Naltrexone moderates the relationship between cue-induced craving and subjective response to methamphetamine in individuals with methamphetamine use disorder

Multiple comparison of different noninvasive brain stimulation and pharmacologic interventions in patients with methamphetamine use disorders: A network meta-analysis of randomized controlled trials

AIM

In recent decades, the prevalence of amphetamine and methamphetamine use disorders has at least doubled in some regions/countries, with accompanying high risks of drug overdose-associated mortality. Noninvasive brain stimulation (NIBS) methods may be effective treatments. However, the comparative efficacy of the NIBS protocol for amphetamine/methamphetamine use disorder (AUD/MUD) remains unknown to date. The aim of this network meta-analysis (NMA) was to compare the efficacy and acceptability of various NIBS methods/protocols for AUD/MUD management.

METHODS

A frequentist model-based NMA was conducted. We included randomized controlled trials (RCTs) that investigated the efficacy of NIBS and guideline-recommended pharmacologic treatments to reduce craving severity in patients with either AUD or MUD.

RESULTS

Twenty-two RCTs including 1888 participants met the eligibility criteria. Compared with the sham/placebo group (study = 19, subjects = 891), a combination of intermittent theta burst stimulation over the left dorsolateral prefrontal cortex (DLPFC) and continuous TBS over the left ventromedial prefrontal cortex (study = 1, subjects = 19) was associated with the largest decreases in craving severity [standardized mean difference (SMD) = -1.50; 95% confidence intervals (95%CIs) = -2.70 to -0.31]. High-frequency repetitive transcranial magnetic stimulation over the left DLPFC was associated with the largest improvements in depression and quality of sleep (study = 3, subjects = 86) (SMD = -2.48; 95%CIs = -3.25 to -1.71 and SMD = -2.43; 95%CIs = -3.38 to -1.48, respectively). The drop-out rate of most investigated treatments did not significantly differ between groups.

CONCLUSION

The combined TBS protocol over the prefrontal cortex was associated with the greatest improvement in craving severity. Since few studies were available for inclusion, additional large-scale randomized controlled trials are warranted.

Comparative Effectiveness Associated With Buprenorphine and Naltrexone in Opioid Use Disorder and Cooccurring Polysubstance Use

IMPORTANCE

Despite prevalent polysubstance use, treatment patterns and outcomes for individuals with opioid use disorder (OUD) and cooccurring substance use disorders (SUD) are understudied.

OBJECTIVE

To evaluate the distribution of buprenorphine and naltrexone initiation among individuals with OUD with vs without cooccurring SUD and to assess the comparative effectiveness associated with buprenorphine and naltrexone against drug-related poisonings.

DESIGN, SETTING, AND PARTICIPANTS

This observational comparative effectiveness study used insurance claims from 2011 to 2016 from the US IBM MarketScan databases to study initiation of medications for OUD (MOUD) among treatment-seeking individuals aged 12 to 64 years with a primary diagnosis of OUD. Cooccurring SUD was defined as SUD diagnosed concurrent with or in the 6 months prior to OUD treatment initiation. Treatment was codified as psychosocial treatment without MOUD or initiation or buprenorphine or naltrexone (including extended-release or oral). Methadone recipients were excluded from analysis. Data were analyzed from February 3, 2021, through February 26, 2022.

EXPOSURES

MOUD.

MAIN OUTCOMES AND MEASURES

Associations between cooccurring SUD diagnoses with treatment type were assessed with multivariable regression. The association of drug-related poisoning admissions with days covered with buprenorphine or naltrexone prescriptions vs days without prescriptions was assessed among MOUD initiators. Odds ratios from within-person fixed effects models were estimated as a function of MOUD and stratified by cooccurring SUDs.

RESULTS

Among 179 280 individuals with OUD (mean [SD] age, 33.2 [11.0] years; 90 196 [50.5%] men), 102 930 (57.4%) received psychosocial treatment without MOUD. Across 47 488 individuals with cooccurring SUDs, 33 449 (70.4%) did not receive MOUD, whereas across 131 792 individuals without cooccurring SUDs, 69 481 (52.7%) did not receive MOUD. Cooccurring SUD was associated with decreased odds of initiating buprenorphine (risk ratio [RR], 0.55 [95% CI, 0.54-0.56]) but increased odds of initiating naltrexone (extended release: RR, 1.12 [95% CI, 1.05-1.20]; oral: RR, 1.95 [95% CI, 1.86-2.03]). Among 12 485 individuals initiating MOUD who experienced at least 1 drug-related poisoning during insurance enrollment, buprenorphine treatment days were associated with decreased poisonings compared with days without MOUD for individuals with cooccurring SUD (odds ratio [OR], 0.56 [95% CI, 0.48-0.65]) and individuals without cooccurring SUD (OR, 0.57 [95% CI, 0.53-0.63]), with comparable associations observed for extended-release naltrexone. No protective association was observed for oral naltrexone.

