Gabapentin misuse, abuse and diversion: a systematic review

Key articles and guidelines for the emergency medicine clinical pharmacist: 2011-2018 update

PURPOSE

To summarize recently published research reports and practice guidelines on emergency medicine (EM)-related pharmacotherapy.

SUMMARY

Our author group was composed of 14 EM pharmacists, who used a systematic process to determine main sections and topics for the update as well as pertinent literature for inclusion. Main sections and topics were determined using a modified Delphi method, author and peer reviewer groups were formed, and articles were selected based on a comprehensive literature review and several criteria for each author-reviewer pair. These criteria included the document "Oxford Centre for Evidence-based Medicine - Levels of Evidence (March 2009)" but also clinical implications, interest to reader, and belief that a publication was a "key article" for the practicing EM pharmacist. A total of 105 articles published from January 2011 through July 2018 were objectively selected for inclusion in this review. This was not intended as a complete representation of all available pertinent literature. The reviewed publications address the management of a wide variety of disease states and topic areas that are commonly found in the emergency department: analgesia and sedation, anticoagulation, cardiovascular emergencies, emergency preparedness, endocrine emergencies, infectious diseases, neurology, pharmacy services and patient safety, respiratory care, shock, substance abuse, toxicology, and trauma.

CONCLUSION

There are many important recent additions to the EM-related pharmacotherapy literature. As is evident with the surge of new studies, guidelines, and reviews in recent years, it is vital for the EM pharmacist to continue to stay current with advancing practice changes.

Icilio Guareschi and his amazing "1897 reaction"

Organic chemistry honors Icilio Guareschi (1847-1918) with three eponymic reactions, the best known ones being the Guareschi synthesis of pyridones and the Guareschi-Lustgarten reaction. A third Guareschi reaction, the so-called "Guareschi 1897 reaction", is one of the most unusual reactions in organic chemistry, involving the radical-mediated paradoxical aerobic generation of hydrocarbons in near-neutral water solution. A discussion of the mechanism of this amazing reaction, the only metal-free process that generates hydrocarbons, and the implications of the approach in biology and geosciences mirrors the multifaceted scientific personality of the discoverer. Thus, Guareschi's eclectic range of activities spans a surprising variety of topics, overcoming the boundaries of the traditional partition of chemistry into organic, inorganic, and analytical branches and systematically crosses the divide between pure and applied science as well as between the history of chemistry and the personal contributions to its development.

Gabapentin reduces postoperative pain and opioid consumption in patients who underwent lumbar laminectomy

BACKGROUND

Postoperative pain management solely with opioids elevates the risk of opioid-related adverse events during hospitalization and after discharge from the hospital. Clinical trials have demonstrated gabapentinoids as viable adjunctive treatments for spinal surgeries. However, only a few practice-based studies have examined the efficacy of gabapentin as an opioid-sparing agent for patients undergoing lumbar laminectomy in rural hospital settings.

OBJECTIVE

To determine the effects of gabapentin on opioid consumption and pain perception in patients who underwent lumbar laminectomy at a rural community hospital.

METHODS

Data were collected by retrospective chart reviews of 99 patients who underwent lumbar laminectomy at Yavapai Regional Medical Center from January 1, 2017, to July 1, 2019. The patients were stratified into 2 groups: those who were taking gabapentin as outpatients before surgery and were continued on the same dose postoperatively (n = 50, gabapentin group) and those who were not taking gabapentin preoperatively or postoperatively (n = 49, usual-treatment group). The primary end points were opioid consumption in morphine milligram equivalents (MME) and pain for 24 hours postsurgery.

RESULTS

Outcomes from the mixed-model analysis of variance showed significant main effects of group and time for opioid consumption in MME (F_1,97 = 4.3, P < 0.05 and F_3,291 = 133.9, P < 0.001, respectively) and numerical pain scale scores (F_1,99 = 4.0, P < 0.05 and F_3,241 = 21.4, P < 0.001, respectively) and group-time interaction for opioid consumption in MME (F_3,291 = 2.6, P = 0.05). Post hoc analyses showed that opioid consumption in MME was significantly lower in the gabapentin group than in the usual-treatment group for the first 6 hours postoperatively. The pain scores were significantly lower in the gabapentin group than in the usual-treatment group across all time periods.

CONCLUSION

Patients on gabapentin showed reductions in pain perception and postoperative opioid consumption. The results extend the findings from randomized trials to a real-world clinical setting. These data support using gabapentin in conjunction with opioids for pain management of patients undergoing lumbar laminectomy.

Risk of infection within 4 weeks of corticosteroid injection (CSI) in the management of chronic pain during a pandemic: a cohort study in 216 patients

OBJECTIVES

Targeted corticosteroid injections (CSI) are one of the treatments that can provide pain relief and thereby, enhance quality of life in patients with chronic pain. Corticosteroids (CS) are known to impair immune response. The objective was to evaluate the risk of developing post-procedural infection within 4 weeks of receiving depot CSI for chronic pain as part of on going quality improvement project. We hypothesised that interventional treatment with depot steroids will not cause a significant increase in clinical infection in the first 4 weeks.

METHODS

Telephone follow-up was performed as a part of prospective longitudinal audit in a cohort of patients who received interventional treatment for chronic pain at a multidisciplinary pain medicine centre based at a university teaching hospital. Patients who received interventional treatment in the management of chronic pain under a single physician between October 2019 and December 2020 were followed up over telephone as part of on going longitudinal audits. Data was collected on any infection within 4 and 12 weeks of receiving the intervention. Outcomes collected included type of intervention, dose of depot steroids and pain relief obtained at 12 weeks following intervention.

RESULTS

Over a 15 month period, 261 patients received pain interventions with depot CS. There was no loss to follow-up. Nine patients reported an infection within 4 weeks of receiving depot steroids (9/261, 3.4%). None of the patients tested positive for Covid-19. Eight patients (8/261, 3%) reported an infection between 5 and 12 weeks following the corticosteroid intervention. Although none of the patients tested positive for Covid-19, two patients presented with clinical and radiological features suggestive of Covid-19. Durable analgesia was reported by 51% (133/261) and clinically significant analgesia by 30% (78/261) at 12 weeks following the intervention. Failure rate was 19% (50/261).

CONCLUSIONS

Pain medicine interventions with depot steroids do not appear to overtly increase the risk for Covid-19 infection in the midst of a pandemic.

Patterns of Neonatal Co-Exposure to Gabapentin and Commonly Abused Drugs Observed in Umbilical Cord Tissue

Gabapentin was thought to have low abuse potential, but it is increasingly being abused by people with substance use disorder in an attempt to potentiate the euphoric effects from opioids and other CNS depressants. Additionally, infants co-exposed to gabapentin and opioids during pregnancy tend to exhibit prolonged and more severe neonatal abstinence syndrome. In this study, we describe positivity rates among commonly abused drugs and rates of co-medication with gabapentin in a large dataset of umbilical cord tissue specimens (n = 25,422) submitted for routine newborn drug testing at a national clinical reference laboratory (ARUP Laboratories, Salt Lake City, UT, USA). Detection of prenatal drug exposure in umbilical cord tissue specimens was accomplished using a semi-quantitative liquid chromatography-tandem mass spectrometry assay designed to detect 47 specific drugs and drug metabolites including opioids, stimulants, sedative-hypnotics and hallucinogens. A positive result for at least one of the measured drugs or drug metabolites was reported in 7,054 (28%) of the umbilical cord tissues analyzed. Gabapentin had a positivity rate of ~2% with 562 positive results. Of the 562 gabapentin-positive samples, 395 (70%) also had a positive result for at least one other drug or drug metabolite, with the highest co-positivity rate observed for norbuprenorphine (32%, n = 182) followed by amphetamine (15%, n = 84), buprenorphine (13%, n = 74), methamphetamine (12%, n = 68), morphine (11%, n = 64), fentanyl (10%, n = 54) and naloxone (10%, n = 54). Notably, the concentration of gabapentin in gabapentin-positive umbilical cord specimens was higher in buprenorphine-containing specimens as compared to specimens containing other opioids, stimulants or benzodiazepines. Identification of neonatal co-exposure to gabapentin and opioids, particularly buprenorphine, may guide clinicians in rapid initiation of monitoring and intervention for neonatal abstinence syndrome.

