Unveiling the link between chronic pain and misuse of opioids and cannabis

Over 50 million Americans endure chronic pain where many do not receive adequate treatment and self-medicate to manage their pain by taking substances like opioids and cannabis. Research has shown high comorbidity between chronic pain and substance use disorders (SUD) and these disorders share many common neurobiological underpinnings, including hypodopaminergic transmission. Drugs commonly used for self-medication such as opioids and cannabis relieve emotional, bothersome components of pain as well as negative emotional affect that perpetuates misuse and increases the risk of progressing towards drug abuse. However, the causal effect between chronic pain and the development of SUDs has not been clearly established. In this review, we discuss evidence that affirms the proposition that chronic pain is a risk factor for the development of opioid and cannabis use disorders by outlining the clinical evidence and detailing neurobiological mechanisms that link pain and drug misuse. Central to the link between chronic pain and opioid and cannabis misuse is hypodopaminergic transmission and the modulation of dopamine signaling in the mesolimbic pathway by opioids and cannabis. Moreover, we discuss the role of kappa opioid receptor activation and neuroinflammation in the context of dopamine transmission, their contribution to opioid and cannabis withdrawal, along with potential new treatments.

Substance Use Disorder

Substance use disorders (SUDs) present a challenge in the emergency department (ED) setting. This article provides an overview of SUDs, their clinical assessment, legal considerations in drug testing, diagnosis, and treatment approaches. SUDs are prevalent and coexist with mental health disorders, necessitating comprehensive evaluation and management. Clinical assessment involves screening tools, substance use history, and identification of comorbidities. Diagnosis relies on a thorough evaluation of substance abuse patterns and associated medical conditions. Treatment approaches encompass a multidisciplinary approach, incorporating counseling, medications, and social support. Effective management of SUDs in the ED requires a comprehensive understanding of these complex disorders.

Prevalence and determinants of opioid use disorder among long-term opiate users in Golestan Cohort Study

BACKGROUND

Number of opiate users worldwide has doubled over the past decade, but not all of them are diagnosed with opioid use disorder. We aimed to identify the prevalence and risk factors for OUD after ten years of follow-up.

METHODS

Among 8,500 chronic opiate users at Golestan Cohort Study baseline (2004-2008), we recalled a random sample of 451 subjects in 2017. We used three questionnaires: a questionnaire about current opiate use including type and route of use, the drug use disorder section of the Composite International Diagnostic Interview lifetime version, and the validated Kessler10 questionnaire. We defined opioid use disorder and its severity based on the DSM-5 criteria and used a cutoff of 12 on Kessler10 questionnaire to define psychological distress.

RESULTS

Mean age was 61.2 ± 6.6 years (84.7% males) and 58% were diagnosed with opioid use disorder. Starting opiate use at an early age and living in underprivileged conditions were risk factors of opioid use disorder. Individuals with opioid use disorder were twice likely to have psychological distress (OR = 2.25; 95%CI: 1.44-3.52) than the users without it. In multivariate regression, former and current opiate dose and oral use of opiates were independently associated with opioid use disorder. Each ten gram per week increase in opiate dose during the study period almost tripled the odds of opioid use disorder (OR = 3.18; 95%CI: 1.79-5.63).

CONCLUSIONS

Chronic opiate use led to clinical opioid use disorder in more than half of the users, and this disorder was associated with psychological distress, increasing its physical and mental burden in high-risk groups.

Decreased myelin-related gene expression in the nucleus accumbens during spontaneous neonatal opioid withdrawal in the absence of long-term behavioral effects in adult outbred CFW mice

Prenatal opioid exposure is a major health concern in the United States, with the incidence of neonatal opioid withdrawal syndrome (NOWS) escalating in recent years. NOWS occurs upon cessation of in utero opioid exposure and is characterized by increased irritability, disrupted sleep patterns, high-pitched crying, and dysregulated feeding. The main pharmacological strategy for alleviating symptoms is treatment with replacement opioids. The neural mechanisms mediating NOWS and the long-term neurobehavioral effects are poorly understood. We used a third trimester-approximate model in which neonatal outbred pups (Carworth Farms White; CFW) were administered once-daily morphine (15 mg/kg, s.c.) from postnatal day (P) day 1 through P14 and were then assessed for behavioral and transcriptomic adaptations within the nucleus accumbens (NAc) on P15. We also investigated the long-term effects of perinatal morphine exposure on adult learning and reward sensitivity. We observed significant weight deficits, spontaneous thermal hyperalgesia, and altered ultrasonic vocalization (USV) profiles following repeated morphine and during spontaneous withdrawal. Transcriptome analysis of NAc from opioid-withdrawn P15 neonates via bulk mRNA sequencing identified an enrichment profile consistent with downregulation of myelin-associated transcripts. Despite the neonatal behavioral and molecular effects, there were no significant long-term effects of perinatal morphine exposure on adult spatial memory function in the Barnes Maze, emotional learning in fear conditioning, or in baseline or methamphetamine-potentiated reward sensitivity as measured via intracranial self-stimulation. Thus, the once daily third trimester-approximate exposure regimen, while inducing NOWS model traits and significant transcriptomic effects in neonates, had no significant long-term effects on adult behaviors.

A case of false positive opiate immunoassay results from rifampin (rifampicin) treatment

The drug screen test on a 12-year-old male patient was positive for opiates by a kinetic interaction of microparticles in solution (KIMS) immunoassay method on the Roche Cobas C502. The positive opiates result was not confirmed by the liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. A chart review revealed that the patient had tuberculosis and was on rifampin. We spiked rifampin into drug-free urine and tested opiates with the Cobas method. Once again, a positive result was obtained. This case showed that rifampin can still cause false positive opiate results measured with the KIMS method. We want to stress the importance of confirming positive screen results by more specific methods such as LC-MS/MS.

CHANTER Syndrome and mesenteric ischemia presenting concurrently, a case report and literature review

We present a case of a 70-year-old male who was brought to the hospital with altered mental status and was found to have 2 serious complications of cocaine use which are Cerebellar Hippocampal and Basal Nuclei Transient Edema with Restricted diffusion (CHANTER) syndrome and mesenteric ischemia. CHANTER syndrome is a recently described constellation of radiologic and clinical findings and has a strong association with opiates, and/or other drugs of abuse, including cocaine. Even though CHANTER has many similarities with other ischemic, anoxic, and/or toxic injuries related to substance abuse such as clinical presentation and restricted diffusion on magnetic resonance imaging (MRI); the typical distribution of affected regions in the brain is helpful in differentiating from other injuries. With this study, we aim to emphasize the clues that separate CHANTER syndrome from other acute neurologic problems in the setting of substance use. Our case also suggests that the obstructive hydrocephalus, a known possible complication of CHANTER, is likely seen in the cases with severe and central cerebellar involvement. Additionally, it is not common to see complications in 2 different systems concurrently and a multisystemic approach is crucial to a patient with cocaine use to prevent missed life-threatening consequences throughout the various body systems.

Intergenerational consequences of adolescent morphine exposure on learning and memory

Drug addiction is a worldwide social and medical disorder. More than 50 percent of drug abusers start their substance abuse in adolescence between the ages of 15-19. Adolescence is a sensitive and crucial period for the development and maturity of the brain. Chronic exposure to morphine, particularly during this period, lead to long-lasting effects, including effects that extend to the next generation. The current study examined the intergenerational effects of paternal morphine exposure during adolescence on learning and memory. In this study, male Wistar rats were exposed to increasing doses of morphine (5-25 mg/kg, s.c.) or saline for 10 days at postnatal days (PND) 30-39 during adolescence. Following a 20-day drug-free period, the treated male rats were mated with naïve females. Adult male offspring (PND 60-80) were tested for working memory, novel object recognition memory, spatial memory, and passive avoidance memory using the Y-Maze, novel object recognition, Morris water maze, and shuttle box tests, respectively. The spontaneous alternation (as measured in the Y-Maze test) was significantly less in the morphine-sired group compared to the saline-sired one. The offspring showed significantly less discrimination index in the novel object recognition test when compared to the control group. Morphine-sired offspring tended to spend significantly more time in the target quadrant and less escape latency in the Morris water maze on probe day when compared to the saline-sired ones. The offspring showed significantly less step-through latency to enter the dark compartment compared to the control group when measured in the shuttle box test. Paternal exposure to morphine during adolescence impaired working, novel object recognition, and passive avoidance memory in male offspring. Spatial memory changed in the morphine-sired group compared to the saline-sired one.

Examination of methadone involved overdoses during the COVID-19 pandemic

BACKGROUND

The US opioid overdose epidemic continues to escalate. The restrictions on methadone availability including take-home dosing were loosened during the COVID-19 pandemic although there have been concerns about the high street value of diverted methadone. This report examined how fatal overdoses involving methadone have changed over the past two-decades including during the pandemic.

METHODS

The CDC's Wide-ranging Online Data for Epidemiologic Research (WONDER) was used to find the unintentional methadone related overdose death rate from 1999 to 2020. Unintentional methadone deaths were defined using the ICD X40-44 codes with only data for methadone (T40.3). Data from the DEA's Automation of Reports and Consolidated Orders System (ARCOS) on methadone overall use, opioid treatment programs use, and pain management use was gathered for all states for 2020 and corrected for population.