CONCLUSIONS AND RELEVANCE

These findings suggest that individuals with OUD and polysubstance use were less likely to initiate buprenorphine and naltrexone than individuals without polysubstance use. Among individuals initiating MOUD, polysubstance use was associated with decreased buprenorphine and increased naltrexone initiation, despite buprenorphine's protective associations against drug-related poisoning.

Assessing methamphetamine-related cue reactivity in people with methamphetamine use disorder relative to controls

Methamphetamine use disorder involves methamphetamine-related cues invoking intense craving leading to relapse. Such cue reactivity is thought to arise from Pavlovian conditioning that occurs during the drug-taking experience. Cue reactivity then should be selective to methamphetamine cues (and not other cues), and not observed in people who have never experienced methamphetamine. However, these premises have never been tested and reported using objective measures such as skin conductance response (SCR). The primary aim of this study was to test these premises using a cue reactivity paradigm we developed using control cues. The secondary aim was to explore the relationship between cue reactivity, drug use characteristics, and cognition. Thirty people with a current diagnosis of methamphetamine use disorder and 30 matched controls with no history of substance use disorder were recruited. We observed higher overall subjective reactivity (F = 62.810; p < 0.001) and cue-selective physiological reactivity (F = 5.160; p = 0.026) in people with methamphetamine use disorder but not in controls. Co-morbid sedative use was associated with higher subjective craving (r = 0.521; p = 0.003). People who use methamphetamine intravenously had higher cue-selective SCR than smokers (t = 3.750; p < 0.001). Low inhibitory control measured by the Stroop task was associated with increased craving across the cue paradigm (r = -0.494; p = 0.006). Overall, these results support that cue reactivity in people with methamphetamine use disorder is due to Pavlovian conditioning. Its association with drug use and cognition highlights cue reactivity paradigm's utility in understanding methamphetamine use disorder to develop new treatments targeting cue-induced craving.

Bupropion and Naltrexone in Methamphetamine Use Disorder

BACKGROUND

The use of naltrexone plus bupropion to treat methamphetamine use disorder has not been well studied.

METHODS

We conducted this multisite, double-blind, two-stage, placebo-controlled trial with the use of a sequential parallel comparison design to evaluate the efficacy and safety of extended-release injectable naltrexone (380 mg every 3 weeks) plus oral extended-release bupropion (450 mg per day) in adults with moderate or severe methamphetamine use disorder. In the first stage of the trial, participants were randomly assigned in a 0.26:0.74 ratio to receive naltrexone-bupropion or matching injectable and oral placebo for 6 weeks. Those in the placebo group who did not have a response in stage 1 underwent rerandomization in stage 2 and were assigned in a 1:1 ratio to receive naltrexone-bupropion or placebo for an additional 6 weeks. Urine samples were obtained from participants twice weekly. The primary outcome was a response, defined as at least three methamphetamine-negative urine samples out of four samples obtained at the end of stage 1 or stage 2, and the weighted average of the responses in the two stages is reported. The treatment effect was defined as the between-group difference in the overall weighted responses.

RESULTS

A total of 403 participants were enrolled in stage 1, and 225 in stage 2. In the first stage, 18 of 109 participants (16.5%) in the naltrexone-bupropion group and 10 of 294 (3.4%) in the placebo group had a response. In the second stage, 13 of 114 (11.4%) in the naltrexone-bupropion group and 2 of 111 (1.8%) in the placebo group had a response. The weighted average response across the two stages was 13.6% with naltrexone-bupropion and 2.5% with placebo, for an overall treatment effect of 11.1 percentage points (Wald z-test statistic, 4.53; P<0.001). Adverse events with naltrexone-bupropion included gastrointestinal disorders, tremor, malaise, hyperhidrosis, and anorexia. Serious adverse events occurred in 8 of 223 participants (3.6%) who received naltrexone-bupropion during the trial.

CONCLUSIONS

Among adults with methamphetamine use disorder, the response over a period of 12 weeks among participants who received extended-release injectable naltrexone plus oral extended-release bupropion was low but was higher than that among participants who received placebo. (Funded by the National Institute on Drug Abuse and others; ADAPT-2 ClinicalTrials.gov number, NCT03078075.).

