the efficacy of exercise regimens used for treating drug addiction is becoming increasingly important. Estrogen is a hormone believed to explain a large portion of sex differences observed during drug addiction, and why certain exercise regimens are not equally effective between sexes in treatment. Addiction is currently a global hindrance to millions, many of whom are suffering under the influence of their brain's intrinsic reward system coupled with external environmental factors. Substance abuse disorders in the U.S. alone cost billions of dollars annually.

REVIEW SUMMARY

Studies involving the manipulation of estrogen levels in female rodents, primarily via ovariectomy, highlight its impact regarding drug addiction. More specifically, female rodents with higher estrogen levels during the estrus phase increase cocaine consumption, whereas those in the non-estrus phase (low estrogen levels) decrease cocaine consumption. If estrogen is reintroduced, self-administration increases once again. Exercise has been proven to decrease relapse tendency, but its effect on estrogen levels is not fully understood.

CONCLUSIONS

Such findings and results discussed in this review suggest that estrogen influences the susceptibility of females to relapse. Therefore, to improve drug-abuse-related treatment, exercise regimens for females should be generated based on key sex differences with respect to males.

Exploring the Role of DARPP-32 in Addiction: A Review of the Current Limitations of Addiction Treatment Pathways and the Role of DARPP-32 to Improve Them

We are amidst a global addiction crisis, yet stigmas surrounding addiction counterintuitively prevail. Understanding and appreciating the neurobiology of addiction is essential to dissolve this stigma and for the development of new pharmacological agents to improve upon currently narrow therapeutic options. This review highlights this and evaluates dopamine-and-cAMP-regulated phosphoprotein, Mr 32 kDa (DARPP-32) as a potential target to treat various forms of substance abuse. Despite the proven involvement of DARPP-32 in addiction pathophysiology, no robust investigations into compounds that could pharmacologically modulate it have been carried out. Agents capable of altering DARPP-32 signalling in this way could prevent or reverse drug abuse and improve upon currently substandard treatment options.

Rewarding effect of ethanol-induced conditioned place preference in mice: Effect of the monoterpenoid linalool

Alcohol addiction is a chronic relapsing disease that is progressive and has severe detrimental health outcomes. The use of natural products has become popular for the treatment of side effects of drugs and substance abuse. Linalool is a monoterpenoid that exhibits several effects on the central nervous system. Linalool was identified to have beneficial effects on different mechanisms that are relevant in drug addiction or substance use disorder. The primary aim of the present study was to evaluate the therapeutic effect of linalool on the rewarding properties of alcohol in mice. Conditioned place preference (CPP) was established by intraperitoneal (i.p.) injection of ethanol (2 g/kg) during an 8-day conditioning trial. The effects of acamprosate and linalool on the rewarding properties of ethanol were tested in mice who received linalool (12.5, 25, and 50 mg/kg, i.p.) and acamprosate (300 mg/kg, i.p.) 30 min before each ethanol injection. CPP was extinguished by repeated testing, throughout which conditioned mice were administered daily linalool. Mice were lastly examined for reinstatement provoked by i.p. administration of single low-dose ethanol (0.4 g/kg, i.p.). Treatment with linalool reduced the acquisition and reinstatement, and precipitated the extinction of ethanol-induced CPP in mice. Acquisition and reinstatement of alcohol-induced CPP were significantly reduced by acamprosate, which also precipitated extinction. Ethanol alone and the combination with linalool or acamprosate did not alter locomotor activity. The results of this study suggest that linalool may have pharmacological effects for the treatment of alcohol addiction. In addition, further investigation is required to fully explore the benefits and possible adverse effects of linalool on alcohol addiction.

Systematic review and meta-analysis of retention in treatment using medications for opioid use disorder by medication, race/ethnicity, and gender in the United States

BACKGROUND AND AIMS

There is mounting evidence that opioid use disorder is experienced differently by people of different genders and race/ethnicity groups. Similarly, in the US access to specific medications for opioid use is limited by gender and race/ethnicity. This study aims to evaluate if gender or race/ethnicity is associated with different rates of treatment retention in the US, for each of three medications used to treat opioid use disorder.