Pregabalin and gabapentin in non-opioid poisoning deaths

Post-mortem findings of gabapentinoids have often been connected to drug abuse and especially opioid use. We aimed to investigate whether gabapentinoids have been implicated in the cause of death without the presence of opioids. In a three-year study period from 2016 to 2018, a total of 907 Finnish post-mortem cases positive for pregabalin or gabapentin were found. In nearly half of the pregabalin cases and in a third of the gabapentin cases, the blood concentration was above the typical therapeutic range of the drug. Of the cases in which pregabalin was detected, in 35% the drug was implicated in a fatal poisoning with or without other drugs or alcohol. For gabapentin, the percentage was 22%. In most of the fatal gabapentinoid poisonings, opioids or other central nervous system depressants were additionally detected in relevant concentrations. There were eight non-opioid gabapentinoid poisonings, in which no relevant other drugs were detected. Many of these cases were unintentional poisonings with a relatively high gabapentinoid concentration in the blood. In all but one, the manner of death was accidental, or the intent was undetermined. This study confirmed the previous findings that gabapentinoids are mostly implicated in fatal poisoning together with opioids. Half of the non-opioid cases were related to drug abuse but in the other half the death was presumably caused by overuse of a prescribed drug or suicide. While the use of gabapentinoids is a well-known problem among people who use drugs, it is important to note other groups of users who may be at risk of overdose by gabapentinoids.

Perioperative Opioid Administration

Opioids form an important component of general anesthesia and perioperative analgesia. Discharge opioid prescriptions are identified as a contributor for persistent opioid use and diversion. In parallel, there is increased enthusiasm to advocate opioid-free strategies, which include a combination of known analgesics and adjuvants, many of which are in the form of continuous infusions. This article critically reviews perioperative opioid use, especially in view of opioid-sparing versus opioid-free strategies. The data indicate that opioid-free strategies, however noble in their cause, do not fully acknowledge the limitations and gaps within the existing evidence and clinical practice considerations. Moreover, they do not allow analgesic titration based on patient needs; are unclear about optimal components and their role in different surgical settings and perioperative phases; and do not serve to decrease the risk of persistent opioid use, thereby distracting us from optimizing pain and minimizing realistic long-term harms.

Identifying insomnia-related chemicals through integrative analysis of genome-wide association studies and chemical-genes interaction information

STUDY OBJECTIVES

Insomnia is a common sleep disorder and constitutes a major issue in modern society. We provide new clues for revealing the association between environmental chemicals and insomnia.

METHODS

Three genome-wide association studies (GWAS) summary datasets of insomnia (n = 113,006, n = 1,331,010, and n = 453,379, respectively) were driven from the UK Biobank, 23andMe, and deCODE. The chemical-gene interaction dataset was downloaded from the Comparative Toxicogenomics Database. First, we conducted a meta-analysis of the three datasets of insomnia using the METAL software. Using the result of meta-analysis, transcriptome-wide association studies were performed to calculate the expression association testing statistics of insomnia. Then chemical-related gene set enrichment analysis (GSEA) was used to explore the association between chemicals and insomnia.

RESULTS

For GWAS meta-analysis dataset of insomnia, we identified 42 chemicals associated with insomnia in brain tissue (p < 0.05) by GSEA. We detected five important chemicals such as pinosylvin (p = 0.0128), bromobenzene (p = 0.0134), clonidine (p = 0.0372), gabapentin (p = 0.0372), and melatonin (p = 0.0404) which are directly associated with insomnia.

CONCLUSION

Our study results provide new clues for revealing the roles of environmental chemicals in the development of insomnia.

Dual-trajectories of opioid and gabapentinoid use and risk of subsequent drug overdose among Medicare beneficiaries in the United States: a retrospective cohort study

BACKGROUND AND AIMS

Little is known about opioid and gabapentinoid (OPI-GABA) use duration and dose patterns' associations with adverse outcome risks. We examined associations between OPI-GABA dose and duration trajectories and subsequent drug overdose.

DESIGN

Retrospective cohort study.

SETTING

US Medicare.

PARTICIPANTS

Using a 5% sample (2011-16), we identified 71 005 fee-for-service Medicare beneficiaries with fibromyalgia, low back pain, neuropathy and/or osteoarthritis initiating OPIs and/or GABAs [mean age ± standard deviation (SD) = 65.5 ± 14.5 years, female = 68.1%, white = 76.8%].

MEASUREMENTS

Group-based multi-trajectory models identified distinct OPI-GABA use patterns during the year of OPI and/or GABA initiation, based on weekly average standardized daily dose (i.e. OPIs = morphine milligram equivalent, GABAs = minimum effective daily dose). We estimated models with three to 12 trajectories and selected the best model based on Bayesian information criterion (BIC) and Nagin's criteria. We estimated risk of time to first drug overdose diagnosis within 12 months following the index year, adjusting for socio-demographic and health factors using inverse probability of treatment weighted multivariable Cox proportional hazards models.

FINDINGS

We identified 10 distinct trajectories (BIC = -1 176 954; OPI-only = 3, GABA-only = 3, OPI-GABA = 4). Compared with OPI-only early discontinuers (40.6% of the cohort), 1-year drug overdose risk varied by trajectory group: consistent low-dose OPI-only users [16.6%; hazard ratio (HR) = 1.47, 95% confidence interval (CI) = 1.19-1.82], consistent high-dose OPI-only users (1.8%; HR = 4.57, 95% CI = 2.99-6.98), GABA-only early discontinuers (12.5%; HR = 1.39, 95% CI = 1.09-1.77), consistent low-dose GABA-only users (11.0%; HR = 1.44, 95% CI = 1.12-1.85), consistent high-dose GABA-only users (3.1%; HR = 1.43, 95% CI = 0.94-2.17), early discontinuation of OPIs and consistent low-dose GABA users (6.9%; HR = 1.24, 95% CI = 0.90-1.69), consistent low-dose OPI-GABA users (3.4%; HR = 2.49, 95% CI = 1.76-3.52), consistent low-dose OPI and high-dose GABA users (3.2%; HR = 2.46, 95% CI = 1.71-3.53) and consistent high-dose OPI and moderate-dose GABA users (0.9%; HR = 7.22, 95% CI = 4.46-11.69).

CONCLUSIONS

Risk of drug overdose varied substantially among US Medicare beneficiaries on different use trajectories of opioids and gabapentinoids. High-dose opioid-only users and all consistent opioid and gabapentinoid users (regardless of doses) had more than double the risk of subsequent drug overdose compared with opioid-only early discontinuers.

Gabapentin dependence and withdrawal requiring an 18-month taper in a patient with alcohol use disorder: a case report

Gabapentin has been widely used to manage post-herpetic neuralgia, peripheral neuropathy, seizure disorders, alcohol use disorder (AUD), alcohol withdrawal, and insomnia. Although usually well tolerated, gabapentin has been reported to cause severe physiologic dependence and withdrawal. Tapering gabapentin in this context poses a significant clinical challenge, with little published information to date on meeting this challenge. This case highlights the need for patient-centered slow tapers in patients with severe gabapentin dependence and withdrawal. We present a 32-year-old female effectively treated for AUD with 1,200 mg daily dose of gabapentin, who developed gabapentin dependence and severe withdrawal. Recognizing her intolerance to gabapentin withdrawal after a brief accidental pause of medication, a taper plan was initiated using the framework of the BRAVO Protocol. On average, she reduced daily gabapentin dose by 100 mg per month until she reached 300 mg. The taper then slowed to 20-30 mg dose decrements per month. For the last 100 mg, she tapered down at 5 mg decrements every one to two weeks to 60 mg, at which point she discontinued gabapentin. The entire taper process took eighteen months. The BRAVO protocol outlines a safe and compassionate strategy. Originally developed for opioids and adapted to benzodiazepines, the use of the Bravo Protocol provides a framework for a gabapentin taper. For patients in whom gabapentin treatment leads to severe dependence and withdrawal, the BRAVO Protocol provides a practical, patient-centered framework for tapering.

Assessment of gabapentin misuse using prescription drug monitoring program data

BACKGROUND

Gabapentin is an anticonvulsant medication with potential misuse reported in case reports and population studies, highlighting the need to reexamine its abuse liability. The purpose of this study was to describe gabapentin dispensing patterns and assess potential misuse. Methods: We used data from Ohio's Prescription Drug Monitoring Program (PDMP) from December 1, 2016 to March 31, 2017 and restricted the population to adults who filled at least one gabapentin prescription (N = 379,372). Gabapentin dispensing patterns are described and multiple strategies were used to assess potential misuse, including Lorenz-1 curve analysis. Supratherapeutic dosing, number of prescribers and number of pharmacies used were compared for individuals who were co-dispensed medications for opioid use disorder (MOUD) and those who were not. Results: More than one million gabapentin prescriptions were dispensed during the 4-month period, with a mean dose of 1103.8 mg. While few individuals received supratherapeutic dosing, exceptionally high doses were observed. Half of the individuals (50.9%) were co-dispensed gabapentin and opioids. The Lorenz-1 value for gabapentin (5.5%) did not exceed the threshold for misuse potential. Individuals co-dispensed MOUD were more likely to have supratherapeutic dosing; however, they had a lower Lorenz-1 value compared to individuals not co-dispensed MOUD. Conclusions: Among Ohio residents dispensed gabapentin, there was no evidence of misuse using PDMP data based on the Lorenz-1 value, yet supratherapeutic dosing of gabapentin was observed and was associated with OUD. New strategies may be needed to identify the non-medical use of gabapentin.