A Scoping Review on Cue Reactivity in Methamphetamine Use Disorder

The experience of craving via exposure to drug-related cues often leads to relapse in drug users. This study consolidated existing empirical evidences of cue reactivity to methamphetamine to provide an overview of current literature and to inform the directions for future research. The best practice methodological framework for conducting scoping review by Arkey and O'Malley was adopted. Studies that have used a cue paradigm or reported on cue reactivity in persons with a history of methamphetamine use were included. Databases such as Medline, EMBASE, PsycINFO and CINAHL were searched using key terms, in addition to citation check and hand search. The search resulted in a total of 32 original research articles published between 2006 to 2020. Three main themes with regard to cue reactivity were identified and synthesized: (1) effects of cue exposure, (2) individual factors associated with cue reactivity, and (3) strategies that modulate craving or reactivity to cues. Exposure to methamphetamine-associated cues elicits significant craving and other autonomic reactivity. Evidence suggests that drug cue reactivity is strongly associated with indices of drug use and other individual-specific factors. Future studies should focus on high quality studies to support evidence-based interventions for reducing cue reactivity and to examine cue reactivity as an outcome measure.

Neuroplastic changes in resting-state functional connectivity after rTMS intervention for methamphetamine craving

Amphetamine-type stimulants are the second most commonly abused illicit drug worldwide, with no effective medical treatments currently available. Previous studies have demonstrated that high frequency repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral prefrontal cortex (DLPFC) reduced cue-induced craving in patients with methamphetamine dependence. However, the neuroplastic mechanism underlying rTMS intervention in methamphetamine users remains to be elucidated. Sixty participants (40 males) with severe methamphetamine use disorder according to DSM-5 were randomized to receive either intermittent theta burst protocols (iTBS) (short bursts of 50 Hz rTMS repeated at a rate in the theta range (5 Hz), 2-sec on, 8-sec off for 5 min; 900 pulses) or sham rTMS over the DLPFC over four weeks (20 daily sessions). Resting state functional connectivity magnetic resonance imaging was acquired before and after rTMS intervention. Participants received drug related cue exposure and rated their craving before and after stimulation. Seed-based functional connectivity analysis was performed to probe rTMS-induced neuroplastic reorganization of brain functional networks. Results showed that twenty daily rTMS sessions decreased craving, increased functional connectivity between left DLPFC and inferior parietal lobule, and decreased functional connectivity between insula and inferior parietal lobule, medial temporal lobe and precuneus. Moreover, the increase of functional connectivity between DLPFC and inferior parietal lobule correlated with craving reduction. This study suggests that neuroplastic changes of frontoparietal functional connectivity contributes to craving reduction, shedding light on the therapeutic effect of rTMS on methamphetamine use disorder. This article is part of the special issue on Stress, Addiction and Plasticity.

Drug-Induced Craving for Methamphetamine Is Associated With Neural Methamphetamine Cue Reactivity

OBJECTIVE

Drug craving serves as the major motivator to propagate drug use and is thought to elicit relapse in abstinent individuals. Although craving for methamphetamine has been investigated using both laboratory and neuroimaging methodologies, the relationship between drug-induced craving and neural responses to methamphetamine cues has yet to be explored. Therefore, the present study investigated whether methamphetamine-induced craving responses in the laboratory were associated with neural response to methamphetamine cues.

METHOD

Non-treatment-seeking individuals with methamphetamine use disorder (n = 15) completed two sessions, one in the laboratory where they underwent a methamphetamine infusion, and one in the magnetic resonance imaging scanner where they viewed methamphetamine cues. Participants reported their craving for methamphetamine over the course of the laboratory session. Analyses examined the association between peak ratings of methamphetamine-induced craving and neural activation to methamphetamine cues.

RESULTS

In individuals with a methamphetamine use disorder, methamphetamine-induced craving was positively associated with neural methamphetamine cue reactivity in the precuneus, putamen, and ventromedial prefrontal cortex (Z > 2.3, p < .05).

CONCLUSIONS

There is a shared neurobiology underlying cue- and drug-induced craving in individuals with methamphetamine use disorder. Treatments that disrupt this circuitry may decrease craving and help prevent relapse.

Methamphetamine Use: A New Wave in the Opioid Crisis?

BACKGROUND

The ongoing drug crisis in the United States continues to be headlined with numbers of deaths related to opioid overdose. Less known to the public and health care providers is the rise in methamphetamine use, often in conjunction with opioids or adulterated with fentanyl. An old practice with a new twist is the use of methamphetamine in conjunction with an opioid such as heroin.