METHODS

A systematic search was conducted using PubMed, CINHAL, and PsychINFO, databases. All studies that provided a ratio of those retained in treatment at a specified time in terms of gender and/or race/ethnicity and medication were included. Variables were created to assess the effects of time in treatment, recruited sample, required attendance at concurrent psychosocial treatment, and adherence to strict rules of conduct for continuation in treatment on retention. Meta-analytical and meta-regression methods were used to compare studies on the ratio of those who completed a specific time in treatment by race/ethnicity group and by gender.

RESULTS

Nineteen articles that provided the outcome variable of interest were found (11 buprenorphine, six methadone, and two naltrexone). Meta-analyses found that treatment retention was similar for all gender and racial/ethnic groups for all three medications. Meta-regression found that those of the African American group who were recruited into buprenorphine treatment were retained significantly longer than African Americans in buprenorphine treatment who were studied retrospectively. Also, both genders had significantly lower retention in methadone treatment when there was the additional requirement of psychosocial therapy.

Abrupt cessation of reboxetine along alcohol deprivation results in alcohol intake escalation after reinstatement of drinking

Major depression (MD) is a frequent comorbidity in alcohol use disorder (AUD) patients. Antidepressant prescription is often limited by poor clinical outcomes or unwanted side effects in comorbid AUD-MD patients. Recent studies suggest that abrupt cessation of selective serotonin reuptake inhibitors antidepressant treatment increases alcohol consumption after an alcohol deprivation period in rats. However, the appearance of this effect after the treatment with selective noradrenaline reuptake inhibitors (SNRIs) is not known. Here, we report that interruption of subchronic (14 days) treatment with the SNRIs reboxetine (15 mg/kg/day intraperitoneally) resulted in escalation of ethanol intake when the animals resume alcohol self-administration. This effect of reboxetine treatment cessation was associated with a profound deactivation of the endocannabinoid/acylethanolamide signaling system in the prefrontal cortex but not in the dorsal hippocampus, as reflected by the decrease in the protein expression of the cannabinoid CB₁ receptor, the PPARα receptor, the 2-arachidonoylglycerol synthesizing enzymes DAGLα and DGALβ, and the endocanabinoid degrading enzyme MAGL. This was associated with dysregulation of the expression of glutamic acid receptors GluN1, GluA1, and mGlu5 in the medial prefrontal cortex and the dorsal hippocampus of the animals exposed to reboxetine. The present results further support the idea that abrupt cessation of antidepressant therapy along alcohol deprivation time can boost alcohol intake after relapse through mechanisms associated with endocannabinoid/glutamate signaling dysregulation. This finding might be relevant for patients suffering AUD/MD comorbidity where antidepressant therapy must be monitored with caution for avoiding unwanted side effects if adherence to the treatment is not fully achieved.

Evaluation of the Addictions Neuroclinical Assessment (ANA) framework through deep phenotyping of problem drinkers

BACKGROUND

To advance the development of a neuroscience-informed understanding of alcohol use disorder (AUD) through the Addictions Neuroclinical Assessment (ANA) framework, the present study reports on deep phenotyping of a large sample of problem drinkers.

METHODS

Participants (n = 1679) were primarily heavy drinkers with and without AUD, who completed a phenotypic battery of well-validated scales and behavioral measures of alcohol use and problems, mood, attention, and impulsivity. These scales were subjected to sequential factor analytic work in order to derive a factor solution that explains biobehavioral variation in the sample. To assess the construct validity of the resulting factor solution, scores on each factor were associated with demographic and clinical indicators.

RESULTS

Factor analysis techniques using indicators of alcohol use and problems, mood, attention, and impulsivity implicated four functional domains that compliment and extend the proposed ANA domains: negative alcohol-related consequences, incentive salience, negative emotionality, and executive function. Demographic and clinical variables significantly predicted scores on all ANA domains.

CONCLUSIONS

This study provides an independent test of the recently proposed neuroscience-based ANA framework. Results largely support the novel approach in identifying four core constructs in problem drinkers. Future studies can deepen our understanding of how these domains are relevant to AUD by incorporating biomarkers.