[Weighing the benefits and harms of psychotropic and analgesic substances - A perspective of German addiction medicine experts]

BACKGROUND

In Europe, there have been several addiction-expert rankings of harms related to the use of psychotropic substances in the last 15 years. Among them, only one expert ranking took into account the potential benefits of these drugs. Non-Opioidergic Analgesics (NOAs), such as gabapentinoids and NSAIDs, which have been increasingly the subject of abuse / misuse reports, have not been considered in such expert rankings. Likewise, there is currently no multi-substance comparison as to whether the valuation rank of the harmfulness of an illegal drug may change along with an imagined change in legal status in Germany.

OBJECTIVES AND METHODS

Using a questionnaire, 101 experienced addiction physicians (first cohort) evaluated 33 psychoactive substances including analgesics with regard to their health and social harms as well as potential usefulness for the consumer and their environment / society ('others'). In addition, this cohort investigated whether the harmfulness assessment of an illegal substance changes if it would be legalized. In order to obtain the average overall harmfulness (overall risk) of a substance, the percentage contribution of each dimension to the overall harmfulness was determined in a second survey (second cohort, 36 experienced addiction medicine experts). Finally, the average benefit and overall risk ratings of each substance were related to each other.

RESULTS

Prescription psychoactive substances such as analgesics, NOAs (including gabapentinoids) and opioidergic maintenance medications to treat opiate dependence were judged to have a favorable benefit-harm profile. Cannabis and ketamine were placed in the midfield of both, the harm and benefit rankings. Together with most illicit narcotic drugs, alcohol and nicotine, have been ranked among the most harmful and least useful substances, whereby alcohol was judged on average to be more harmful but also more useful than nicotine. In the event of potential legalization, the overall harm of the traditional illegal drugs methamphetamine, heroin, cocaine and cannabis was estimated to be reduced. This was mainly due to a more favorable valuation of the harm to others under these virtual conditions.

CONCLUSION

Prescription substances including opioidergic and non-opioidergic analgesics as well as opioid maintenance therapy medications (methadone and buprenorphine) were assigned a favorable benefit-harm profile. Alcohol, nicotine and traditional illicit drugs (with the exception of cannabis and ketamine) were determined to have an unfavorable profile. The overall harm of traditional illicit drugs was assessed to decrease along with legalization, mainly by decreasing the harm to others in this virtual event.

Prevalence of and Factors Associated with Gabapentinoid Use and Misuse Among Texas Medicaid Recipients

BACKGROUND AND OBJECTIVES

Gabapentin and pregabalin have been considered relatively safe opioid-sparing adjuncts for pain management. However, rising prescribing trends, presence of gabapentinoids in opioid-related overdoses, and the growing body of evidence regarding gabapentinoid misuse and abuse, have caused gabapentinoids to emerge as a drug class of public health concern. This study aimed to assess the prevalence of, and factors associated with gabapentinoid use and misuse.

METHODS

This retrospective study of Texas Medicaid data from 1/1/2012 to 30/8/2016 included patients aged 18-63 years at index date, with ≥ 1 gabapentinoid prescription, and continuously enrolled 6 months pre-index and 12 months post-index. Gabapentinoid misuse was defined as ≥ 3 claims exceeding daily doses of 3600 mg for gabapentin and 600 mg for pregabalin. Age, gender, concurrent opioid use, neuropathic pain diagnoses and gabapentinoid type were independent variables. Descriptive and inferential statistics were used.

RESULTS

Of included subjects (N = 39,000), 0.2% (N = 81) met study criteria for gabapentinoid misuse. Overall, the majority (76.4%) of gabapentinoid users were aged 41-63 years with a mean ± SD age of 48.2 ± 10.7 years. Those patients meeting the study criteria for gabapentinoid misuse were significantly younger (45.1 ± 11.0 vs 48.2 ± 10.7, p = 0.0084). Majority of the study sample was female (68.1%). However, a significantly higher proportion of males met the study criteria for gabapentinoid misuse compared to females (0.3% vs 0.2%, p = 0.0079). Approximately one-half (51.9%) of the study sample had neuropathic pain, and gabapentinoid misuse was significantly higher in neuropathic pain patients compared to those without neuropathic pain (0.3% vs 0.1%, p = 0.0078). Over three-quarters (77.4%) of patients were using gabapentin; however, gabapentinoid misuse was significantly higher among pregabalin users (0.4% vs 0.2%, p = 0.0003). Approximately 20% (17.3%) of gabapentinoid users had ≥ 90 days of concurrent opioid use. However, there was no significant difference in gabapentinoid misuse among patients with concurrent opioid use compared to patients without (0.3% vs 0.2%, p = 0.1440). Factors significantly associated with misuse included: male sex (odds ratio [OR] 0.486; 95% confidence interval [CI] 0.313-0.756; p = 0.0013); neuropathic pain (OR 2.065; 95% CI 1.289-3.308; p = 0.0026); and pregabalin versus gabapentin use (OR 2.337, 95% CI 1.492-3.661; p = 0.0002). Concurrent opioid use was not significantly associated with gabapentinoid misuse (OR 1.542, 95% CI 0.920-2.586; p = 0.1006).

CONCLUSION

Prevalence of gabapentinoid misuse was low (0.2%) among Texas Medicaid recipients. Younger age, male gender, neuropathic pain diagnosis and pregabalin use were significantly associated with higher levels of gabapentinoid misuse.

Association Between Dual Trajectories of Opioid and Gabapentinoid Use and Healthcare Expenditures Among US Medicare Beneficiaries

OBJECTIVES

Little is known about relationships between opioid- and gabapentinoid-use patterns and healthcare expenditures that may be affected by pain management and risk of adverse outcomes. This study examined the association between patients' opioid and gabapentinoid prescription filling/refilling trajectories and direct medical expenditures in US Medicare.

METHODS

This cross-sectional study included a 5% national sample (2011-2016) of fee-for-service beneficiaries with fibromyalgia, low back pain, neuropathy, or osteoarthritis newly initiating opioids or gabapentinoids. Using group-based multitrajectory modeling, this study identified patients' distinct opioid and gabapentinoid (OPI-GABA) dose and duration patterns, based on standardized daily doses, within a year of initiating opioids and/or gabapentinoids. Concurrent direct medical expenditures within the same year were estimated using inverse probability of treatment weighted multivariable generalized linear regression, adjusting for sociodemographic and health status factors.

RESULTS

Among 67 827 eligible beneficiaries (mean age ± SD = 63.6 ± 14.8 years, female = 65.8%, white = 77.1%), 11 distinct trajectories were identified (3 opioid-only, 4 gabapentinoid-only, and 4 concurrent OPI-GABA trajectories). Compared with opioid-only early discontinuers ($13 830, 95% confidence interval = $13 643-14 019), gabapentinoid-only early discontinuers and consistent low-dose and moderate-dose gabapentinoid-only users were associated with 11% to 23% lower health expenditures (adjusted mean expenditure = $10 607-$11 713). Consistent low-dose opioid-only users, consistent high-dose opioid-only users, consistent low-dose OPI-GABA users, consistent low-dose opioid and high-dose gabapentinoid users, and consistent high-dose opioid and moderate-dose gabapentinoid users were associated with 14% to 106% higher healthcare expenditures (adjusted mean expenditure = $15 721-$28 464).

CONCLUSIONS

Dose and duration patterns of concurrent OPI-GABA varied substantially among fee-for-service Medicare beneficiaries. Consistent opioid-only users and all concurrent OPI-GABA users were associated with higher healthcare expenditures compared to opioid-only discontinuers.

Trends in unintentional polysubstance overdose deaths and individual and community correlates of polysubstance overdose, North Carolina, 2009-2018

BACKGROUND

Polysubstance involvement is increasing among fatal drug overdoses. However, little is known about the epidemiology of polysubstance drug overdoses. This paper describes emerging trends in unintentional polysubstance overdose deaths in North Carolina (NC) and examines associations with individual and community factors.