PURPOSE

Although there are no Food and Drug Administration-approved medications to treat individuals with stimulant use disorders, a review of available studies suggests a few promising medications that may be helpful for patients in early recovery from methamphetamine.

OUTCOME

Some individuals are more likely to respond to medications such as long-acting naltrexone, bupropion, and mirtazapine, who have light-to-moderate use of methamphetamine. Naloxone kits should be considered for all patients who are actively using stimulants because of a high potential of adulterated methamphetamine.

Endogenous opiates and behavior: 2017

This paper is the fortieth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2017 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

The role of the opioid system in decision making and cognitive control: A review

The opioid system regulates affective processing, including pain, pleasure, and reward. Restricting the role of this system to hedonic modulation may be an underestimation, however. Opioid receptors are distributed widely in the human brain, including the more "cognitive" regions in the frontal and parietal lobes. Nonhuman animal research points to opioid modulation of cognitive and decision-making processes. We review emerging evidence on whether acute opioid drug modulation in healthy humans can influence cognitive function, such as how we choose between actions of different values and how we control our behavior in the face of distracting information. Specifically, we review studies employing opioid agonists or antagonists together with experimental paradigms of reward-based decision making, impulsivity, executive functioning, attention, inhibition, and effort. Although this field is still in its infancy, the emerging picture suggests that the mu-opioid system can influence higher-level cognitive function via modulation of valuation, motivation, and control circuits dense in mu-opioid receptors, including orbitofrontal cortex, basal ganglia, amygdalae, anterior cingulate cortex, and prefrontal cortex. The framework that we put forward proposes that opioids influence decision making and cognitive control by increasing the subjective value of reward and reducing aversive arousal. We highlight potential mechanisms that might underlie the effects of mu-opioid signaling on decision making and cognitive control and provide directions for future research.

Drug-Induced Craving for Methamphetamine Is Associated With Neural Methamphetamine Cue Reactivity

OBJECTIVE

Drug craving serves as the major motivator to propagate drug use and is thought to elicit relapse in abstinent individuals. Although craving for methamphetamine has been investigated using both laboratory and neuroimaging methodologies, the relationship between drug-induced craving and neural responses to methamphetamine cues has yet to be explored. Therefore, the present study investigated whether methamphetamine-induced craving responses in the laboratory were associated with neural response to methamphetamine cues.

METHOD

Non-treatment-seeking individuals with methamphetamine use disorder (n = 15) completed two sessions, one in the laboratory where they underwent a methamphetamine infusion, and one in the magnetic resonance imaging scanner where they viewed methamphetamine cues. Participants reported their craving for methamphetamine over the course of the laboratory session. Analyses examined the association between peak ratings of methamphetamine-induced craving and neural activation to methamphetamine cues.

RESULTS

In individuals with a methamphetamine use disorder, methamphetamine-induced craving was positively associated with neural methamphetamine cue reactivity in the precuneus, putamen, and ventromedial prefrontal cortex (Z > 2.3, p < .05).

CONCLUSIONS

There is a shared neurobiology underlying cue- and drug-induced craving in individuals with methamphetamine use disorder. Treatments that disrupt this circuitry may decrease craving and help prevent relapse.

Effects of Naltrexone on Large-Scale Network Interactions in Methamphetamine Use Disorder

Naltrexone attenuates craving, and the subjective effects of methamphetamine and extended-release naltrexone (XR-NTX) reduces functional connectivity between regions of the striatum and limbic cortex. Naltrexone modulates neural activity at dopaminergic synapses; however, it is unclear whether naltrexone has an effect on large-scale brain networks. Functional networks interact to coordinate behavior, and as substance-use disorders are associated with an imbalance between reward and cognitive control networks, treatment approaches that target interactive brain systems underlying addiction may be a useful adjunct for behavioral therapies. The objective of this study was to examine the effect of XR-NTX on large-scale brain networks and to determine whether changes in network relationships attenuate drug use, craving, and addiction severity. Thirty-nine participants in or seeking treatment for methamphetamine-use disorder were enrolled in a clinical trial of XR-NTX between May 2013 and March 2015 (Clinicaltrials.gov NCT01822132). Functional magnetic resonance imaging (fMRI) and questionnaires were conducted before and after double-blinded randomization to a 4-week injection of XR-NTX or placebo. In the XR-NTX group, methamphetamine use was reduced along with a decrease in the coupling between executive control (ECN) and default mode (DMN) networks. As decoupling of ECN and DMN networks was associated with change in the severity of dependence, the results suggest that XR-NTX may modulate and enhance ECN attentional resources and suppress DMN self-referential and emotional processing. This study identifies the effect of naltrexone on changes in the intrinsic functional coupling of large-scale brain networks and provides a more systematic understanding of how large-scale networks interact to promote behavioral change in methamphetamine-use disorder.