RESULTS

There have been dynamic changes over the past two-decades in methadone overdoses. Overdoses increased from 1999 (0.9/million) to 2007 (15.9) and declined until 2019 (6.5). Overdoses in 2020 (9.6) were 48.1% higher than in 2019 (t(50) = 3.05, p < .005). The state level correlations between overall methadone use (r(49) = +0.75, p < .001), and opioid treatment program use (r(49) = +0.77, p < .001) with overdoses were positive, strong, and statistically significant. However, methadone use for pain treatment was not associated with methadone overdoses (r(49) = -0.08).

CONCLUSIONS

Overdoses involving methadone significantly increased by 48.1% in 2020 relative to 2019. Policy changes that were implemented following the COVID-19 pandemic involving methadone take-homes may warrant further study before they are made permanent.

Systematic Identification and Categorization of Opioid Prescribing and Dispensing Policies in 16 States and Washington, DC

OBJECTIVES

State policies can impact opioid prescribing or dispensing. Some state opioid policies have been widely examined in empirical studies, including prescription drug monitoring programs and pain clinic licensure requirements. Other relevant policies might exist that have received limited attention. Our objective was to identify and categorize a wide range of state policies that could affect opioid prescribing/dispensing.

METHODS

We used stratified random sampling to select 16 states and Washington, DC, for our sample. We collected state regulations and statutes effective during 2020 from each jurisdiction, using search terms related to opioids, pain management, and prescribing/dispensing. We then conducted qualitative template analysis of the data to identify and categorize policy categories.

RESULTS

We identified three dimensions of opioid prescribing/dispensing laws: the prescribing/dispensing rule, its applicability, and its disciplinary consequences. Policy categories of prescribing/dispensing rules included clinic licensure, staff credentials, evaluating the appropriateness of opioids, limiting the initiation of opioids, preventing the diversion or misuse of opioids, and enhancing patient safety. Policy categories related to applicability of the law included the pain type, substance type, practitioner, setting, payer, and prescribing situation. The disciplinary consequences dimension included specific consequences and inspection processes.

DISCUSSION

Policy categories within each dimension of opioid prescribing/dispensing laws could become a foundation for creating variables to support empirical analyses of policy effects, improving operationalization of policies in empirical studies, and helping to disentangle the effects of multiple state laws enacted at similar times to address the opioid crisis. Several of the policy categories we identified have been underexplored in previous empirical studies.

Adolescent morphine exposure impairs dark avoidance memory and synaptic potentiation of ventral hippocampal CA1 during adulthood in rats

Adolescence is a neurobiological critical period for neurodevelopmental processes. Adolescent opioid exposure can affect cognitive abilities via regional-specific lasting changes in brain structure and function. The current study was therefore designed to assess the long-term effects of adolescent morphine exposure on dark avoidance memory and synaptic plasticity of the ventral hippocampal CA1. Adolescent Wistar rats received escalating doses of morphine for 10 days. Morphine injections were started with an incremental dose of 2.5 mg/kg to reach a dose of 25 mg/kg. 30 days after the last injection, inhibitory memory and in vitro field potential recording were evaluated. Also, the weight of the animals was measured during drug and post-drug exposure. We found that adolescent morphine exposure decreased weight gain during morphine and post-morphine exposure. Passive avoidance memory was impaired in the morphine group. Moreover, adolescent morphine exposure caused an increase in baseline synaptic responsiveness and failed long-term potentiation (LTP) in the ventral hippocampal CA1 during adulthood. In the morphine group, the mean values of the field excitatory postsynaptic potential (fEPSP) slopes required to elicit a half-maximal population spike (PS) amplitude were significantly greater than that of the saline group. Therefore, adolescent morphine exposure has a durable effect on memory functions, synaptic activity, and plasticity of ventral hippocampal CA1. Adults with adolescent morphine exposures may experience maladaptive behaviors and cognitive disabilities.

Acute morphine injection persistently affects the electrophysiological characteristics of rat locus coeruleus neurons

Administration of morphine is associated with critical complications in clinic which primarily includes the development of dependence and tolerance even following a single dose (acute) exposure. Behavioral and electrophysiological studies support the significant role of locus coeruleus (LC) neurons in tolerance and dependence following chronic morphine exposure. The current study was designed to explore the electrophysiological properties of the LC neurons following acute morphine exposure. In-vitro whole-cell patch-clamp recordings were performed in LC neurons 24 h after intraperitoneal morphine injection. Acute morphine injection significantly decreased the spontaneous firing rate of LC neurons, the rising and decay slopes of action potentials, and consequently increased the action potential duration. In addition, morphine treatment did not alter the rheobase current and first spike latency while affected the inhibitory postsynaptic currents elicited in response to orexin-A. In fact, single morphine exposure could inhibit the disinhibitory effect of orexin-A on LC neurons.

Cannabis, cocaine, methamphetamine, and opiates increase the risk of incident atrial fibrillation

AIMS

Atrial fibrillation (AF) is now regarded as a preventable disease, requiring a search for modifiable risk factors. With legalization of cannabis and more lenient laws regarding the use of other illicit substances, investigation into the potential effects of methamphetamine, cocaine, opiate, and cannabis exposure on incident AF is needed.

METHODS AND RESULTS

Using Office of Statewide Health Planning and Development databases, a longitudinal analysis was performed of adult Californians ≥18 years of age who received care in an emergency department, outpatient surgery facility, or hospital from 1 January 2005 to 31 December 2015. Associations between healthcare coding for the use of each substance and a new AF diagnosis were assessed. Among 23,561,884 patients, 98 271 used methamphetamine, 48 701 used cocaine, 10 032 used opiates, and 132 834 used cannabis. Of the total population, 998 747 patients (4.2%) developed incident AF during the study period. After adjusting for potential confounders and mediators, use of methamphetamines, cocaine, opiates, and cannabis was each associated with increased incidence of AF: hazard ratios 1.86 [95% confidence interval (CI) 1.81-1.92], 1.61 (95% CI 1.55-1.68), 1.74 (95% CI 1.62-1.87), and 1.35 (95% CI 1.30-1.40), respectively. Negative control analyses in the same cohort failed to reveal similarly consistent positive relationships.

CONCLUSION

Methamphetamine, cocaine, opiate, and cannabis uses were each associated with increased risk of developing incident AF. Efforts to mitigate the use of these substances may represent a novel approach to AF prevention.

Barriers to enrolling in voluntary treatment programs in Malaysia: a study of women who use methamphetamine (WWUM)

Women with substance use disorders (SUDs) have been widely reported to face barriers in seeking treatment. We sought to identify barriers that prevented women who use methamphetamine (WWUM) from accessing the decade-old Voluntary Treatment Centers (VTCs) in Malaysia. A total of 153 WWUM who were undergoing rehabilitation for methamphetamine use at a compulsory drug detention center (CDDC) were recruited for this cross-sectional study. Data were collected by canvasing a structured questionnaire through face-to-face meetings. Of the total sample, 131 (86%) were Malays, with a mean age of 32.1 years. The commonly cited treatment barriers were the belief that methamphetamine use was not problematic (42%), not knowing how to seek treatment (38%), feeling embarrassed to seek treatment (33%), the lack of family support (24%), and the long waiting time for enrollment (23%). Logistic analyses indicated that a longer duration of use increased the odds of not acknowledging methamphetamine use as a problem while older participants had lower odds of holding a similar view. A longer duration of use also increased the odds of claiming treatment was not needed but lowered the odds of asserting a lack of confidence in treatment. Furthermore, Malays had higher odds of lacking family support in seeking treatment while being employed lowered the odds of not wanting treatment. Addressing these concerns will hopefully encourage higher participation of WWUM in voluntary treatment programs.

Prognosis in substance abuse-related acute toxic leukoencephalopathy: A scoping review

OBJECTIVES

Abuse of opiates, cocaine, and lipophilic inhalants (e.g., toluene) can damage brain myelin and cause acute toxic leukoencephalopathy (TL), but little is known about recovery or prognosis in this condition. In light of the ongoing opiate epidemic in the United States, it is important to understand the natural history of patients who have acute neurological complications from illicit drug exposure. Our aim was to conduct a scoping review of the literature regarding prognosis in described cases of substance abuse-related TL.

METHODS

A strategic search of PubMed, Ovid, Cumulative Index to Nursing, and Allied Health Literature (CINAHL) databases yielded adult cases of acute TL from opiates, cocaine, or inhalants. Cases and case series were eligible for inclusion if they described acute leukoencephalopathy with a clear temporal association with opiate, cocaine, or inhalant abuse. Inclusion was contingent on availability of clinical descriptions until death or ≥ 4 weeks follow-up with neuroimaging consistent with TL.

RESULTS

Among 52 cases from 14 articles, 21 (40.4%) individuals died with mean time to death of 28.2 days; with mean follow-up of 12.8 months, 10 (19.2%) survived with no recovery, 17 (32.7%) had partial recovery, and 4 (7.7%) individuals had full recovery.

CONCLUSION

Substance abuse-related acute TL often has a poor prognosis, but partial or even full recovery is possible in a subgroup of individuals over months to years.