METHODS

Using 2009-2018 NC death certificate data, we identified unintentional drug overdose deaths and commonly involved substances (opioids, stimulants, benzodiazepines, alcohol, and antiepileptics). We examined polysubstance combinations, comparing opioid and non-opioid involved deaths. We examined individual level correlates from death certificate data and community level correlates from the American Community Survey and Robert Wood Johnson Foundation County Health Rankings to quantify associations.

RESULTS

From 2009-2018, 53 % of opioid and 19 % of non-opioid overdose deaths involved multiple substances. During this period, polysubstance overdose death increased dramatically, from 2.9 to 12.1 per 100,000 persons, with the greatest increases among drug combinations involving stimulants. The most common polysubstance combinations were: opioids and stimulants (12.1 % of overdose deaths); opioids and benzodiazepines (9.0 %); opioids and alcohol (5.1 %); opioids, stimulants, and benzodiazepines (3.1 %); and opioids, benzodiazepines, and antiepileptics (2.2 %). Compared to overdoses involving opioids alone, overdoses involving combinations of opioids, stimulants, and benzodiazepines involved younger individuals (53.7 % in 15-34 years of age vs. 40.7 %). Men comprised two-thirds of overdoses involving opioids alone, however, overdoses involving opioids, benzodiazepines, and antiepileptics were predominantly among women (60.6 %).

CONCLUSIONS

Polysubstance involvement has increased among overdose deaths in NC. These findings can be used to inform public health interventions addressing polysubstance deaths and associated individual and community level factors.

Neurotoxic effects of pregabalin dependence on the brain frontal cortex in adult male albino rats

Pregabalin (PGB) is an analog of the inhibitory neurotransmitter gamma-aminobutyric acid. The currently available evidence favors the misuse and abuse potential of PGB. However, its neurotoxicity remains unclear. Therefore, this study assessed the toxic effects of chronic pregabalin dependence as well as withdrawal on the cortical neurons of the frontal lobe. This study included eighty adult male albino rats which were divided into three groups. Group I (Control) included 40 rats and was further subdivided into two equal subgroups (IA and IB) as negative and positive controls. Group II (PGB-dependent) included 20 rats which received PGB starting with the therapeutic dose (300 mg/day), then the doses were gradually increased until they reached the dependent dose (3400 mg/day) by the end of the first month. Further, the dependent dose was given daily for another 2 months. Group III (PGB withdrawal) included 20 rats which received PGB as described in group II. After that, administration of PGB was stopped and the rats were kept for another one month. By the end of the experiment, all animals were sacrificed by cervical decapitation. The specimens were taken from the frontal cortex for histologic and immunohistochemical staining as well as morphometric analysis. Sections of the frontal cortex of group II showed changes in the form of disturbed architectural pattern of cortical layers, apoptotic cells, weak immunoexpression of Bcl-2 and VEGF as well as moderate-strong immunoexpression of iNOS and nestin. These expressions were significantly different from the control groups, but they were non-significant in comparison with group III. These findings indicate that chronic PGB dependence induces neurotoxic effects mainly in the form of neuronal apoptosis, gliosis, and oxidative stress injury of the frontal cortex. The PGB- induced neurotoxic effects persisted after withdrawal. The influence of these neurotoxic effects and their relevance to the cognitive or neurologic disorders in PGB-dependent individuals warrants further research. Furthermore, it is recommended to quantify the behavioral changes related to PGB dependence as well as withdrawal in future studies.

Gabapentin-Induced Myokymia: A Case Report

BACKGROUND

Gabapentin is a commonly used medication for neuropathic pain and epilepsy that is prescribed by a wide range of medical specialties. Adverse effects including asterixis and myoclonus have been described in patients with chronic kidney disease, but myokymia has not been previously reported.

CASE PRESENTATION

A 69-year-old man with a history of traumatic brain injury, peripheral neuropathy, amnesia, and posttraumatic stress disorder presented to the hospital after multiple falls attributed to acute onset muscle spasms. He reported taking a total daily dose of 9600 mg of gabapentin, as prescribed. Physical examination demonstrated stimulus-sensitive myoclonus, painful muscle spasms in all extremities, and myokymia in his bilateral calves. Diffuse action tremors, as well as tongue tremors, were also observed.Initial workup, including basic laboratory investigations, brain imaging, and electroencephalogram, was unrevealing. Gabapentin toxicity was suspected, and a gabapentin holiday was initiated with the improvement of myokymia by hospital day 3. The patient was found to have a high gabapentin level (25.8 μg/mL; reference range, 2.0-20.0 μg/mL) measured the morning after hospital presentation. After restarting on a lower dose of gabapentin with multimodal pain control, the patient continued to improve with diminution of his myoclonus, tremor, and gait instability.

CONCLUSIONS

Myokymia is a newly described motor symptom associated with gabapentin toxicity. The mechanism of gabapentin-associated myokymia is currently unknown. A brief medication holiday resulted in the resolution of motor symptoms without significant withdrawal symptoms. Knowledge of this newly reported adverse manifestation can aid physicians in the diagnosis of gabapentin toxicity and prompt treatment, as gabapentin levels are not widely or immediately available.

Pregabalin for neuropathic pain in primary care settings: recommendations for dosing and titration

Pregabalin is one of the first-line treatments approved for the management of neuropathic pain (NeP). While many patients benefit from treatment with pregabalin, they are often treated with suboptimal doses, possibly due to unfamiliarity around prescribing the drug and/or side effects that can occur with up-titration. This narrative review discusses key aspects of initiating, titrating, and managing patients prescribed pregabalin therapy, and addresses concerns around driving and the potential for abuse, as well as when to seek specialist opinion. To ensure that patients derive maximum therapeutic benefit from the drug, we suggest a 'low and slow' dosing approach to limit common side effects and optimize tolerability alongside patients' expectations. When requiring titration to higher doses, we recommend initiating 'asymmetric dosing,' with the larger dose in the evening. Fully engaging patients in order for them to understand the expected timeline for efficacy and side effects (including their resolution), can also help determine the optimal titration tempo for each individual patient. The 'low and slow' approach also recognizes that patients with NeP are heterogeneous in terms of their optimal therapeutic dose of pregabalin. Hence, it is recommended that general practitioners closely monitor patients and up-titrate according to pain relief and side effects to limit suboptimal dosing or premature discontinuation.

Characterization of gabapentin use in Kentucky after reclassification as a Schedule V controlled substance

BACKGROUND

Owing to increasing concern over the potential for gabapentin misuse, gabapentin was reclassified as a schedule V controlled substance in Kentucky (July 2017).

OBJECTIVE

This study aimed to characterize gabapentin use among Kentucky residents in the first year after its scheduling.

METHODS

This study used Kentucky All Schedule Prescription Electronic Reporting data (2018). Gabapentin use was defined as having at least 1 dispensed gabapentin prescription, and high-dose gabapentin use was defined as an average daily dose of more than 3600 mg at the patient level. The prevalence of gabapentin use, concurrent use of gabapentin with opioid analgesics (OAs) (gabapentin-OA), and gabapentin with OAs and benzodiazepines (BDZs) (gabapentin-OA-BDZ) were assessed. Estimated prevalence rate ratio and its 95% CI were reported to compare gabapentin use rates across different demographic groups.

RESULTS

A total of 16% of all 2018 controlled substance prescriptions were for gabapentin, and approximately 20% of Kentucky residents with controlled substance prescriptions received gabapentin at least once in 2018. The overall prevalence of gabapentin use was 63 per 1000 residents, with the highest rates among residents aged 55-64 years (126.9 per 1000). The prevalence of gabapentin use was higher in females (74.6 per 1000) versus males (50.6 per 1000) and in residents living in the Appalachian region (88.57 per 1000) versus Central (51.78 per 1000) and Delta (66.41 per 1000) regions. Among gabapentin users, 1% were high-dose users; 27.4% and 11.9% received gabapentin-OA or gabapentin-OA-BDZ concurrently, respectively. As the average daily dose increased from less than 900 mg to high-dose, the percentage of concurrent gabapentin-OA use increased from 13.4% to 50.7%.

CONCLUSION

Gabapentin is widely prescribed in Kentucky, with higher rates of use observed in females, those older than 55 years and individuals living in the Appalachian region. Concurrent use of gabapentin and OAs is common, especially in those receiving high-dose gabapentin. Future studies are needed to assess the risks associated with gabapentin use.