Types of Medication-Assisted Treatment for Opioid Use Disorder in Turkey: The Perceptions of Inpatients about Treatment Success

OBJECTIVE

The aim of this study was the following. When the different dynamics of agonist or antagonist treatments considered it is assumed that the eligible treatment to the individual may be maintained with high efficacy. Thus, we aimed to examine the difference between treatment methods, considering sociodemographics and positive perception for treatment success.

METHODS

The number of 136 individuals which their ages range between 19-50 and have been getting agonist (buprenorphine/naloxone) or antagonist (naltrexone) treatment because of opioid use disorder while resting in clinics have been evaluated to reveal the factors that may alter their perception about treatment and have been compared with sociodemographic variables and characteristics such as sociotropic and autonomic. Therefore, "Sociodemographic Data Evaluation Form," "Predictive Factors for The Addiction Treatment Success Scale," and "Sociotropy-Autonomy Scale" were used to assess the sociodemographic data, the perception towards factors which have been affected to the treatment and characteristics. The data of the individuals have been collected by the researcher via face-to-face interviews while patients were residential in the clinic.

RESULTS

According to results of our study, it has been detected that there are some differences in the perception of treatment success between individuals who have been getting agonist or antagonist treatments such as treatment method (p<0.05), treatment frequency (p<0.01) and parents' vital statuses (p<0.05).

CONCLUSION

At the end of the study it has been understood that medical and social benefits after the selection of eligible treatment methods which is suitable for individual's perception and characteristics have to be considered.

Effects of the Positive Allosteric Modulator of Metabotropic Glutamate Receptor 5, VU-29, on Maintenance Association between Environmental Cues and Rewarding Properties of Ethanol in Rats

: Metabotropic glutamate subtype 5 (mGlu5) receptors are implicated in various forms of synaptic plasticity, including drugs of abuse. In drug-addicted individuals, associative memories can drive relapse to drug use. The present study investigated the potential of the mGlu5 receptor positive allosteric modulator (PAM), VU-29 (30 mg/kg, i.p.), to inhibit the maintenance of a learned association between ethanol and environmental context by using conditioned place preference (CPP) in rats. The ethanol-CPP was established by the administration of ethanol (1.0 g/kg, i.p. × 10 days) using an unbiased procedure. Following ethanol conditioning, VU-29 was administered at various post-conditioning times (ethanol free state at the home cage) to ascertain if there was a temporal window during which VU-29 would be effective. Our experiments indicated that VU-29 did not affect the expression of ethanol-induced CPP when it was given over two post-conditioning days. However, the expression of ethanol-CPP was inhibited by 10-day home cage administration of VU-29, but not by first 2-day or last 2-day injection of VU-29 during the 10-day period. These findings reveal that VU-29 can inhibit the maintenance of ethanol-induced CPP, and that treatment duration contributes to this effect of VU-29. Furthermore, VU-29 effect was reversed by pretreatment with either MTEP (the mGlu5 receptor antagonist), or MK-801 (the N-methyl-D-aspartate-NMDA receptor antagonist). Thus, the inhibitory effect of VU-29 is dependent on the functional interaction between mGlu5 and NMDA receptors. Because a reduction in ethanol-associated cues can reduce relapse, mGlu5 receptor PAM would be useful for therapy of alcoholism. Future research is required to confirm the current findings.

[Addictive behaviors: Clinical facts]

Malgré les fréquentes comorbidités psychiatriques, le trouble de l’usage de substance doit être appréhendé comme une pathologie autonome par ses déterminants, sa sémiologie et ses modalités évolutives spontanées ou sous traitement. De multiples produits de synthèse sont désormais accessibles via internet : associé à la créativité des chimistes cela a participé à l’émergence de pratiques inédites allant du chemsex au purple drank. Les conduites addictives résultent d’un ensemble de facteurs individuels (vulnérabilités biologique et psychique) et contextuels (disponibilité et banalisation du toxique dans l’environnement). Les pathologies mentales autres sont des facteurs de vulnérabilité à la pathologie addictive, tout comme les conduites addictives peuvent révéler une pathologie émotionnelle ou psychotique. Le médecin se doit d’entendre l’impuissance du malade face au besoin irrépressible de consommer (craving) et proposer une thérapeutique qui peut être chimique (y compris traitement de substitution) et psychologique. Dans la majorité des cas, un accompagnement social s’impose pour corriger les effets désocialisants du trouble de l’usage de substances ou des comportements addictifs.