FORWARDS-1: an adaptive, single-blind, placebo-controlled ascending dose study of acute baclofen on safety parameters in opioid dependence during methadone-maintenance treatment-a pharmacokinetic-pharmacodynamic study

Background

Treatment of opiate addiction with opiate substitution treatment (e.g. methadone) is beneficial. However, some individuals desire or would benefit from abstinence but there are limited options to attenuate problems with opiate withdrawal. Preclinical and preliminary clinical evidence suggests that the GABA-B agonist, baclofen, has the desired properties to facilitate opiate detoxification and prevent relapse. This study aims to understand whether there are any safety issues in administering baclofen to opioid-dependent individuals receiving methadone.

Methods

Opiate-dependent individuals (DSM-5 severe opioid use disorder) maintained on methadone will be recruited from addiction services in northwest London (NHS and third sector providers). Participants will be medically healthy with no severe chronic obstructive pulmonary disease or type 2 respiratory failure, no current dependence on other substances (excluding nicotine), no current severe DSM-5 psychiatric disorders, and no contraindications for baclofen or 4800 IU vitamin D (placebo). Eligible participants will be randomised in a 3:1 ratio to receive baclofen or placebo in an adaptive, single-blind, ascending dose design. A Bayesian dose-escalation model will inform the baclofen dose (10, 30, 60, or 90 mg) based on the incidence of ‘dose-limiting toxicity’ (DLT) events and participant-specific methadone dose. A range of respiratory, cardiovascular, and sedative measures including the National Early Warning Score (NEWS2) and Glasgow Coma Scale will determine DLT. On the experimental day, participants will consume their usual daily dose of methadone followed by an acute dose of baclofen or placebo (vitamin D3) ~ 1 h later. Measures including oxygen saturation, transcutaneous CO₂, respiratory rate, QTc interval, subjective effects (sedation, drug liking, craving), plasma levels (baclofen, methadone), and adverse events will be obtained using validated questionnaires and examinations periodically for 5 h after dosing.

Discussion

Study outcomes will determine what dose of baclofen is safe to prescribe to those receiving methadone, to inform a subsequent proof-of-concept trial of the efficacy baclofen to facilitate opiate detoxification. To proceed, the minimum acceptable dose is 30 mg of baclofen in patients receiving ≤ 60 mg/day methadone based on the clinical experience of baclofen’s use in alcoholism and guidelines for the management of opiate dependence.

Trial registration

Clinicaltrials.gov NCT05161351. Registered on 16 December 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06821-9.

δ-Opioid receptors in primary sensory neurons tonically restrain nociceptive input in chronic pain but do not enhance morphine analgesic tolerance

δ-Opioid receptors (DORs, encoded by the Oprd1 gene) are expressed throughout the peripheral and central nervous system, and DOR stimulation reduces nociception. Previous studies suggest that DORs promote the development of analgesic tolerance of μ-opioid receptor (MOR) agonists. It is uncertain whether DORs expressed in primary sensory neurons are involved in regulating chronic pain and MOR agonist-induced tolerance. In this study, we generated Oprd1 conditional knockout (Oprd1-cKO) mice by crossing Advillin-Cre mice with Oprd1-floxed mice. DOR expression in the dorsal root ganglion was diminished in Oprd1-cKO mice. Systemic or intrathecal injection of the DOR agonist SNC-80 produced analgesia in wild-type (WT), but not Oprd1-cKO, mice. In contrast, intracerebroventricular injection of SNC-80 produced a similar analgesic effect in WT and Oprd1-cKO mice. However, morphine-induced analgesia, hyperalgesia, or analgesic tolerance did not differ between WT and Oprd1-cKO mice. Compared with WT mice, Oprd1-cKO mice showed increased mechanical and heat hypersensitivity after nerve injury or tissue inflammation. Furthermore, blocking DORs with naltrindole increased nociceptive sensitivity induced by nerve injury or tissue inflammation in WT, but not Oprd1-cKO, mice. In addition, naltrindole potentiated glutamatergic input from primary afferents to spinal dorsal horn neurons increased by nerve injury or CFA in WT mice; this effect was absent in Oprd1-cKO mice. Our findings indicate that DORs in primary sensory neurons are critically involved in the analgesic effect of DOR agonists but not morphine-induced analgesic tolerance. Presynaptic DORs at primary afferent central terminals constitutively inhibit inflammatory and neuropathic pain by restraining glutamatergic input to spinal dorsal horn neurons.

Inter-trial variability in postural control and brain activation: Effects of previous opiate abuse

There is an abundant literature demonstrating the superiority of inter-trial variability (ITV) of reaction time over mean reaction time in the early identification of subtle cognitive processing decrements. The present study extends these ideas by examining brain activation and postural control ITV among participants with versus without a history of chronic opiate abuse. Participants enrolled in opiate abuse (n = 82) and control (n = 112) groups completed tasks that challenged selective attention and balance. During the respective tasks, the inter-trial variabilities in frontal P300a electroencephalographic responses and sway strategy scores outperformed their mean levels in differentiating the groups. The relevance of several potential alternative explanations for the differences, including premorbid conduct disorder and comorbid alcohol abuse, depression, and methadone use, was discounted via simultaneous or post hoc analyses. It appears that chronic opiate abuse has adverse CNS effects that persist into the protracted abstinence period. These effects alter the temporal stability of its response to external and internal stimuli.

Take-Home Naloxone and the Prevention of Deaths from Heroin Overdose: Pursuing Strong Science, Fuller Understanding, Greater Impact

BACKGROUND AND CONTEXT

Realization of the life-saving potential of "take-home naloxone" has been a personal journey, but it has also been a collective journey. It has been a story of individual exploration and growth, and also a story of changes at a societal level. "Take-home naloxone" has matured since its first conceptualization a quarter of a century ago. It required recognition of the enormous burden of deaths from drug overdose (particularly heroin and other opioids), and also realization of critical clusterings (such as post-release from prison). It also required realization that, since many overdose deaths are witnessed, we can potentially prevent many deaths by mobilizing drug users themselves, their families, and the wider caring community to act as intervention workforce to give life-saving interim emergency care. Summary of Scope: This article explores 5 areas (many illustrations UK-based where the author works): firstly, the need for strong science; secondly, our improved understanding of opioid overdose and deaths; thirdly, the search for greater impact from our policies and interventions; fourthly, developing better forms of naloxone; and fifthly, examining the challenges still to be addressed.

KEY MESSAGES

"Take-home naloxone" is an exemplar of harm reduction with potential global impact - drug policy and practice for the public good. However, "having the potential" is not good enough - there needs to be actual implementation. This will be easier once the component parts of "take-home naloxone" are improved (better naloxone products, better training aids, revised legislation, and explicit funding support). Many improvements are already possible, but we hesitate about implementation. It is our responsibility to drive progress faster. With "take-home naloxone," we can be proud of what we have achieved, but we must also be humble about how much more we still need to do.

Outcomes of Ottawa, Canada's Managed Opioid Program (MOP) where supervised injectable hydromorphone was paired with assisted housing

BACKGROUND

The Ottawa Inner City Health's Managed Opioid Program is the first, to our knowledge, to pair injectable opioid agonist hydromorphone treatment with assisted housing for people experiencing homelessness with severe opioid use disorder (OUD) and injection drug use. We aimed to describe this program and evaluate retention, health, and social wellbeing outcomes.

METHODS

We retrospectively assessed the first cohort of clients enrolled in the Managed Opioid Program between August 2017-2018. The primary outcome was retention at 12 months. Secondary outcomes included injectable and oral opioid dose titration, non-prescribed opioid use, overdoses, connection with behavioural health services, and social well-being. Descriptive statistics were used to summarize baseline demographics and secondary outcomes. Actuarial survival analysis was used to assess retention among participants.

RESULTS

The study sample included 26 participants: median age was 36 years, 14 were female, 22 were White, eight had alcohol use disorders, 25 had stimulant use disorders, and all had a history of concurrent psychiatric illness. Retention at 12 months was 77% (95% CI 62-95). Throughout the first-year participants' opioid treatment doses increased. The median daily dose of injectable hydromorphone was 36 mg [17-54 mg] and 156 mg [108-188 mg] at enrollment and one year respectively. The median daily dose of oral opioid treatment was 120-milligram morphine equivalents [83-180 mg morphine equivalents] and 330-milligram morphine equivalents [285-428 mg morphine equivalents] at enrollment and one year respectively. Over half had no overdoses and there were no deaths among participants who remained enrolled. At one year, 45% stopped non-prescribed opioid use, 96% connected to behavioral health services, 73% reconnected with estranged families, and 31% started work or vocational programs.

CONCLUSION

Individuals with severe OUD engaged in injectable hydromorphone treatment and housing showed high retention in care and substantive improvements in patient-centered health and social well-being outcomes.

Reducing opioid use in post-operative otolaryngology patients: A quality improvement project

PURPOSE

In opioid-naive patients, many low-risk surgical procedures are associated with an increased risk of chronic opioid use. The goal of this quality improvement project was to reduce the amount of opioid prescriptions after commonly performed surgeries in otolaryngology.