Gabapentinoid misuse, abuse and non-prescribed obtainment in a United States general population sample

Background Reports of gabapentinoid (gabapentin and pregabalin) misuse are on the rise, but few studies have assessed this within the general US population. Objective Describe lifetime misuse/abuse/non-prescribed obtainment of gabapentinoids and descriptive characteristics associated with such actions in a US general population sample. Setting This cross-sectional questionnaire was administered online by Qualtrics^® research panel aggregator via quota-based sampling. Methods Data were collected from a sample of respondents that mirrored the general US population aged 18-59 years with regards to age, geographic region, ethnicity, income, and education level, based on most recent census data. Misuse/abuse/non-prescribed obtainment was collectively defined as use of a gabapentinoid for reasons other than a diagnosed medical condition, using with the intention of altering one's state of consciousness, or obtaining without a prescription. A multivariable logistic regression model was created to predict misuse/abuse/non-prescribed obtainment of gabapentinoids, incorporating relevant covariates. Main outcome measure Proportion of sample indicating lifetime misuse/abuse/non-prescribed obtainment of gabapentinoids. Results Among 1,843 respondents, 121 (6.6%) reported gabapentinoid misuse/abuse/non-prescribed obtainment. Specifically, 2.1% (n = 39) and 1.5% (n = 27) of respondents for gabapentin and pregabalin, respectively, met study criteria for abuse. Opioids were the most common medication co-administered with gabapentinoids (among 50-70% of respondents) for misuse/abuse. Previous treatment for addiction (OR: 2.61, 95% CI: 1.32-5.14, p = 0.005) and the total attitudinal risk score (OR: 1.14, 95% CI: 1.09-1.19, p < 0.001) were associated with gabapentinoid misuse/abuse/non-prescribed obtainment. Conclusion Among those surveyed, 6.6% reported previous gabapentinoid misuse/abuse/non-prescribed obtainment, providing one of the first estimates within a nationally distributed, US general population sample.

Beyond Amitriptyline: A Pediatric and Adolescent Oriented Narrative Review of the Analgesic Properties of Psychotropic Medications for the Treatment of Complex Pain and Headache Disorders

Children and adolescents with recurrent or chronic pain and headache are a complex and heterogenous population. Patients are best served by multi-specialty, multidisciplinary teams to assess and create tailored, individualized pain treatment and rehabilitation plans. Due to the complex nature of pain, generalizing pharmacologic treatment recommendations in children with recurrent or chronic pains is challenging. This is particularly true of complicated patients with co-existing painful and psychiatric conditions. There is an unfortunate dearth of evidence to support many pharmacologic therapies to treat children with chronic pain and headache. This narrative review hopes to supplement the available treatment options for this complex population by reviewing the pediatric and adult literature for analgesic properties of medications that also have psychiatric indication. The medications reviewed belong to medication classes typically described as antidepressants, alpha 2 delta ligands, mood stabilizers, anti-psychotics, anti-sympathetic agents, and stimulants.

Treating Perioperative and Acute Pain in Patients on Buprenorphine: Narrative Literature Review and Practice Recommendations

Opioid use disorder (OUD), a leading cause of morbidity and mortality in the USA, can be effectively treated with buprenorphine. However, the same pharmacologic properties (e.g., high affinity, partial agonism, long half-life) that make it ideal as a treatment for OUD often cause concern among clinicians that buprenorphine will prevent effective management of acute pain with full agonist opioid analgesics. Because of this concern, many patients are asked to stop buprenorphine preoperatively or at the onset of acute pain, placing them at high risk for both relapse and a difficult transition back to buprenorphine after acute pain has resolved. The purpose of this review is to summarize the existing literature for acute pain and perioperative management in patients treated with buprenorphine for OUD and to provide practical management recommendations for generalist practitioners based on evidence and clinical experience. In short, evidence suggests that sufficient analgesia can be achieved with maintenance of buprenorphine and use of both opioid and non-opioid analgesic options for breakthrough pain. We recommend that clinicians (1) continue buprenorphine in the perioperative or acute pain period for patients with OUD; (2) use a multi-modal analgesic approach; (3) pay attention to care coordination and discharge planning when making an analgesic plan for patients with OUD treated with buprenorphine; and (4) use an individualized approach founded upon shared decision-making. Clinical examples involving mild and severe pain are discussed to highlight important management principles.

Current Evidence on Abuse and Misuse of Gabapentinoids

This review summarizes current evidence on the abuse and misuse of the gabapentinoids pregabalin and gabapentin. Pharmacovigilance studies, register-based studies, surveys, clinical toxicology studies, and forensic toxicology studies were identified and scrutinized with the goal to define the problem, identify risk factors, and discuss possible methods to reduce the potential for abuse and misuse. Studies found that gabapentinoids are abused and misused and that individuals with a history of psychiatric disorders or substance use disorder seem to be at high risk. Moreover, some evidence supports the notion that patients with opioid use disorders may be at an increased risk of abusing gabapentinoids. Available evidence also suggests that abuse and misuse are more frequent in users of pregabalin compared with users of gabapentin. Health professionals and prescribers should be aware of the risk for misuse of pregabalin and gabapentin, which eventually could lead to abuse, substance dependence, and intoxications. Prescribing to patients belonging to risk populations such as those with psychiatric disorders or substance use disorder should be avoided if possible and, if prescribed, signs of misuse and abuse should be monitored.

Prescription medicine misuse in the Asia-Pacific region: An evolving issue?

Prescription medicine misuse, especially misuse of opioids has become a major public healthcare issue in many developed countries such as the USA and Australia where this is associated with significant morbidity (Emergency Department visits due to acute toxicity) and mortality. In this review, we looked at the available data obtained from peer-reviewed articles and population surveys to gain an insight into the current situation in the Asia-Pacific region. There is currently limited information available, but data from subpopulation surveys in a number of countries suggests that prescription medicine misuse is likely to be an issue of concern from a public health perspective in the Asia-Pacific region. The available data suggest that misuse prevalence rates and the medicines that are commonly misused are similar to countries such as the USA and UK. Further studies are required to determine the overall prevalence of misuse, the harms associated with this and the sources of drugs being misused so that appropriate interventions can be implemented to tackle issues related to prescription medicine misuse in this region.

Abuse and Misuse of Pregabalin and Gabapentin: A Systematic Review Update

BACKGROUND

A 2017 systematic review (SR) identified 59 studies examining gabapentinoid (pregabalin and gabapentin) misuse/abuse. Evidence of gabapentinoid misuse/abuse has since grown substantially.

OBJECTIVE

Update previous SR and describe new insights regarding gabapentinoid abuse.

METHODS

A SR of PubMed was conducted to identify studies published from 7/29/2016-8/31/2020. Four searches were performed using the following terms: "gabapentin [MeSH] OR pregabalin [MeSH] OR gabapentinoid" AND one of the following substance misuse/abuse-related terms: "substance-related disorders [MeSH]", "overdose", "abuse", or "misuse". Clinicaltrials.gov and the Cochrane Library database were searched to identify ongoing studies or similar SRs. Reference lists of included studies were reviewed to identify additional literature. All studies with novel data related to pregabalin and/or gabapentin abuse, misuse, or overdose conducted during the study period were included. Articles not written in English, review articles, and animal studies were excluded.

RESULTS

Fifty-five studies were included (29 [52.7%] from North America, 17 [30.9%] Europe, 6 [10.9%] Asia, and 3 [5.5%] Australia). Forty-six observational studies and 10 case reports/series were included (one manuscript included both). Twenty (36.4%) studied gabapentin only, 18 (32.7%) pregabalin only, and 17 (30.9%) both pregabalin/gabapentin. These studies corroborate findings from the previous SR that gabapentinoids are increasingly abused or misused to self-medicate, that gabapentinoids can produce desirable effects alone but are often used concomitantly with other drugs, and that opioid use disorder is the greatest risk factor for gabapentinoid abuse. While the original SR identified the largest studies having been published in Europe, this review identified several more generalisable US studies that have subsequently been conducted. The most concerning finding was increased evidence of associated patient harm, including increased hospital utilisation and opioid-related overdose mortality risk.

CONCLUSION

Evidence suggests that gabapentinoid misuse/abuse represents a growing trend that is causing significant patient harm. Prescribers should exercise appropriate caution with use in high-risk populations and monitor for signs of misuse or abuse.

