Prescribed and non-prescribed gabapentin use among persons seeking inpatient opioid detoxification

Gabapentinoids Increase the Potency of Fentanyl and Heroin and Decrease the Potency of Naloxone to Antagonize Fentanyl and Heroin in Rats Discriminating Fentanyl

Despite a significant decrease in the number of prescriptions for opioids, the opioid crisis continues, fueled in large part by the availability of the phenylpiperidine mu opioid receptor (MOR) agonist fentanyl. In contrast, the number of prescriptions for and the off-label use of gabapentinoids (gabapentin and pregabalin) has increased dramatically, with gabapentinoids commonly detected in opioid overdose victims. Although gabapentinoids can decrease the potency of the opioid receptor antagonist naloxone to reverse heroin-induced hypoventilation in male rats, the specificity and nature of interaction between gabapentinoids and MOR agonists and any potential sex difference in those interactions are not well characterized. Gabapentinoids were studied in female and male rats discriminating fentanyl (0.0032 mg/kg, i.p.) or cocaine (3.2 mg/kg, i.p.). Alone, neither gabapentin nor pregabalin significantly increased fentanyl- or cocaine-appropriate responding. In rats discriminating fentanyl, each gabapentinoid dose-dependently shifted the fentanyl and heroin discrimination dose-effect functions to the left, whereas naloxone dose-dependently shifted the fentanyl and heroin discrimination dose-effect functions to the right. Each gabapentinoid (100 mg/kg) significantly decreased the potency of naloxone to antagonize the discriminative stimulus effect of fentanyl or heroin. In contrast, each gabapentinoid dose-dependently shifted the cocaine and d-methamphetamine discrimination dose-effect functions to the right. There were no significant sex differences in this study. These results suggest that gabapentinoids impact the misuse of opioids, the co-use of opioids and stimulant drugs, and the increasing number of overdose deaths in individuals using opioids, stimulant drugs, and gabapentinoids in mixtures. SIGNIFICANCE STATEMENT: The number of prescriptions for and the off-label use of gabapentinoids (gabapentin and pregabalin) has increased dramatically, with gabapentinoids commonly detected in opioid overdose victims. This study reports that in rats gabapentinoids increase the potency of fentanyl and heroin to produce discriminative stimulus effects while decreasing the potency of naloxone to antagonize those effects of fentanyl and heroin. These results can help guide policies for regulating gabapentinoids and treating opioid misuse and overdose.

Systematic review: The relationship between gabapentinoids, etizolam, and drug related deaths in Scotland

In recent years Scotland has been experiencing a disproportionally high number of drug related deaths compared to other European countries, causing significant individual, societal and economic burden. A possible cause of this is the increase in average number of substances involved in Scottish drug related deaths, as well as the changing pattern of substances involved. Opioids, cocaine, and alcohol have been consistently involved in the culture of drug use in Scotland, however recently National Records Scotland have identified that designer benzodiazepines such as etizolam, and prescription drugs such as gabapentinoids are increasingly being detected in Scottish toxicology reports. A systematic literature review following PRISMA guidelines was conducted through searching PubMed and Google Scholar to identify peer-reviewed articles published in English between 2013 and 2023 that investigated Scottish population data on gabapentinoids and etizolam to establish their contribution to the rise in Scottish drug related deaths. 18 studies were included in the review. A high use prevalence of etizolam and gabapentinoids in Scotland has been identified, with both substance-related deaths showing recent increase, marked since 2015. This pattern is replicated in the Scottish prison system. There has also been a significant increase of gabapentinoids prescriptions in Scotland. Polydrug use was identified as the most common determinant of both etizolam and gabapentinoids related adverse effects and fatality in Scotland, especially concurrent opioid use. The results indicate the literature on individual characteristics of Scottish at-risk users of gabapentinoids and etizolam is limited, however the data shows both substances are being used by older cohort, with adverse effects seen more in older women.

Direct-To-Definitive Urine and Oral Fluid Test Results for Unscreened and Rarely Screened Drugs in Individuals Applying for Methadone Treatment in 7 U.S. States

The standard protocol in addiction treatment/pain management is to conduct immunoassay screens for major drugs subject to misuse, followed by confirmatory testing of positive results. However, this may miss unscreened or rarely screened drugs that could pose risks, especially to polydrug users. We sought to determine the prevalences of unscreened/rarely screened drugs in a sample of individuals misusing drugs in 7 U.S. states, and to compare the results of urine vs. oral testing for these drugs by direct-to-definitive liquid chromatography/tandem mass spectrometry (LC-MS-MS). The five drugs with the highest prevalences were: gabapentin (16.8%), quetiapine (6.2%), chlorpheniramine (5.3%), hydroxyzine (4.9%), and ephedrine (3.5%). All have clinical significance as indicated by severity of possible side effects, interactions with other drugs, and/or misuse potential. Drugs were generally detected more frequently in oral fluid than urine, but gabapentin was more frequently detected in urine. The prevalences of the included drugs seem high enough, and their clinical significance important enough, to warrant consideration of expanding clinical drug test panels, either by direct-to-definitive testing or the addition of selected immunoassay screens when available. Oral fluid was usually more suitable than urine as the test matrix, given the higher rates of detection in oral fluid for most substances included in this study.