MATERIALS AND METHODS

Pre-intervention opioid prescribing state was measured using anonymous provider and patient surveys, as well as pharmacy provider prescription data. Next, this information was used to develop an opioid prescription protocol that both standardized opioid prescribing practices and encouraged multimodal analgesia following routine surgery. Finally, post-intervention data were gathered and compared to pre-intervention data to assess changes in prescribing patterns.

RESULTS

By patient survey, the worst pain and average pain after surgery (scale of 1-10) were unchanged after the intervention (5.1 to 4.8, p = 0.52; 4.1 to 3.6, p = 0.35, respectively). Post-intervention, 41% of patients reported receiving no opiates, whereas pre-intervention 100% of patients surveyed received opiates. The amount of ibuprofen and acetaminophen prescribed post-intervention increased 113% and 71%, respectively. By survey, the average number of opioid doses decreased from 24.0 ± 7.0 to 18.4 ± 6.6 (p = 0.018).

CONCLUSIONS

The implementation of a standardized physician opioid prescription protocol did not affect patient pain perceptions, resulted in an increase in multimodal analgesia prescription, and increased provider awareness of opioid over prescription.

Use of average volume-assured pressure support as a therapeutic option in patients with central sleep apnea syndrome

PURPOSE

Central sleep apnea (CSA) syndrome commonly occurs with other medical conditions such as congestive heart failure, opiate use, and brainstem disorders. Various treatment modalities have been used with varied effectiveness in an attempt to improve ventilation and reduce the apnea-hypopnea index (AHI) in patients with CSA. This study evaluated whether or not a bilevel positive airway pressure mode of noninvasive ventilation, average volume-assured pressure support (AVAPS) is effective in treating CSA.

METHODS

This was a retrospective review of patients with CSA who underwent AVAPS titration studies at our institution. We included patients with CSA with apnea-hypopnea index (events/hour) (AHI) ≥ 15, and examined the effectiveness of AVAPS in reducing AHI, improving oxygenation parameters, and improving sleep architecture.

RESULTS

There were 12 patients, with mean age 62.8 ± 11.5 years, body mass index (BMI) 33.5 ± 4.7 kg/m², 8 men, and Epworth Sleepiness Scale 9.3 ± 4.9. Five patients had CSA attributed to opiate use, 4 patients had CSA with Cheyne-Stokes respiration, and 3 patients had primary CSA. The only significant change from baseline PSG was AHI reduction with AVAPS: 63.3 ± 19.1 to 30.5 ± 30.3 (p < 0.003). In 5 patients (42%), AHI was reduced to < 15 with AVAPS use. Improvement in AHI was not related to gender, BMI, opiate use, or age. Defining response to therapy as AHI reduced to < 15, we found that lack of hypertension was the only significant predictor of response (p = 0.045). No significant changes in sleep architecture between the two studies were found.

CONCLUSION

AVAPS is an effective mode of treating CSA in a significant proportion of patients. More studies are needed to confirm these findings and determine what factors are associated with response to therapy.

Timing of Oversedation Events Following Opiate Administration in Hospitalized Patients

BACKGROUND

Unintended overdoses of opiate medications are potentially lethal events. Monitoring patients for oversedation is fundamental to ensuring safe use of opiates, and the timing of this evaluation is guided by the onset of action, time to max effect and duration of action of the opiate. The study's aim was to describe the timing of oversedation in relation to the predicted duration of action of the administered opiate.

METHODS

This study was conducted as a retrospective review of all opiate-related oversedation events during a 2-year period involving patients admitted to an urban teaching hospital.

RESULTS

Of the 53 opiate-related oversedation events evaluated, 47% occurred after the predicted maximal duration of action of the administered opiate.

CONCLUSION

Opiate-induced oversedation routinely occurs after predicted based upon duration of action. The study findings have profound implications upon nursing practice regarding duration of time required to monitor for opiate-induced oversedation.

Medication adherence, utilization of healthcare services, and mortality of patients with epilepsy on opiate replacement therapy: A retrospective cohort study

INTRODUCTION

Substance misuse is not uncommonly recognized in people with epilepsy (PWE). Mortality is significantly greater in those with comorbid substance misuse, but it remains unclear whether epilepsy care and management contribute to this. This cohort study aimed to compare the rates of mortality in PWE receiving opiate replacement therapy (ORT) and PWE alone, as well as evaluate their medication adherence, levels of engagement with epilepsy services as currently delivered, and utilization of unscheduled hospital care.

MATERIAL AND METHODS

A 5-year historical cohort for PWE was identified and manually validated using electronic patient records registered with NHS Tayside. Overall incidence rates for mortality and contact with emergency health care services were calculated for PWE receiving ORT and PWE alone. Engagement with outpatient epilepsy services was also noted. Adherence to antiepileptic drugs (AEDs) was expressed in terms of medication possession ratio (MPR).

RESULTS

Of the 1297 PWE attending a tertiary care epilepsy service, 68 (5.3%) PWE were receiving ORT. The mortality rate was significantly greater in PWE on ORT in comparison to PWE only (7.4% vs 1.7 %; P < 0.05; relative risk of death: 4.34, 95% CI 1.19-15.7), as well as the incidence of emergency healthcare services contact being higher (24.5% vs 17.7%; P < 0.05; incidence rate ratio: 1.39, 95% CI: 1.12-1.71). Poor adherence to AEDs was also more common in PWE on ORT (28.4% vs 23.5%; P = 0.02), as well as failure to engage with elective outpatient services (8.4% vs 3.0%; P < 0.05; rate ratio 2.77, 95% CI: 1.86-4.1).

CONCLUSION

People with epilepsy on ORT are less likely to engage with elective epilepsy services as currently delivered or take AEDs as prescribed despite most of these patients having daily attendance at a community pharmacist. This may contribute to the significantly increased rates of mortality and unscheduled hospital care. Clinicians and policymakers should consider service redesign to meet the demands of this high-risk population in an attempt to reduce mortality and morbidity.

Opioid use during pregnancy can impair maternal behavior and the Maternal Brain Network: A literature review

Opioid Use Disorder (OUD) is a global epidemic also affecting women of reproductive age. A standard form of pharmacological treatment for OUD is Opioid Maintenance Therapy (OMT) and buprenorphine has emerged as the preferred treatment for pregnant women with OUD relative to methadone. However, the consequences of BUP exposure on the developing Maternal Brain Network and mother-infant dyad are not well understood. The maternal-infant bond is dependent on the Maternal Brain Network, which is responsible for the dynamic transition from a "nulliparous brain" to a "maternal brain". The Maternal Brain Network consists of regions implicated in maternal care (e.g., medial preoptic area, nucleus accumbens, ventral pallidum, ventral tegmentum area) and maternal defense (e.g., periaqueductal gray). The endogenous opioid system modulates many of the neurochemical changes in these areas during the transition to motherhood. Thus, it is not surprising that exogenous opioid exposure during pregnancy can be disruptive to the Maternal Brain Network. Though less drastic than misused opioids, OMTs may not be without risk of disrupting the neural and molecular structures of the Maternal Brain Network. This review describes the Maternal Brain Network as a framework for understanding how pharmacological differences in exogenous opioid exposure can disrupt the onset and maintenance of the maternal brain and summarizes opioid and OMT (in particular buprenorphine) use in the context of pregnancy and maternal behavior. This review also highlights future directions for evaluating exogenous opioid effects on the Maternal Brain Network in the hopes of raising awareness for the impact of the opioid crisis not only on exposed infants, but also on mothers and subsequent mother-infant bonds.

Validation of the Opioid Overdose Knowledge (OOKS) and Attitudes (OOAS) Scales in French, Spanish, and German Languages, among a Sample of Opioid Users

INTRODUCTION

Improving the knowledge and attitudes of people facing an opioid overdose is one of the key prevention measures for reducing overdose occurrence and severity. In this respect, the Opioid Overdose Knowledge Scale (OOKS) and Opioid Overdose Attitudes Scale (OOAS) have been developed and validated in English to assess and improve knowledge and attitudes of opioid users and their families and care providers, in case of an overdose. Here, the OOKS and OOAS scales have been translated into French, Spanish, and German, and the different versions of the 2 scales have been assessed regarding their psychometric properties.

METHODS

The translation procedure of the scales was based on the international recommendations, including a back translation by a native English speaker. Subsequently, 80 (Spain: 29, France: 27, Germany: 24) former or current heroin users, aged from 20 to 61 years (M = 39.4 ± 9.23), completed the OOKS and OOAS versions of their native language, in test-retest, without specific between-assessment training. Internal consistency was assessed using Cronbach's α, while test-retest reliability was assessed using intraclass correlation coefficient (ICC). The correlation between the OOKS and OOAS scores of a same language was assessed using Spearman's (ρ) coefficient.

RESULTS

Internal consistency of the OOKS was found to be good to very good, with Cronbach's α ranging from 0.62 to 0.87. Test-retest reliability was also very good, with ICCs ranging from 0.71 to 0.82. However, results were less reliable for the OOAS, as internal consistency was questionable to acceptable, with Cronbach's α ranging from 0.12 to 0.63, while test-retest ICCs were very good for the French (0.91) and Spanish (0.99) versions and barely acceptable for the German version (0.41). No significant correlation was found between the OOKS and OOAS scores, irrespective of the version concerned.