Pharmacotherapeutic management of co-morbid alcohol and opioid use

Opioid use disorder (OUD) and alcohol use disorder (AUD) are two highly prevalent substance-related disorders worldwide. Co-use of the substances is also quite prevalent, yet there are no pharmacological treatment approaches specifically designed to treat co-morbid OUD and AUD. Here, the authors critically summarize OUD, AUD and opioid/alcohol co-use and their current pharmacotherapies for treatment. They also review the mechanisms of action of opioids and alcohol within the brain reward circuitry and discuss potential combined mechanisms of action and resulting neuroadaptations. Pharmacotherapies that aim to treat AUD or OUD that may be beneficial in the treatment of co-use are also highlighted. Preclinical models assessing alcohol and opioid co-use remain sparse. Lasting neuroadaptations in brain reward circuits caused by co-use of alcohol and opioids remains largely understudied. In order to fully understand the neurobiological underpinnings of alcohol and opioid co-use and develop efficacious pharmacotherapies, the preclinical field must expand its current experimental paradigms of 'single drug' use to encompass polysubstance use. Such studies will provide insights on the neural alterations induced by opioid and alcohol co-use, and may help develop novel pharmacotherapies for individuals with co-occurring alcohol and opioid use disorders.

Nalmefene in alcohol-dependent patients with a high drinking risk: Randomized controlled trial

AIMS

Reducing alcohol consumption is one treatment approach for alcohol-dependent patients. This study compared nalmefene 20 mg and 10 mg with placebo, combined with psychosocial support, in alcohol-dependent Japanese patients with a high or very high drinking risk level (DRL).

METHODS

This was a multicenter, randomized, double-blind, phase 3 study conducted in alcohol-dependent patients with a high or very high DRL. Patients were randomized to 24 weeks of treatment with as-needed nalmefene 20 mg, 10 mg, or placebo with psychosocial support. The primary endpoint was change in heavy drinking days (HDD) from baseline to week 12. A key secondary endpoint was the change in total alcohol consumption (TAC) from baseline to week 12.

RESULTS

At week 12, 234, 206, and 154 patients who received placebo, nalmefene 20 mg, and 10 mg were included in the primary endpoint analysis. Compared with placebo, nalmefene was associated with significant reductions in HDD at week 12 (difference in 20 mg group, -4.34 days/month; 95% confidence interval [CI]: -6.05 to -2.62; P < 0.0001; difference in 10 mg group, -4.18 days/month; 95%CI: -6.05 to -2.32; P < 0.0001), as well as a significant reduction in TAC at week 12 (P < 0.0001). The incidence of treatment-emergent adverse events was 87.9%, 84.8%, and 79.2% in the groups receiving nalmefene 20 mg, 10 mg, and placebo, respectively. These events were mostly of mild or moderate severity.

CONCLUSIONS

Nalmefene 20 mg or 10 mg effectively reduced alcohol consumption and was well tolerated in alcohol-dependent patients with a high or very high DRL.

What place for prolonged-release buprenorphine depot-formulation Buvidal® in the treatment arsenal of opioid dependence? Insights from the French experience on buprenorphine

Introduction: Since the 1990s, opioid maintenance treatments (OMTs), i.e. mostly methadone and buprenorphine, have represented the therapeutic cornerstone of opioid dependence. In France, the public health strategy on opioid dependence, identified here as the 'French model', has consisted of offering a facilitated access to buprenorphine, to reach a large treatment coverage and reduce opioid-related mortality. Areas covered: Recently, a new formulation of subcutaneous buprenorphine depot (Buvidal®) has been approved in Europe for treatment of opioid dependence. The place of Buvidal® among the pre-existing arsenal of OMTs is discussed in the light of the pharmacological specificities of this new formulation, and with the particular standpoint of the French model on opioid dependence. Expert opinion: Buvidal® could constitute a promising treatment option mainly in case of: 1) OMT initiation, including in non-specialized addiction medicine care; 2) Discharge from prison or hospital; Diversion/misuse of 3) buprenorphine or 4) methadone; 5) Clinically stabilized patients wishing to avoid daily oral taking of the medication. As such, this new formulation should be highly accessible, which will require specific pathways through care as the product is intended to be administered by a healthcare professional.