Efficacy and safety of naltrexone for amfetamine and methamfetamine use disorder: a systematic review of randomized controlled trials

INTRODUCTION

Amfetamine and methamfetamine abuse remains a prevalent health problem, increasing the burden on healthcare. Naltrexone, a µ-opioid receptor antagonist, has been suggested as a promising treatment for amfetamine and methamfetamine use disorder.

OBJECTIVE

To review the current evidence for the efficacy and safety of naltrexone as a pharmacological treatment for amfetamine and methamfetamine use disorder. The primary outcome was defined as abstinence or reduction of use. Secondary outcomes were, attenuated "positive" subjective effects (e.g., "feel good," "craving," etc.) of amfetamine or methamfetamine after naltrexone treatment, adverse events and physiological changes (e.g., blood pressure, heart rate).

METHODS

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A systematic literature search was conducted on 2 April 2017, and updated on 31 March 2018. Records were retrieved from databases including PubMed, EMBASE Classic plus EMBASE 1980 via Ovid, and the databases were searched using keywords and/or headings: (naltrexone AND amfetamine AND dependence) OR (naltrexone AND amfetamine AND craving) OR (vivitrol AND amfetamine) OR (revia AND amfetamine) OR (naltrexone AND amfetamine) OR (naltrexone AND methamfetamine dependence) OR (naltrexone AND methamfetamine AND craving) OR (vivitrol AND methamfetamine) OR (revia AND methamfetamine) OR (naltrexone AND ice) OR (naltrexone AND crystal meth) OR (naltrexone AND methamfetamine). Studies investigating the effects of naltrexone on amfetamine or methamfetamine use were eligible for inclusion. All studies were rated as low risk of bias using the Cochrane tool for risk of bias.

RESULTS

Among 591 identified studies, there were four randomized controlled trials. Two studies investigated the effects of naltrexone on amfetamine use disorder and two on methamfetamine use. Compared to placebo, the abstinence rate was increased significantly (p < 0.05) by naltrexone in one of two amfetamine studies, whereas there was no statistical difference in the only study reporting methamfetamine use. In one out of two amfetamine studies, naltrexone significantly attenuated either craving levels or subjective effects (e.g., "want more," "like effect") relative to placebo (p < 0.05). Additionally, only in one of two methamfetamine studies did naltrexone produce a significant reduction (p < 0.05) in craving levels or attenuated subjective effects. Both amfetamine and methamfetamine studies showed good tolerability of naltrexone, with few adverse events seen.

CONCLUSIONS

There is presently insufficient evidence to support the use of naltrexone in amfetamine and metamfetamine use disorders. There is a compelling need for high-quality studies to further evaluate the potential use of naltrexone.

A preliminary randomized clinical trial of naltrexone reduces striatal resting state functional connectivity in people with methamphetamine use disorder

OBJECTIVE

Naltrexone has been shown to attenuate craving and the subjective effects of methamphetamine. Although naltrexone has modulatory effects on neural activity at dopaminergic synapses, the effect on striatal connectivity is unclear. As methamphetamine use is associated with greater resting-state functional connectivity (RSFC) in the dopaminergic system, we examined whether extended-release naltrexone (XR-NTX) can normalize striatal connectivity and whether changes in RSFC are associated with changes in craving and methamphetamine use.

METHODS

Thirty-seven participants in or seeking treatment for methamphetamine use disorder took part in this clinical trial at a university-based research clinic between May 2013 and March 2015 (Clinicaltrials.gov NCT01822132). Participants were randomized by a random number generator to a single four-week injection of XR-NTX or placebo. Functional magnetic resonance imaging (fMRI) and self-reported measures of craving and methamphetamine use were conducted before and after double-blinded randomization.

FINDINGS

There was a significant reduction in methamphetamine use in the naltrexone group and a significant treatment-by-time interaction on RSFC between the ventral striatum, amygdala, hippocampus, and midbrain. Connectivity was significantly reduced over time in participants randomized to naltrexone but unchanged in those randomized to placebo (p < 0.05, whole-brain corrected). Interactions between treatment and changes in connectivity show that significant reductions in connectivity were associated with reductions in methamphetamine use.

CONCLUSIONS

Neurobiological deficits associated with methamphetamine use may undermine the efficacy of pharmacotherapies that directly target the dopamine reward system. Naltrexone, via antagonism of indirect mu-opioid effects on dopamine neurons, may attenuate reward system connectivity and aid in methamphetamine use treatment.