CONCLUSION

While satisfactory results were found for the 3 versions of the OOKS, results on the OOAS were relatively inconsistent, suggesting a possible gap between knowledge and attitudes on overdose among opioid users.

Restless Legs Syndrome: Contemporary Diagnosis and Treatment

Restless legs syndrome (RLS) is characterized by an uncomfortable urge to move the legs while at rest, relief upon movement or getting up to walk, and worsened symptom severity at night. RLS may be primary (idiopathic) or secondary to pregnancy or a variety of systemic disorders, especially iron deficiency, and chronic renal insufficiency. Genetic predisposition with a family history is common. The pathogenesis of RLS remains unclear but is likely to involve central nervous system dopaminergic dysfunction, as well as other, undefined contributing mechanisms. Evaluation begins with a thorough history and examination, and iron measures, including ferritin and transferrin saturation, should be checked at presentation and with worsened symptoms, especially when augmentation develops. Augmentation is characterized by more intense symptom severity, earlier symptom occurrence, and often, symptom spread from the legs to the arms or other body regions. Some people with RLS have adequate symptom control with non-pharmacological measures such as massage or temperate baths. First-line management options include iron-replacement therapy in those with evidence for reduced body-iron stores or, alternatively, with prescribed gabapentin or pregabalin, and dopamine agonists such as pramipexole, ropinirole, and rotigotine. Second-line therapies include intravenous iron infusion in those who are intolerant of oral iron and/or those having augmentation with intense, severe RLS symptoms, and opioids including tramadol, oxycodone, and methadone. RLS significantly impacts patients' quality of life and remains a therapeutic area sorely in need of innovation and a further pipeline of new, biologically informed therapies.

Incidental biliary dilation in the era of the opiate epidemic: High prevalence of biliary dilation in opiate users evaluated in the Emergency Department

BACKGROUND

Biliary dilation is frequently related to obstruction; however, non-obstructive factors such as age and previous cholecystectomy have also been reported. In the past two decades there has been a dramatic increase in opiate use/dependence and utilization of cross-sectional abdominal imaging, with increased detection of biliary dilation, particularly in patients who use opiates.

AIM

To evaluate associations between opiate use, age, cholecystectomy status, ethnicity, gender, and body mass index utilizing our institution’s integrated informatics platform.

METHODS

One thousand six hundred and eighty-five patients (20% sample) presenting to our Emergency Department for all causes over a 5-year period (2011-2016) who had undergone cross-sectional abdominal imaging and had normal total bilirubin were included and analyzed.

RESULTS

Common bile duct (CBD) diameter was significantly higher in opiate users compared to non-opiate users (8.67 mm vs 7.24 mm, P < 0.001) and in patients with a history of cholecystectomy compared to those with an intact gallbladder (8.98 vs 6.72, P < 0.001). For patients with an intact gallbladder who did not use opiates (n = 432), increasing age did not predict CBD diameter (r² = 0.159, P = 0.873). Height weakly predicted CBD diameter (r² = 0.561, P = 0.018), but weight, body mass index, ethnicity and gender did not.

CONCLUSION

Opiate use and a history of cholecystectomy are associated with CBD dilation in the absence of an obstructive process. Age alone is not associated with increased CBD diameter. These findings suggest that factors such as opiate use and history of cholecystectomy may underlie the previously-reported association of advancing age with increased CBD diameter. Further prospective study is warranted.

Fifty Years of Research and One Conclusion: Opium Causes Cancer

In September 2020, the International Agency for Research on Cancer (IARC) announced that opium consumption causes cancer in humans - a conclusion drawn after reviewing data from five decades of research. Given the widespread use of opium and its derivatives by millions of people across the world, the classification of opium consumption as a "Group 1" carcinogen has important public health ramifications. In this mini-review, we offer a short history of opium use in humans and briefly review the body of research that led to the classification of opium consumption as carcinogenic. We also discuss possible mechanisms of opium's carcinogenicity and potential avenues for future research.

Mortality Risk in Chronic Kidney Disease Patients Transitioning to Dialysis: Impact of Opiate and Non-Opiate Use

BACKGROUND

Population-based studies show there is a high prevalence of chronic kidney disease (CKD) patients suffering from chronic pain. While opiates are frequently prescribed in non-dialysis-dependent CKD (NDD-CKD) patients, there may be toxic accumulation of metabolites, particularly among those progressing to end-stage renal disease (ESRD). We examined the association of opiate versus other analgesic use during the pre-ESRD period with post-ESRD mortality among NDD-CKD patients transitioning to dialysis.

METHODS

We examined a national cohort of US Veterans with NDD-CKD who transitioned to dialysis over 2007-14. Among patients who received ≥1 prescription(s) in the Veterans Affairs (VA) Healthcare System within 1 year of transitioning to dialysis, we examined associations of pre-ESRD analgesic status, defined as opiate, gabapentin/pregabalin, other non-opiate analgesic, versus no analgesic use, with post-ESRD mortality using multivariable Cox models.

RESULTS

Among 57,764 patients who met eligibility criteria, pre-ESRD opiate and gabapentin/pregabalin use were each associated with higher post-ESRD mortality (ref: no analgesic use), whereas non-opiate analgesic use was not associated with higher mortality in expanded case-mix analyses: HRs (95% CIs) 1.07 (1.05-1.10), 1.07 (1.01-1.13), and 1.00 (0.94-1.06), respectively. In secondary analyses, increasing frequency of opiate prescriptions exceeding 1 opiate prescription in the 1-year pre-ESRD period was associated with incrementally higher post-ESRD mortality (ref: no analgesic use).

CONCLUSIONS

In NDD-CKD patients transitioning to dialysis, pre-ESRD opiate and gabapentin/pregabalin use were associated with higher post-ESRD mortality, whereas non-opiate analgesic use was not associated with death. There was a graded association between increasing frequency of pre-ESRD opiate use and incrementally higher mortality.

Opioid Analgesics Do Not Improve Abdominal Pain or Quality of Life in Crohn's Disease

BACKGROUND

Abdominal pain and opioid analgesic use are common in Crohn's disease (CD).

AIMS

We sought to identify factors associated with abdominal pain in CD and evaluate the impact of opioid analgesics on pain and quality-of-life scores in this setting.

METHODS

We performed a longitudinal cohort study using a prospective, consented IBD natural history registry from a single academic center between 2009 and 2013. Consecutive CD patients were followed for at least 1 year after an index visit. Data were abstracted regarding pain experience (from validated surveys), inflammatory activity (using endoscopic/histologic findings), laboratory studies, coexistent psychiatric disorders, medical therapy, opioid analgesic, and tobacco use.

RESULTS

Of 542 CD patients (56.6% women), 232 (42.8%) described abdominal pain. Individuals with pain were more likely to undergo surgery and were more frequently prescribed analgesics and/or antidepressants/anxiolytics. Elevated ESR (OR 1.79; 95%CI 1.11-2.87), coexistent anxiety/depression (OR 1.87; 95%CI 1.13-3.09), smoking (OR 2.08; 95%CI 1.27-3.40), and opioid use (OR 2.46; 95%CI 1.33-4.57) were independently associated with abdominal pain. Eighty patients (14.8%) were prescribed opioids, while 31 began taking them at or after the index visit. Patients started on opioids demonstrated no improvement in abdominal pain or quality-of-life scores on follow-up compared to patients not taking opioids.

CONCLUSIONS

Abdominal pain is common in CD and is associated with significant opioid analgesic utilization and increased incidence of anxiety/depression, smoking, and elevated inflammatory markers. Importantly, opioid use in CD was not associated with improvement in pain or quality-of-life scores. These findings reinforce the limitations of currently available analgesics in IBD and support exploration of alternative therapies.

Trajectories of initiation for the heroin-based drug whoonga - qualitative evidence from South Africa

BACKGROUND

Whoonga is a smoked heroin-based street drug that first emerged in South Africa a decade ago. While previous scientific reports suggest that use is growing and youth are particularly vulnerable, trajectories of initiation are not well characterized.

METHODS

In 2015, 30 men undergoing residential addiction treatment for this smoked heroin drug in KwaZulu-Natal, South Africa participated in semi-structured interviews about their experiences using the drug. Interview data were coded using qualitative content analysis.

RESULTS

Participant trajectories to initiating smoked heroin were "vertical" in the context of marijuana use or "horizontal" in the context of other hard drug use. Participants reporting vertical trajectories began smoking heroin as youth at school or in other settings where people were smoking marijuana. Several participants with horizontal trajectories started smoking heroin to address symptoms of other drug or alcohol addiction. Social influences on initiation emerged as an overarching theme. Members of participants' social networks who were smoking or distributing heroin figured prominently in initiation narratives. Surprisingly, references to injection drug use were absent from initiation narratives. Participants reported people who smoke heroin differ from those who inject heroin by race.

CONCLUSION

Consistent with theories implicating social and structural influences on substance use initiation, people who started smoking heroin had social contacts who smoked heroin and frequented places where substance use was common. Smoked heroin initiation for several participants with horizontal trajectories may have been averted if they accessed evidence-based treatments for stimulant or alcohol use disorders. With increasing reports of heroin use across Africa, a coordinated approach to address this growing epidemic is needed. However, because smoked heroin and injection heroin use occur in distinct risk environments, interventions tailored to people who use smoked heroin will be needed to prevent smoked heroin use, prevent transition to injection use, and mitigate other social harms.