Chronic Post-Surgical Pain in the Frail Older Adult

Older adults are the fastest growing segment of the population and surgical procedures in this group increase each year. Chronic post-surgical pain is an important consideration in the older adult as it affects recovery, physical functioning, and overall quality of life. It is increasingly recognized as a public health issue but there is a need to improve our understanding of the disease process as well as the appropriate treatment and prevention. Frailty, delirium, and cognition influence post-operative outcomes in older adults and have been implicated in the development of chronic post-surgical pain. Further research must be conducted to fully understand the role they play in the occurrence of chronic post-surgical pain in the older adult. Additionally, careful attention must be given to the physiologic, cognitive, and comorbidity differences between the older adult and the general population. This is critical for elucidating the proper chronic post-surgical pain treatment and prevention strategies to ensure that the older adult undergoing surgical intervention will have an appropriate and desirable post-operative outcome.

Median Nerve Stimulation as a Nonpharmacological Approach to Bypass Analgesic Tolerance to Morphine: A Proof-of-Concept Study in Mice

Analgesic tolerance to opioids contributes to the opioid crisis by increasing the quantity of opioids prescribed and consumed. Thus, there is a need to develop non-opioid-based pain-relieving regimens as well as strategies to circumvent opioid tolerance. Previously, we revealed a non-opioid analgesic mechanism induced by median nerve electrostimulation at the overlaying PC6 (Neiguan) acupoint (MNS-PC6). Here, we further examined the efficacy of MNS-PC6 in morphine-tolerant mice with neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve. Daily treatments of MNS-PC6 (2 Hz, 2 mA), but not electrostimulation at a nonmedian nerve-innervated location, for a week post-CCI induction significantly suppressed established mechanical allodynia in CCI-mice in an orexin-1 (OX₁) and cannabinoid-1 (CB₁) receptor-dependent fashion. This antiallodynic effect induced by repeated MNS-PC6 was comparable to that induced by repeated gabapentin (50 mg/kg, i.p.) or single morphine (10 mg/kg, i.p.) treatments, but without tolerance, unlike repeated morphine-induced analgesia. Furthermore, single and repeated MNS-PC6 treatments remained fully effective in morphine-tolerant CCI-mice, also in an OX₁ and CB₁ receptor-dependent fashion. In CCI-mice receiving escalating doses of morphine for 21 days (10, 20 and 50 mg/kg), single and repeated MNS-PC6 treatments remained fully effective. Therefore, repeated MNS-PC6 treatments induce analgesia without tolerance, and retain efficacy in opioid-tolerant mice via a mechanism that involves OX₁ and CB₁ receptors. This study suggests that MNS-PC6 is an alternative pain management strategy that maybe useful for combatting the opioid epidemic, and opioid-tolerant patients receiving palliative care. PERSPECTIVE: Median nerve stimulation relieves neuropathic pain in mice without tolerance and retains efficacy even in mice with analgesic tolerance to escalating doses of morphine, via an opioid-independent, orexin-endocannabinoid-mediated mechanism. This study provides a proof of concept for utilizing peripheral nerve stimulating devices for pain management in opioid-tolerant patients.

Prescribing patterns of opioids and adjunctive analgesics for patients with burn injuries

PURPOSE

Large quantities of analgesics are prescribed to control pain among patients with burn injuries and may lead to chronic use and dependency. This study aimed to determine whether patients are overprescribed analgesics at discharge and to identify factors that influence prescribing patterns.

MATERIAL AND METHODS

A retrospective review of patient charts (n = 199) between July 1, 2015-2018 were reviewed from a registry at a single burn center. Opioid, neuropathic pain agent, acetaminophen, and ibuprofen quantities given before and at discharge were compared. Linear mixed regression models were used to identify factors that increased the amount of analgesics prescribed.

RESULTS

On average, patients were prescribed significantly more analgesics at discharge compared to what was consumed pre-discharge (p < 0.0001). Specifically, on average, providers did not overprescribe the daily dose, but overprescribed the duration of pain medications required. For every increase in percent TBSA, 14 MEQ more opioids, 203 mg more neuropathic pain agents, 843 mg more acetaminophen, and 126 mg more ibuprofen were prescribed (p < 0.05). Surgery was a predictor for higher opioid and neuropathic pain agent prescriptions (p = 0.03), while length of stay was associated with fewer neuropathic pain agents prescribed (p = 0.04). Fewer ibuprofen were given to patients with a history of substance misuse (p = 0.01).

CONCLUSIONS

The quantity of analgesics prescribed at discharge varied widely and often prescribed for long durations of time. Standardized prescribing guidelines should be developed to optimize how analgesics are prescribed at discharge.

A study of the reasons for prescribing and misuse of gabapentinoids in prison including their co-prescription with opioids and antidepressants

PURPOSE

Electronic medical case files of male prisoners in a category B prison in London were studied to establish a prevalence during an eight-month period of the use of and the reasons for prescribing gabapentinoids in prison and also to establish prescribing standards in prison and compliance with these. In addition, the prevalence of co-prescription of gabapentinoids with opioids and antidepressants, particularly tricyclic antidepressants such as amitriptyline, was also assessed in light of the increased risk of respiratory depression resulting in death when these drugs are used in combination. The paper aims to discuss these issues.

DESIGN/METHODOLOGY/APPROACH

A retrospective, SystmOne case-file based survey was undertaken searching by SNOMED CT supplemented by examination of free text, in a category B prison for males (Capacity 1,500 prisoners; Average turnover of prisoners up to 6,000 per year), to establish practice standards related to the prescription of Gabapentinoids in the prison and determine compliance with these.

FINDINGS

In total, 109 cases were identified of prisoners having been prescribed gabapentinoids, pregabalin in 66 cases (61 per cent) and gabapentin in 43 cases (39 per cent). In 36 cases (33 per cent) prescriptions were for unlicensed indications. This in fact represented 50 per cent of the cases where the indications were documented. In 51 cases (47 per cent) gabapentinoids were prescribed with an opioid substitute. In 14 cases (13 per cent), prescribed gabapentinoids were diverted to other prisoners.

PRACTICAL IMPLICATIONS

The initiation of gabapentinoids in prison should be avoided. For prisoners who are also receiving opioid substitutes or are abusing opiates, it may be unsafe to continue on gabapentinoids. Issues raised by this study are likely to apply to other prisons, secure forensic psychiatric facilities and indeed community mental health and primary care as well.

SOCIAL IMPLICATIONS

Risk of dependance on gabapentinoids including risk of mortality when taken with opioids and opioid substitutes.

ORIGINALITY/VALUE

This is an original study conducted at a category B prison in London.

Evidence-Based Pharmacotherapies for Alcohol Use Disorder: Clinical Pearls

Pathologic alcohol use affects more than 2 billion people and accounts for nearly 6% of all deaths worldwide. There are three medications approved for the treatment of alcohol use disorder by the US Food and Drug Administration (FDA): disulfiram, naltrexone (oral and long-acting injectable), and acamprosate. Of growing interest is the use of anticonvulsants for the treatment of alcohol use disorder, although currently none are FDA approved for this indication. Baclofen, a γ-aminobutyric acid B receptor agonist used for spasticity and pain, received temporary approval for alcohol use disorder in France. Despite effective pharmacotherapies, less than 9% of patients who undergo any form of alcohol use disorder treatment receive pharmacotherapies. Current evidence does not support the use of pharmacogenetic testing for treatment individualization. The objective of this review is to provide knowledge on practice parameters for evidenced-based pharmacologic treatment approaches in patients with alcohol use disorder.

Current and potential pharmacological treatment options for insomnia in patients with alcohol use disorder in recovery

Alcohol use disorder (AUD) is characterized by dysfunction in motivational, mood-stress regulation, and sleep systems that interact in complex ways to heighten the risk of relapse during abstinence. Emerging data suggest that excessive and chronic alcohol use disrupts sleep homeostasis and, in abstinence, subjects with AUD are known to experience insomnia that may persist for weeks to years, which we propose to refer to as insomnia associated with alcohol cessation (IAAC). The purpose of this review is to provide an update of pharmacological approaches to therapy including compounds in development, to raise awareness of the prevalence of and unmet need in IAAC and highlight differences in treatment consideration for IAAC as compared to insomnia disorder. We performed a search of select electronic databases to identify studies of pharmacological agents used to treat sleep disturbances in abstinent or treatment-seeking patients with alcohol use disorder. The search, conducted in June 2019 and updated in December 2019, yielded 1,188 abstracts after duplicates were removed, of which 36 full-text articles were assessed for eligibility. Eighteen studies were included, 15 randomized controlled trials and three open-label studies. Several classes of medications including antidepressants, anticonvulsants, and antipsychotics have been evaluated for their effectiveness in treating sleep disturbances in abstinent or treatment-seeking patients with AUD. None of these medications are approved by the FDA for the treatment of IAAC, and the currently available evidence for these agents is limited. Randomized, controlled clinical trials are warranted to evaluate the efficacy and safety of medications in the treatment of IAAC.