Development and Psychometric Assessment of the Methadone Therapy Experiences Questionnaire among Patients under Treatment

BACKGROUND

Patient experiences play an important role in the quality of health care and gathering patients' experiences is common as part of quality measurement in health care. The present study was carried out with the aim of developing and psychometric analysis of the methadone therapy experiences questionnaire among patients under treatment with methadone.

METHODS

This cross-sectional study was performed in 2018 and 200 patients referred to the addiction treatment clinics in Kerman, Iran, participated in this study. The convenient sampling method was employed. The validity was assessed using the opinions of 50 individuals similar to the target population and 8 experts. In addition, the Cronbach's alpha coefficient was utilized to examine the test-retest reliability. Data were analyzed using descriptive and inferential statistics in the SPSS software.

FINDINGS

The face validity of the questionnaire was acceptable in the present study and the values for content validity were higher than 0.79, indicating the appropriate content validity of the questionnaire [content validity index (CVI) = 0.82 and content validity ratio (CVR) = 0.83]. Moreover, the results confirmed the reliability or reproducibility of the questionnaire (Cronbach's alpha = 0.83).

CONCLUSION

The methadone therapy experiences questionnaire was of a good validity and reliability among the patients. In the clinical area, the psychiatrists, psychologists, authorities, and staff in addiction treatment clinics can identify the quality of treatment and its strengths and weaknesses using this questionnaire.

Progress in agonist therapy for substance use disorders: Lessons learned from methadone and buprenorphine

Substance use disorders (SUD) are serious public health problems worldwide. Although significant progress has been made in understanding the neurobiology of drug reward and the transition to addiction, effective pharmacotherapies for SUD remain limited and a majority of drug users relapse even after a period of treatment. The United States Food and Drug Administration (FDA) has approved several medications for opioid, nicotine, and alcohol use disorders, whereas none are approved for the treatment of cocaine or other psychostimulant use disorders. The medications approved by the FDA for the treatment of SUD can be divided into two major classes - agonist replacement therapies, such as methadone and buprenorphine for opioid use disorders (OUD), nicotine replacement therapy (NRT) and varenicline for nicotine use disorders (NUD), and antagonist therapies, such as naloxone for opioid overdose and naltrexone for promoting abstinence. In the present review, we primarily focus on the pharmacological rationale of agonist replacement strategies in treatment of opioid dependence, and the potential translation of this rationale to new therapies for cocaine use disorders. We begin by describing the neural mechanisms underlying opioid reward, followed by preclinical and clinical findings supporting the utility of agonist therapies in the treatment of OUD. We then discuss recent progress of agonist therapies for cocaine use disorders based on lessons learned from methadone and buprenorphine. We contend that future studies should identify agonist pharmacotherapies that can facilitate abstinence in patients who are motivated to quit their illicit drug use. Focusing on those that are able to achieve abstinence from cocaine will provide a platform to broaden the effectiveness of medication and psychosocial treatment strategies for this underserved population. This article is part of the Special Issue entitled 'New Vistas in Opioid Pharmacology'.

Dopamine and addiction: what have we learned from 40 years of research

Among the neurotransmitters involved in addiction, dopamine (DA) is clearly the best known. The critical role of DA in addiction is supported by converging evidence that has been accumulated in the last 40 years. In the present review, first we describe the dopaminergic system in terms of connectivity, functioning and involvement in reward processes. Second, we describe the functional, structural, and molecular changes induced by drugs within the DA system in terms of neuronal activity, synaptic plasticity and transcriptional and molecular adaptations. Third, we describe how genetic mouse models have helped characterizing the role of DA in addiction. Fourth, we describe the involvement of the DA system in the vulnerability to addiction and the interesting case of addiction DA replacement therapy in Parkinson's disease. Finally, we describe how the DA system has been targeted to treat patients suffering from addiction and the result obtained in clinical settings and we discuss how these different lines of evidence have been instrumental in shaping our understanding of the physiopathology of drug addiction.