Preoperative Chronic Opiate Use and Patient Reported Outcomes Following Adult Spinal Reconstructive Surgery

BACKGROUND

Preoperative chronic narcotic use has been linked to poor outcomes after surgery for degenerative spinal disorders in the form of lower health-related quality of life scores, higher revision rates, increased infections, lower likelihood of return to work, and higher 90-day readmission rates. This study evaluated the impact of preoperative chronic narcotic use on patient reported outcome measures following adult spinal reconstructive surgery.

METHODS

Patients who underwent adult spinal reconstructive surgery over 2 years at our institution were identified from a prospectively maintained spine registry. These patients were grouped into chronic opiate users as defined by a 6-month duration of use with a minimum morphine equivalent dose of 30 mg/day. Patient reported outcome measures were collected prospectively.

RESULTS

Of 140 patients included for analysis, 30 (21.4%) patients were categorized as chronic opiate users. No differences were identified in mean preoperative patient reported outcome measures, including Oswestry Disability Index, health state, visual analog scale, and EQ-5D indices. At both 6 weeks and 6 months postoperatively, patients in the opiate group demonstrated significantly worse mean visual analog scale back pain scores relative to the nonopiate group. At 6 months postoperatively and at the last known clinical follow-up, Oswestry Disability Index scores were higher in the opiate group.

CONCLUSIONS

Chronic opiate use before adult spinal reconstructive surgery was associated with worse pain and disability following intervention. Further work is needed to understand the role of opiate weaning as part of a larger prehabilitation strategy for adult spinal reconstructive surgery.

Persistent effects of the orexin-1 receptor antagonist SB-334867 on motivation for the fast acting opioid remifentanil

The orexin (hypocretin) system is multifaceted, and regulates sleep-wake cycles, nociception, endocrine function and reward-seeking behavior. We have established an important role for this system in motivation for drugs of abuse. The orexin-1 receptor (Ox1R) antagonist SB334867 (SB) reduces seeking of drug reward under conditions of high motivation. There is some evidence that the effects of systemic SB on reward seeking persist beyond the pharmacological availability of the drug, however the time course of these effects is not well characterized, nor is it known whether similar persistent effects are observed following intraparenchymal injections. Here, we used a behavioral economics paradigm, which allows for repeated testing of drug motivation across consecutive days, to examine the persistent effects of acute systemic and local treatment with SB on motivation for the short-acting μ-opioid receptor agonistremifentanil. Systemic injections of SB immediately prior to behavioral testing reduced motivation for remifentanil; this effect was sustained on a subsequent test at 24 h, but not on a third test at 48 h. When injected into ventral pallidum (VP) the effects of SB were more persistent, with reduced motivation observed for up to 48 h. We next made SB injections into VP 24 h prior to behavioral testing; this produced effects that persisted for at least 72 h post-treatment. Cued reinstatement of extinguished remifentanil seeking was also attenuated by pretreatment with SB 24 h earlier. These data indicate that the effects of SB on opioid seeking behavior persist beyond the bioavailability of the compound. These observations have important ramifications for the future clinical use of orexin receptor antagonists for the treatment of addiction.

Association between Adult Attention Deficit/Hyperactivity Disorder and Intravenous Misuse of Opioid and Benzodiazepine in Patients under Opioid Maintenance Treatment: A Cross-Sectional Multicentre Study

BACKGROUND

Intravenous misuse and attention-deficit/hyperactivity disorder (ADHD) are common in patients under opioid maintenance treatment (OMT), who often misuse benzodiazepine (BZD).

OBJECTIVES

To explore the rate of adult ADHD among patients under OMT in Italy and whether screening positive for adult ADHD is associated with OMT and BZD misuse and emergency room (ER) admission because of misuse.

METHODS

We recruited 1,649 patients from 27 addiction units (AUs) in Italy and collected data on the self-reported rate of OMT intravenous misuse (prevalence, repeated misuse, main reason, temporal pattern in relation to AU access, experience), concurrent intravenous and intranasal BZD misuse (prevalence, type of misused BZD), ADHD and ER admissions because of misuse complications.

RESULTS

Screening positive for adult ADHD was found in 11.2% patients (ADHD+), with a significant gender difference (women: 15.3%, men: 10.3%). OMT misuse was reported by 24.4 and 18.5% patients during lifetime and in the previous 6 months respectively. BZD misuse was reported by 20.0 and 8.6% patients for intravenous and intranasal route respectively. Misuse was significantly more common in ADHD+ (OMT 27.4-33.1%, BZD 14.5-31.5%) than ADHD- group (OMT 17.4-23.3%, BZD 7.9-18.3%). The multivariate logistic regression model showed positive screening for ADHD to be significantly associated with intravenous OMT misuse in the previous 6 months, and intravenous/intranasal BZD misuse, independently of age, gender and route of previous heroin administration.

CONCLUSIONS

Screening positive for adult ADHD was associated with OMT and BZD misuse. AU physicians and medical personnel should focus on OMT patient's features that are associated with a higher likelihood of misuse, in particular ADHD.

μ-Opioid receptors in primary sensory neurons are involved in supraspinal opioid analgesia

Both inhibiting ascending nociceptive transmission and activating descending inhibition are involved in the opioid analgesic effect. The spinal dorsal horn is a critical site for modulating nociceptive transmission by descending pathways elicited by opioids in the brain. μ-Opioid receptors (MORs, encoded by Oprm1) are highly expressed in primary sensory neurons and their central terminals in the spinal cord. In the present study, we tested the hypothesis that MORs expressed in primary sensory neurons contribute to the descending inhibition and supraspinal analgesic effect induced by centrally administered opioids. We generated Oprm1 conditional knockout (Oprm1-cKO) mice by crossing Advillin^Cre/+ mice with Oprm1^flox/flox mice. Immunocytochemical labeling in Oprm1-cKO mice showed that MORs are completely ablated from primary sensory neurons and are profoundly reduced in the superficial spinal dorsal horn. Intracerebroventricular injection of morphine or fentanyl produced a potent analgesic effect in wild-type mice, but such an effect was significantly attenuated in Oprm1-cKO mice. Furthermore, the analgesic effect produced by morphine or fentanyl microinjected into the periaqueductal gray was significantly greater in wild-type mice than in Oprm1-cKO mice. Blocking MORs at the spinal cord level diminished the analgesic effect of morphine and fentanyl microinjected into the periaqueductal gray in both groups of mice. Our findings indicate that MORs expressed at primary afferent terminals in the spinal cord contribute to the supraspinal opioid analgesic effect. These presynaptic MORs in the spinal cord may serve as an interface between ascending inhibition and descending modulation that are involved in opioid analgesia.

Pharmacological treatments of augmentation in restless legs syndrome patients

Augmentation, a treatment-induced paradoxical worsening of the symptoms of restless legs syndrome (RLS) that is caused by long-term dopaminergic therapy, in particular with higher doses, remains the major challenge of RLS treatment. The mainstay of treatment continues to be preventing augmentation, either by starting RLS therapy with alternative drugs or by sensitizing physicians about the absolute necessity of respecting approved dosages of dopaminergic drugs when treating RLS and never exceeding the maximum recommended dosages. In the case of a positive diagnosis of augmentation, treatment consists of reducing or eliminating dopaminergic therapy, ensuring that serum ferritin is clearly higher than the level assumed to be necessary from a hematological point of view and/or switching treatment to alternative drugs such as α2δ ligands, opiates, or to combination therapy.

Factors Associated With Opiate Use Among Psychiatric Inpatients: A Population-Based Study of Hospital Admissions in Ontario, Canada

Background:

Use of opiates, including synthetic opioids, is associated with a number of negative consequences, including increased risk of opioid use disorders and other mental health conditions. However, studies are limited in examining patterns of opiate use among persons in inpatient psychiatry, particularly those that consider the relationship between pain and opiate use.

Objective:

This study examined the prevalence in the prior 12 months to admission and patterns of opiate use and pain in a population-based study of persons admitted to inpatient psychiatry in Ontario, Canada.

Methods:

We conducted retrospective cross-sectional study of 165 434 persons admitted to inpatient psychiatry between January 1, 2006 and December 31, 2017. Using data from the Resident Assessment Instrument for Mental Health, we examined prevalence and factors associated with opiate use in the prior 12 months by a number of patient characteristics, including demographics, mental and physical health status, concurrent substance use, pain severity and frequency, and health region of residence.

Results:

The prevalence of opiate use within 12 months of admission was 7.5%, between 17% and 22% among those experiencing daily pain, and 27% among persons with a primary substance use disorder. Multivariable analyses revealed strong associations among demographic and clinical variables with opiate use (c = 0.91), including being of younger age, use of other substances, greater frequency and severity of pain, and health region of residence.

Conclusion:

The strong relationship between pain and opiate use in this population, and the regional variation in this pattern, supports the need for integrated care for mental illness and substance use, and therapeutic approaches to pain management that reduce risks of problems associated with substance use for persons with mental health conditions.