Safety of Gabapentin Prescribed for Any Indication in a Large Clinical Cohort of 571,718 US Veterans with and without Alcohol Use Disorder

BACKGROUND

Gabapentin is prescribed for seizures and pain and has efficacy for treating alcohol use disorder (AUD) starting at doses of 900 milligrams per day (mg/d). Recent evidence suggests safety concerns associated with gabapentin including adverse neurologic effects. Individuals with hepatitis C (HCV), HIV, or AUD may be at increased risk due to comorbidities and potential medication interactions.

METHODS

We identified patients prescribed gabapentin for ≥ 60 days for any indication between 2002 and 2015. We propensity-score matched each gabapentin-exposed patient with up to 5 gabapentin-unexposed patients. We followed patients for 2 years or until diagnosed with (i) falls or fractures, or (ii) altered mental status using validated ICD-9 diagnostic codes. We used Poisson regression to estimate incidence rates and relative risk (RR) of these adverse events in association with gabapentin exposure overall and stratified by age, race/ethnicity, sex, HCV, HIV, AUD, and dose.

RESULTS

Incidence of falls or fractures was 1.81 per 100 person-years (PY) among 140,310 gabapentin-exposed and 1.34/100 PY among 431,408 gabapentin-unexposed patients (RR 1.35, 95% confidence interval [CI] 1.28 to 1.44). Incidence of altered mental status was 1.08/100 PY among exposed and 0.97/100 PY among unexposed patients, RR of 1.12 (95% CI 1.04 to 1.20). Excess risk of falls or fractures associated with gabapentin exposure was observed in all subgroups except patients with HCV, HIV, or AUD; however, these groups had elevated incidence regardless of exposure. There was a clear dose-response relationship for falls or fractures with highest risk observed among those prescribed ≥ 2,400 mg/d (RR 1.90, 95% CI 1.50 to 2.40). Patients were at increased risk for altered mental status at doses 600 to 2,399 mg/d; however, low number of events in the highest dose category limited power to detect a statistically significant association ≥ 2,400 mg/d.

CONCLUSIONS

Gabapentin is associated with falls or fractures and altered mental status. Clinicians should be monitoring gabapentin safety, especially at doses ≥ 600 mg/d, in patients with and without AUD.

Directive clinique no 405 : Dépistage et conseils en matière de consommation d'alcool pendant la grossesse

OBJECTIF

Établir des normes pancanadiennes fondées sur les meilleures données probantes actuelles sur le dépistage et les conseils en matière de consommation d'alcool et de troubles de consommation d'alcool chez les femmes enceintes ou en âge de procréer. PROFESSIONNELS CONCERNéS: Les fournisseurs de soins qui prodiguent des soins aux femmes enceintes et aux femmes en âge procréer.

POPULATION CIBLE

Les femmes enceintes, les femmes en âge de procréer et leurs familles. DONNéES PROBANTES: Des recherches ont été effectuées dans les bases de données Medline, Embase et CENTRAL avec le thème « alcohol use and pregnancy ». Les résultats ont été filtrés de façon à obtenir des publications parues entre 2010 et septembre 2018. Les termes de recherche ont été mis au point à partir des termes du thésaurus de référence biomédicale MeSH et de mots clés, dont les suivants : pre-pregnancy, pregnant, breastfeeding, lactation, female, women, preconception care, prenatal care, fetal alcohol spectrum disorder, prenatal alcohol exposure, drinking behavior, alcohol abstinence, alcohol drinking, binge drinking, alcohol-related disorders, alcoholism, alcohol consumption, alcohol abuse, benzodiazepines, disulfiram, naltrexane, acamprosate, ondansetron, topiramate, cyanamide, calcium carbimide, alcohol deterrents, disease management, detoxification, Alcoholics Anonymous, alcohol counselling, harm reduction, pre-pregnancy care, prenatal care, incidence, prevalence, epidemiological monitoring et brief intervention. Les données probantes retenues proviennent d'essais cliniques, d'études observationnelles, de revues de la littérature, d'analyses systématiques et méta-analyses, de lignes directrices et de conférences de consensus. MéTHODES DE VALIDATION: Les auteurs ont rédigé et accepté le contenu et les recommandations de la présente directive. Le conseil d'administration de la Société des obstétriciens et gynécologues du Canada a approuvé la version définitive aux fins de publication. La qualité des données probantes a été évaluée au moyen des critères de l'approche GRADE (Grading of Recommendations Assessment, Development, and Evaluation) (consulter les tableaux A1 et A2 de l'annexe en ligne). BéNéFICES, RISQUES, COûTS: La mise en œuvre des recommandations de la présente directive à l'aide d'outils de dépistage validés et de stratégies d'intervention brève peut améliorer la capacité des fournisseurs de soins obstétricaux à reconnaître la consommation d'alcool et la consommation problématique d'alcool chez les femmes enceintes ou en âge de procréer. Il est attendu des fournisseurs de soins de santé qu'ils deviennent confiants et compétents en matière de prise en charge et de soutien de ces femmes afin qu'elles puissent avoir la meilleure santé possible et une issue de grossesse optimale. DÉCLARATIONS SOMMAIRES (CLASSEMENT GRADE ENTRE PARENTHèSES): RECOMMANDATIONS (CLASSEMENT GRADE ENTRE PARENTHèSES).

Acquired platelet defect associated with gabapentin treatment: a case-report

Gabapentin, a structural analog of gamma-aminobutyric acid, is used to treat peripheral neuropathic pain. Here we report the first case of platelet function disorder associated with gabapentin treatment in a 44-year-old woman without a history of bleeding. She presented with mucocutaneous bleeding approximately 1 month after initiation of gabapentin and platelet function tests showed no aggregation to arachidonic acid and epinephrine, a defective response to ADP and a slightly decreased response to collagen. Gabapentin's imputability was supported by the fact that all platelet functions were normalized 6 days after drug discontinuation, with the simultaneous disappearance of bleedings.

Pharmacotherapies and personalized medicine for alcohol use disorder: a review

Alcohol use disorder (AUD) is highly prevalent and among the leading causes of morbidity and mortality in the United States. Pharmacotherapies for AUD are limited, thus making identification of patient subgroups that are most likely to respond favorably crucial. In this article, pharmacogenetic research on US FDA-approved and commonly prescribed off-label medications for the treatment of AUD is comprehensively reviewed. While the field has advanced in understanding pharmacotherapies for AUD and potential genetic moderators of treatment responses, the pharmacogenetic data to guide the prescribing clinician are limited and should be interpreted with caution. Precision medicine for AUD with more beneficial treatment responses and minimal side effects remains a high priority for further research.

Descriptions of Gabapentin Misuse and Associated Behaviors among a Sample of Opioid (Mis)users in South Florida

Gabapentin has received increased attention due to a growing number of reports of misuse and diversion. However, significant details about gabapentin misuse are scant. Data are drawn from a mixed-methods study examining gabapentin misuse in South Florida. The sample includes 49 respondents who were age 18 or over and reported past year use of illicit opioids and/or the misuse of prescription opioid medications, as well as, recent (past 90 days) gabapentin misuse. Respondents were female (40.8%), Hispanic (30.6%), Black (16.3%), white (49.0%), and other race/ethnicity (4.1%). Mean age was 37.6. Many respondents (43%) misused gabapentin without ever receiving a prescription and 14% misused prior to being prescribed. Mean frequency of recent misuse was 25.4 days and included a mean of 51.65 pills/doses. Prevalent routes of administration included swallowing (85.7%) and snorting (10.2%). Gabapentin misuse occurred concomitantly with any opioid (44.9%), benzodiazepines (38.8%), alcohol (24.5%), and powder cocaine (24.5), among others. Respondents' descriptions indicate that gabapentin produces feelings reminiscent of alcohol intoxication or opioid-induced euphoria, but for some it produces no noticeable effect or only alleviates pain. Greater understanding of gabapentin misuse, especially associated behaviors and concomitant use is needed to inform prevention and intervention efforts, and to guide policy approaches.

Inappropriate Preoperative Gabapentinoid Use Among Patients With Carpal Tunnel Syndrome

PURPOSE

Gabapentinoids are commonly prescribed for the treatment of neuropathic pain but are not recommended for the primary treatment of carpal tunnel syndrome (CTS). We sought (1) to investigate the preoperative use of gabapentinoids for the treatment of CTS and (2) to determine whether preoperative exposure is associated with persistent gabapentinoid and opioid use after carpal tunnel release.