Developmental opioid exposures: Neurobiological underpinnings, behavioral impacts, and policy implications

The devastating impact of opioid abuse and dependence on the individual, family, and society are well known but extremely difficult to combat. During pregnancy, opioid drugs and withdrawal also affect fetal brain development and newborn neural functions, in addition to maternal effects. Neonatal Abstinence Syndrome/Neonatal Opioid Withdrawal Syndrome (NAS/NOWS) rates have drastically increased in the US in the past decade. Solutions to this complex problem must be multi-faceted, which would be greatly enhanced by a translational, multidisciplinary understanding. Therefore, this mini-review incorporates biomedical, clinical, and policy aspects of opioid use during pregnancy. We review the known roles for endogenous opioids in mediating circuit formation and function in the developing brain, discuss how exogenous opioid drug use and addiction impact these processes in animal models and humans, and discuss the implications of these data on public policy. We suggest that some current policy initiatives produce unintended harm on both mothers and their children and delineate recommendations for how legislation could better contribute to addiction recovery and increase neural resilience in affected children.

Impact statement

Opioid abuse is a critical epidemic affecting individuals, families, and communities. This mini-review summarizes current literature on the impact of opioid drugs—including prescription pain relievers and illicit opioids—on neurobiological and neurobehavioral development. Using concepts related to the medical model of addiction as a brain disease, we review the public policy implications of these data and identify needs for future investigations.

Increasing heroin, cocaine, and buprenorphine arrests reported to the Maine Diversion Alert Program

BACKGROUND

The opioid overdose crisis is especially pronounced in Maine. The Diversion Alert Program (DAP) was developed to combat illicit drug use and prescription drug diversion by facilitating communication between law enforcement and health care providers with the goal of limiting drug-related harms and criminal behaviors. Our objectives in this report were to analyze 2014-2017 DAP for: (1) trends in drug arrests and, (2) differences in arrests by offense, demographics (sex and age) and by region.

METHODS

Drug arrests (N=8193, 31.3% female, age=33.1±9.9) reported to the DAP were examined by year, demographics, and location.

RESULTS

The most common substances of the 10,064 unique charges reported were heroin (N=2203, 21.9%), crack/cocaine (N=945, 16.8%), buprenorphine (N=812, 8.1%), and oxycodone (N=747, 7.4%). While the overall number of arrests reported to the DAP declined in 2017, the proportion of arrests involving opioids (heroin, buprenorphine, or fentanyl) and stimulants (cocaine/crack cocaine, or methamphetamine), increased (p<.05). Women had significantly increased involvement in arrests involving sedatives and miscellaneous pharmaceuticals (e.g. gabapentin) while men had an elevation in stimulant arrests. Heroin accounted for a lower percentage of arrests among individuals age >60 (6.6%) relative to young-adults (18-29, 22.3%, p<.0001). Older-adults had significantly more arrests than younger-adults for oxycodone, hydrocodone, and marijuana.

CONCLUSION

Heroin had the most arrests from 2014 to 2017. Buprenorphine, fentanyl and crack/cocaine arrests increased appreciably suggesting that improved treatment is needed to prevent further nonmedical use and overdoses. The Diversion Alert Program provided a unique data source for research, a harm-reduction tool for health care providers, and an informational resource for law enforcement.

Pain therapy - Are there new options on the horizon?

This article reviews the role of analgesic drugs with a particular emphasis on opioids. Opioids are the oldest and most potent drugs for the treatment of severe pain, but they are burdened by detrimental side effects such as respiratory depression, addiction, sedation, nausea, and constipation. Their clinical application is undisputed in acute (e.g., perioperative) and cancer pain, but their long-term use in chronic pain has met increasing scrutiny and has contributed to the current opioid crisis. We discuss epidemiological data, pharmacological principles, clinical applications, and research strategies aiming at novel opioids with reduced side effects.

Profiling of morphine and codeine in urine after the ingestion of curry containing poppy seed as an evidence for opiates defence in Malaysia

Consumption of curry containing poppy seeds has raised an issue concerning the opiate content in the urine that might exceed the cut-off value (300ng/mL). The main objective of this study was to examine the morphine and codeine contents in the urine of the consumers after partaking poppy seed-enriched curry in. The volunteers were asked to partake: (a) a single meal and their urines were collected within 24h, or (b) Two meals a day for three consecutive days and their urines were collected within 72h. Two different dosages were also tested in this study: (a) low dosage: 1g/100ml curry (containing 138μg of morphine and 66μg of codeine) and (b) high dosage: 5g/100ml curry (containing 690μg of morphine and 330μg of codeine). The subjects were randomised into the groups using the method of stratified randomization with age and gender groups as covariates. A total of 6 subjects was allocated for each group and placebos were used as control. Results showed that all subjects who consumed low dosage of poppy seeds either in single meal or multiple meals experiment were found negative. However, 1 out of 6high dosage subjects was confirmed positive at a period of 3-6h after the consumption of curry in the single meal study. This outlier maybe due to the lack of water consumption after consuming the curry, thus the low volume of urine was collected and the opiate was concentrated in the urine. On the other hand, 5 out of 6high dosage subjects in the multiple meals experiment were found positive. Majority of these subjects were found positive on the second and third day of the experiment after the second curry meal was consumed. The outlier (negative) in this group might be due to the high consumption of water throughout the experiment and the subject's urine volumes and frequency of urine collection were much higher compared to other subjects. From the result of this study, it can be concluded that partaking high dosages of poppy seed in curry could give a positive response (>300ng/ml+uncertainty of measurement) in the urine, and the water consumption after partaking curry has significant influence for the opiate contents in the urine.

Social modulation of drug use and drug addiction

This review aims to demonstrate how social science and behavioral neurosciences have highlighted the influence of social interactions on drug use in animal models. In neurosciences, the effect of global social context that are distal from drug use has been widely studied. For human and other social animals such as monkeys and rodents, positive social interactions are rewarding, can overcome drug reward and, in all, protect from drug use. In contrast, as other types of stress, negative social experiences facilitate the development and maintenance of drug abuse. However, interest recently emerged in the effect of so-called "proximal" social factors, that is, social interactions during drug-taking. These recent studies have characterized the role of the drug considered, the sharing of drug experience and the familiarity of the peer which interaction are made with. We also examine the few studies regarding the sensorial mediator of social behaviors and critically review the neural mediation of social factors on drug use. However, despite considerable characterization of the factors modulating distal influences, the mechanisms for proximal influences on drug use remain largely unknown. This article is part of the Special Issue entitled 'The neuropharmacology of social behavior: from bench to bedside'.

Determination of circuit-specific morphological adaptations in ventral tegmental area dopamine neurons by chronic morphine

Chronic opiate exposure induces neuroadaptations in the mesocorticolimbic system including ventral tegmental area (VTA) dopamine (DA) neurons, whose soma size is decreased following opiate exposure. Yet it is now well documented that VTA DA neurons are heterogeneous, with notable differences between VTA DA neurons based on their projection target. Therefore, we sought to determine whether chronic morphine induced similar changes in the morphology of VTA DA neurons that project to the nucleus accumbens (NAc) and prefrontal cortex (PFC). We utilized Cre-dependent retrograde viral vectors in DA Cre driver lines to label VTA DA neurons that projected to NAc and PFC and assessed neuronal soma size. Consistent with previous data, the soma size of VTA DA neurons that projected to the NAc medial shell was decreased following morphine exposure. However, soma size of VTA DA neurons that projected to the NAc core was unaltered by morphine. Interestingly, morphology of PFC-projecting VTA DA neurons was also altered by morphine, but in this case soma size was increased compared to sham controls. Differences in basal soma size were also noted, suggesting stable differences in projection-specific morphology in addition to drug-induced changes. Together, these data suggest morphine-induced changes in VTA DA morphology occur within distinct VTA DA populations and that study of opiate-induced structural plasticity of individual VTA DA subcircuits may be critical for understanding addiction-related behavior.

Opioid distribution trends (2006-2017) in the US Territories

Background

The US mainland is experiencing an epidemic of opioid overdoses. Unfortunately, the US Territories (Guam, Puerto Rico, and the Virgin Islands) have often been overlooked in opioid pharmacoepidemiology research. This study examined common prescription opioids over the last decade.

Methods

The United States Drug Enforcement Administration’s Automation of Reports and Consolidated Orders System (ARCOS) was used to report on ten medical opioids: buprenorphine, codeine, fentanyl, hydrocodone, hydromorphone, meperidine, methadone, morphine, oxycodone, and oxymorphone, by weight from 2006 to 2017. Florida and Hawaii were selected as comparison areas.

Results

Puerto Rico had the greatest Territorial oral morphine mg equivalent (MME) per capita (421.5) which was significantly higher (p < .005) than the Virgin Islands (139.2) and Guam (118.9) but significantly lower than that of Hawaii (794.6) or Florida (1,509.8). Methadone was the largest opioid by MMEs in 2017 in most municipalities, accounting for 41.1% of the total in the Virgin Islands, 37.9% in Florida, 36.6% in Hawaii but 80.8% in Puerto Rico. Puerto Rico and Florida showed pronounced differences in the distribution patterns by pharmacies, hospitals, and narcotic treatment programs for opioids.

Conclusions

Continued monitoring of the US Territories is needed to provide a balance between appropriate access to these important agents for cancer related and acute pain while also minimizing diversion and avoiding the opioid epidemic which has adversely impacted the US mainland.

The effects of licit and illicit recreational drugs on prospective memory: a meta-analytic review

RATIONALE

There are no recent reports summarising the magnitude of prospective memory (PM) impairments in recreational drug users.

OBJECTIVE

We performed a meta-analysis of studies (with a parallel group design) examining PM performance in users of common recreational drugs (including alcohol and tobacco) who were not intoxicated during testing. Studies were also evaluated for the presence of methodological bias.

METHODS

Twenty-seven studies were included in the meta-analysis following literature searches of MEDLINE, EMBASE and PsycINFO. Effect sizes (standardised mean difference; SMD) were calculated separately for the effects of alcohol, cannabis, ecstasy, methamphetamine and tobacco use. The influences of drug use and study characteristics on effect sizes were explored using meta-regressions. Sources of study bias were also assessed.

RESULTS

Heavy drinkers and regular drug users tended to perform worse than controls on event and time-based PM tasks. Effect sizes (standardised mean differences; SMDs) for event-based PM impairment across the different drug-using groups/heavy drinkers ranged between - 1.10 and - 0.49, with no 95% CI crossing 0.00. SMDs for time-based PM ranged between - 0.98 and - 0.70. Except for the CIs associated with the ES for smokers' time-based PM performance, no CIs crossed 0.00.

CONCLUSIONS

Although all drug-using groups showed moderate-large impairments in event and time-based PM, effect sizes had low precision and moderate-high levels of heterogeneity. In addition, several methodological and reporting issues were identified in the majority of studies. As such, considerable uncertainty remains regarding the role of confounds and the magnitude of PM impairments in non-intoxicated recreational drug users.

The DARK Side of Total Synthesis: Strategies and Tactics in Psychoactive Drug Production

Humankind has used and abused psychoactive drugs for millennia. Formally, a psychoactive drug is any agent that alters cognition and mood. The term "psychotropic drug" is neutral and describes the entire class of substrates, licit and illicit, of interest to governmental drug policy. While these drugs are prescribed for issues ranging from pain management to anxiety, they are also used recreationally. In fact, the current opioid epidemic is the deadliest drug crisis in American history. While the topic is highly politicized with racial, gender, and socioeconomic elements, there is no denying the toll drug mis- and overuse is taking on this country. Overdose, fueled by opioids, is the leading cause of death for Americans under 50 years of age, killing ca. 64,000 people in 2016. From a chemistry standpoint, the question is in what ways, if any, did organic chemists contribute to this problem? In this targeted review, we provide brief historical accounts of the main classes of psychoactive drugs and discuss several foundational total syntheses that ultimately provide the groundwork for producing these molecules in academic, industrial, and clandestine settings.

The effectiveness of attentional bias modification for substance use disorder symptoms in adults: a systematic review

BACKGROUND

Attentional bias modification (ABM) interventions have been developed to address addiction by reducing attentional bias for substance-related cues. This study provides a systematic review of the effectiveness of ABM interventions in decreasing symptoms of addictive behaviour, taking baseline levels of attentional bias and changes in attentional bias into account.

METHODS

We included randomised and non-randomised studies that investigated the effectiveness of ABM interventions in heavy-using adults and treatment-seeking individuals with symptoms of substance use disorder to manipulate attentional bias and to reduce substance use-related symptoms. We searched for relevant English peer-reviewed articles without any restriction for the year of publication using PsycINFO, PubMed, and ISI Web in August 2016. Study quality was assessed regarding reporting, external validity, internal validity, and power of the study.

RESULTS

Eighteen studies were included: nine studies reported on ABM intervention effects in alcohol use, six studies on nicotine use, and three studies on opiate use. The included studies differed with regard to type of ABM intervention (modified dot probe task n = 14; Alcohol Attention Control Training Programme n = 4), outcome measures, amount and length of provided sessions, and context (clinic versus laboratory versus home environment). The study quality mostly ranged from low average to high average (one study scored below the quality cut-off). Ten studies reported significant changes of symptoms of addictive behaviour, whereas eight studies found no effect of ABM interventions on symptoms. However, when restricted to multi-session ABM intervention studies, eight out of ten studies found effects on symptoms of addiction. Surprisingly, these effects on symptoms of addictive behaviour showed no straightforward relationship with baseline attentional bias and its change from baseline to post-test.

CONCLUSIONS

Despite a number of negative findings and the diversity of studies, multi-session ABM interventions, especially in the case of alcohol and when the Alcohol Attention Control Training Programme was used, appear to have positive effects on symptoms of addictive behaviour. However, more rigorous well-powered future research in clinical samples is needed before firm conclusions regarding the effectiveness of ABM interventions can be drawn.

SYSTEMATIC REVIEW REGISTRATION

Registration number PROSPERO: CRD42016046823.

Social Influences in Animal Models of Opiate Addiction

Opiate addiction has reached an epidemic prevalence in recent years, yet social influences on the use and abuse of opiates has been widely understudied. In particular, the neurobiological substrates of opiate addiction and their modulation by social influences are largely unknown, perhaps due to the lack of widespread incorporation of social variables into animal models of opiate addiction. As reviewed here, animal models such as oral and intravenous drug self-administration, conditioned place preference, behavioral sensitization, and the effects of various stressors, have been useful in identifying some of the neurochemical circuitry that mediate social influences on opiate addiction. However, it is clear from our review that newer paradigms that incorporate various social elements are greatly needed to provide more translational insights into the neurobiological basis of opiate addiction. These elements include social and environmental enrichment, presence of conspecifics, and procedures that require subjects to exert effort to engage in prosocial behavior. A wider implementation of social variables into animal models of opiate addiction will help inform neurobehavioral strategies to increase the efficacy of treatment.

Comparison between buprenorphine provider availability and opioid deaths among US counties

BACKGROUND

Buprenorphine is an effective medication for the treatment of opioid addiction, but current barriers to buprenorphine access limit treatment availability for many patients. We identify and characterize regions within the United States (US) with poor buprenorphine access relative to the observed burden of overdose deaths.

METHODS

This cross sectional study includes US county-level data on the number of available buprenorphine providers (Substance Abuse and Mental Health Services Administration Buprenorphine Treatment Practitioner Locator) and the number of opioid-related overdose deaths between 2013 and 2015 (Centers for Disease Control and Prevention WONDER Database). Counties with fewer than 10 deaths during this time period were excluded to maintain patient privacy. Population-adjusted county death rates and provider availability were compared to identify locations with high disease burdens and limited buprenorphine access. The presence of significant clustering across the dataset was evaluated using Global Moran's I and zones of significant spatial clusters and anomalies were identified using Local Indicator of Spatial Autocorrelation.

RESULTS

County data were available for 846 counties from 49 states and the District of Columbia, comprising 83% of the US population. The median number of opioid overdose deaths per county was 20.0 deaths per 100,000 residents (interquartile range 13.4-29.9, range 2.9 to 108.8). The number of buprenorphine providers per 100,000 county residents ranged from 0 to 45, with a median of 5.9 (interquartile range 3.2 to 9.5). Global Moran's I analysis yielded significant clustering in the distribution of both providers and deaths, with notable significant clusters of higher than average providers and deaths in the Northeast, and scattered mismatched regions of lower-than-average providers and higher-than-average deaths across the Southern, Midwestern, and Western US. Graphical analysis of buprenorphine provider availability and overdose burden reveals limited treatment access relative to overdose deaths throughout much of the Midwestern and Southern US.

CONCLUSIONS

Substantial county-level imbalances between the availability of buprenorphine providers and the burden of opioid overdose deaths are present within the US.

Decision-making, somatic markers and emotion processing in opiate users

RATIONALE

Opiate use is associated with deficits in decision-making. A possible explanation for these deficits is provided by the somatic marker hypothesis, which suggests that substance users may experience abnormal emotional responses during decision-making involving reward and punishment. This in turn may interfere with the brief physiological arousal, i.e. somatic markers that normally occur in anticipation of risky decisions. To date, the applicability of the somatic marker hypothesis to explain decision-making deficits has not been investigated in opiate users.

OBJECTIVES

This study assessed whether decision-making deficits in opiate users were related to abnormal emotional responses and reduced somatic markers.

METHODS

Opiate users enrolled in an opiate substitute treatment program (n = 28) and healthy controls (n = 32) completed the Iowa Gambling Task (IGT) while their skin conductance responses (SCRs) were recorded. Participants' emotional responses to emotion-eliciting videos were also recorded using SCRs and subjective ratings.

RESULTS

Opiate users displayed poorer decision-making on the IGT than did controls. However, there were no differences between the groups in SCRs; both groups displayed stronger SCRs following punishment than following reward, and both groups displayed stronger anticipatory SCRs prior to disadvantageous decisions than advantageous decisions. There were no group differences in objective or subjective measures of emotional responses to the videos.

CONCLUSIONS

The results suggest that deficits in emotional responsiveness are not apparent in opiate users who are receiving pharmacological treatment. Thus, the somatic marker hypothesis does not provide a good explanation for the decision-making deficits in this group.