METHODS

We performed a retrospective cohort study using IBM MarketScan Research Databases (2010-2017) of patients who did not fill a gabapentinoid or opioid prescription within 3 months of a new CTS diagnosis undergoing surgical release. Our primary outcomes included preoperative gabapentinoid prescription fills associated with CTS and persistent prescription fills of gabapentinoids and opioids at 91 to 180 days after surgery. Multivariable logistic regression models were used to evaluate the association between patient-level factors and persistent gabapentinoid and opioid use.

RESULTS

Of the 56,593 patients without a previous gabapentinoid or opioid prescription prior to diagnosis of CTS, 3,474 patients (6%) filled a gabapentinoid prescription before carpal tunnel release. Overall, 835 patients (24% of the preoperative users) continued to fill gabapentinoid prescriptions at 91 to 180 days after surgery. Of the preoperative gabapentinoid users, 20% (702 patients) continued to fill opioid prescriptions at 91 to 80 days after release. After adjusting for patient characteristics, preoperative gabapentinoid use was associated with increased odds of persistent postoperative gabapentinoid use (preoperative gabapentinoid, 22% adjusted probability; 95% confidence interval [95% CI], 20.3%-23.0%, no preoperative gabapentinoid use, 1%; 95% CI, 1.2%-1.4%) and persistent postoperative opioid use (preoperative gabapentinoid, 18% adjusted probability; 95% CI, 17%-20%), no preoperative gabapentinoid, 9%; 95% CI, 8.6%-9.1%).

CONCLUSIONS

Despite a lack of evidence to support the use of gabapentinoids for CTS, 6% of patients are prescribed a gabapentinoid prior to surgery, and prolonged use is common. Given the effectiveness of surgical release and the risks associated with gabapentinoids, greater attention is needed to ensure that gabapentinoids are prescribed appropriately, avoided when possible, and stopped after surgery.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Gabapentin-induced drug-seeking-like behavior: a potential role for the dopaminergic system

Drugs of abuse represent a growing public health crisis. Accumulating evidence indicates that gabapentin (GBP), a prescription drug, is prone to misuse, abuse, withdrawal, and dependence. Commonly, drugs of abuse modulate the dopaminergic system to induce addiction. In this study, we used the conditioned place preference (CPP) model to investigate the involvement of the dopamine 1 (D1) receptor on the reward and reinforcement behavior of GBP. Under a CPP paradigm, male BALB/c mice were intraperitoneally injected either saline or 100, 200, or 300 mg/kg of GBP and confined to the injection-paired chamber for 30 min. In the pre-conditioning phase, mice were conditioned for 3 days, and baseline data were collected. In the conditioning phase, mice were given once-daily alternating injections of either GBP or saline for 8 days and subsequently assessed in a post-conditioning test. Injections of 300 mg/kg of GBP significantly increased the time spent in the drug-paired chamber compared to the saline-paired chamber. However, lower doses of GBP (100 and 200 mg/kg) showed no effect. Pre-treatment with SKF-83566, a D1 receptor antagonist, attenuated GBP-induced CPP. Thus, for the first time, we show that GBP can induce CPP through a dopaminergic-dependent mechanism.

Perioperative Use of Gabapentinoids for the Management of Postoperative Acute Pain

Background

Widely used for acute pain management, the clinical benefit from perioperative use of gabapentinoids is uncertain. The aim of this systematic review was to assess the analgesic effect and adverse events with the perioperative use of gabapentinoids in adult patients.

Methods

Randomized controlled trials studying the use of gabapentinoids in adult patients undergoing surgery were included. The primary outcome was the intensity of postoperative acute pain. Secondary outcomes included the intensity of postoperative subacute pain, incidence of postoperative chronic pain, cumulative opioid use, persistent opioid use, lengths of stay, and adverse events. The clinical significance of the summary estimates was assessed based on established thresholds for minimally important differences.

Results

In total, 281 trials (N = 24,682 participants) were included in this meta-analysis. Compared with controls, gabapentinoids were associated with a lower postoperative pain intensity (100-point scale) at 6 h (mean difference, −10; 95% CI, −12 to −9), 12 h (mean difference, −9; 95% CI, −10 to −7), 24 h (mean difference, −7; 95% CI, −8 to −6), and 48 h (mean difference, −3; 95% CI, −5 to −1). This effect was not clinically significant ranging below the minimally important difference (10 points out of 100) for each time point. These results were consistent regardless of the type of drug (gabapentin or pregabalin). No effect was observed on pain intensity at 72 h, subacute and chronic pain. The use of gabapentinoids was associated with a lower risk of postoperative nausea and vomiting but with more dizziness and visual disturbance.

Conclusions

No clinically significant analgesic effect for the perioperative use of gabapentinoids was observed. There was also no effect on the prevention of postoperative chronic pain and a greater risk of adverse events. These results do not support the routine use of pregabalin or gabapentin for the management of postoperative pain in adult patients.

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Trends in gabapentinoid prescribing, co-prescribing of opioids and benzodiazepines, and associated deaths in Scotland

BACKGROUND

Gabapentinoid drugs (gabapentin and pregabalin) are effective in neuropathic pain, which has a prevalence of ∼7%. Concerns about increased prescribing have implications for patient safety, misuse, and diversion. Drug-related deaths (DRDs) have increased and toxicology often implicates gabapentinoids. We studied national and regional prescribing rates (2006-2016) and identified associated sociodemographic factors, co-prescriptions and mortality, including DRDs.

METHODS

National data from the Information Service Division, NHS Scotland were analysed for prescribing, sociodemographic, and mortality data from the Health Informatics Centre, University of Dundee. DRDs in which gabapentinoids were implicated were identified from National Records of Scotland and Tayside Drug Death Databases.

RESULTS

From 2006 to 2016, the number of gabapentin prescriptions in Scotland increased 4-fold (164 630 to 694 293), and pregabalin 16-fold (27 094 to 435 490). In 2016 'recurrent users' (three or more prescriptions) had mean age 58.1 yr, were mostly females (62.5%), and were more likely to live in deprived areas. Of these, 60% were co-prescribed an opioid, benzodiazepine, or both (opioid 49.9%, benzodiazepine 26.8%, both 17.1%). The age-standardised death rate in those prescribed gabapentinoids was double that in the Scottish population (relative risk 2.16, 95% confidence interval 2.08-2.25). Increases in gabapentinoids contributing to cause of DRDs were reported regionally and nationally (gabapentin 23% vs 15%; pregabalin 21% vs 7%). In Tayside, gabapentinoids were implicated in 22 (39%) of DRDs, 17 (77%) of whom had not received a prescription.

CONCLUSIONS

Gabapentinoid prescribing has increased dramatically since 2006, as have dangerous co-prescribing and death (including DRDs). Older people, women, and those living in deprived areas were particularly likely to receive prescriptions. Their contribution to DRDs may be more related to illegal use with diversion of prescribed medication.

Emerging roles for α2δ subunits in calcium channel function and synaptic connectivity

Central nervous system function requires the proper formation and function of synapses. The α2δ auxiliary subunits of voltage-gated calcium channels have emerged as regulators of a number of critical events associated with regulation of synaptic function, including channel trafficking and localization, as well as the initial establishment of synaptic structures. In this review, we will discuss some of these recent studies which have uncovered novel mechanisms for α2δ function at the synapse, including the regulation of calcium channel α1 subunit specificity and the promotion of dendritic spine growth. Moreover, we will cover recent advances that have been made in understanding the consequences of aberrant α2δ signaling in injury and disease.

Clinical and basic research investigations into the long-term effects of prenatal opioid exposure on brain development

Coincident with the opioid epidemic in the United States has been a dramatic increase in the number of children born with neonatal abstinence syndrome (NAS), a form of withdrawal resulting from opioid exposure during pregnancy. Many research efforts on NAS have focused on short-term care, including acute symptom treatment and weaning of the infants off their drug dependency prior to authorizing their release. However, investigations into the long-term effects of prenatal opioid exposure (POE) on brain development, from the cellular to the behavioral level, have not been as frequent. Given the importance of the perinatal period for human brain development, opioid-induced disturbances in the formation and function of nascent synaptic networks and glia have the potential to impact brain connectivity and cognition long after the drug supply is cutoff shortly after birth. In this review, we will summarize the current state of NAS research, bringing together findings from human studies and preclinical animal models to highlight what is known about how POE can induce significant, prolonged deficits in brain structure and function. With rates of NAS continuing to rise, particularly in regions that already face substantial socioeconomic challenges, we speculate as to the most promising avenues for future research to alleviate this growing multigenerational threat.