Effects of Gabapentinoids on Heroin-Induced Ventilatory Depression and Reversal by Naloxone

Despite an increasing prevalence of gabapentinoids (gabapentin and pregabalin) in opioid overdose deaths, little research has evaluated potentially harmful interactions between gabapentinoids and opioids. This study sought to determine the effects of gabapentinoids on the ventilatory depressive effects of heroin and their reversal by naloxone. Rats were given gabapentin, pregabalin, or saline prior to receiving increasing doses of heroin while ventilation was monitored using whole-body plethysmography. In some sessions naloxone was administered following the largest dose of heroin. The primary outcomes of this study were minute volume and Pause. Heroin dose-dependently reduced minute volume and increased Pause. Administration of naloxone dose-dependently reversed the effects of heroin on ventilation. Gabapentinoids did not alter the ventilatory depressive effects of heroin alone but reduced the potency of naloxone to reverse heroin-induced ventilatory depression. These preliminary findings emphasize the need for further research evaluating interactions between gabapentinoids and opioids related to substance misuse and overdose.

Functional Impairment and Cognitive Symptoms Among People with HIV Infection on Chronic Opioid Therapy for Pain: The Impact of Gabapentin and Other Sedating Medications

Gabapentin is associated with dizziness, falls, and somnolence yet commonly prescribed to people with HIV (PWH) treated with chronic opioid therapy (COT). Physical function and cognition are understudied when prescribed together. Among PWH on COT, we evaluated whether co-prescribed gabapentin is associated with (a) functional impairment; (b) trouble thinking clearly; and (c) difficulty controlling drowsiness using logistic regression models adjusted for prescribed opioid dose, other (non-gabapentin) sedating medication, substance use disorder, and mental/physical health indicators in a cross-sectional study. Among 166 participants, 40% were prescribed gabapentin, 41% reported functional impairment, 41% trouble thinking clearly, and 38% difficulty controlling drowsiness. Gabapentin co-prescribed with COT was significantly associated with trouble thinking clearly but not with functional impairment or difficulty controlling drowsiness. Clinicians should be cognizant of potential problems with thinking clearly when co-prescribing gabapentin and opioid medication.

Nonmedical use of gabapentin and opioid agonist medications in treatment-seeking individuals with opioid use disorder

BACKGROUND

As prescriptions for gabapentin have increased in recent years, nonmedical use and risk of adverse outcomes (e.g., hospitalizations and overdose) have been identified, particularly in association with opioids, including opioid agonist medications (OAMs) buprenorphine and methadone. However, there is a lack of systematic, nationwide data assessing the relationship between the nonmedical use of gabapentin and OAMs.

METHODS

Data were sourced from two nationwide opioid surveillance programs of treatment-seeking individuals with opioid use disorder (OUD). Both programs utilized an identical serial, cross sectional survey of 12,792 new entrants to one of 163 substance use treatment programs for OUD in 46 states and the District of Columbia from January 2019 to December 2020.

RESULTS

Past month nonmedical use of gabapentin was endorsed by 9.3% of the sample. Of those using gabapentin nonmedically, 64.1% also endorsed nonmedical use of an OAM, including concomitant use of methadone (35.3%), and buprenorphine (49.0%). Concomitant nonmedical use of gabapentin and OAMs was more prevalent (versus nonmedical use of gabapentin alone) in the Southern region, among those living in a street dwelling, those with chronic pain and healthcare professionals.

CONCLUSIONS

Nonmedical use of gabapentin in people with OUD appears to frequently coincide with nonmedical use of OAMs. As prescriptions and off-label use of gabapentin increase, provider education should include the risks of concomitant gabapentin and OAM use, particularly amongst buprenorphine prescribers. Future research should investigate motivations (e.g., OUD self-management) for nonmedical use of gabapentin and OAMs within the context of OUD treatment access and retention.

Overdose deaths involving non-BZD hypnotic/sedatives in the USA: Trends analyses

Background

There is sparse knowledge on overdose deaths resulting from non-benzodiazepines and gabapentinoids usage. We examined overdose death rate across demographics categories and the overdose death trends over time.

Methods

Using data from the National Center for Health Statistics (USA), we identified 21,167 persons that died with an overdose ICD code as the underlying cause of death and had a T42.6/T42.7 ICD code, which include gabapentinoids and z-drugs, among their multiple causes of death. The overdose death rate was calculated per 100,000 persons for every year between 2000 and 2018. We used joinpoint regression analyses to assess trends over time.

Results

We identified a rise in the proportion of deaths with a T42.6/T42.7 ICD code between 2000 and 2006 (yearly change: +0.06) and between 2006 and 2015 (yearly change: +0.32). From 2000 to 2008, the proportion of deaths with any other T code rose significantly (yearly change: +3.56). Between 2008 and 2018, there was also a significant rise (yearly change: +1.31). From 2000 to 2015, the proportion of deaths with a T42.6/T42.7 ICD code with any other T code rose (yearly change: +2.58). From 2000 to 2015, the proportion of deaths with a T42.6/T42.7 ICD code with a concurrent benzodiazepine T code rose (yearly change: +1.98). From 2000 to 2005, the proportion of alcohol T codes rose non-significantly (yearly change: +0.35). Finally, the proportion of alcohol T codes fell significantly between 2008 and 2018 (yearly change: - 0.74).

Interpretation

Deaths due to non-benzodiazepine hypnotics and gabapentinoids increased significantly over the last two decades. Clinicians should not assume that replacing benzodiazepines and opioids with these medications necessarily lowers risk to the patient.

Funding

This study was funded by an internal grant from the Columbia University President's Global Innovation Fund (PI: Martins).

Empowering Nurses: Communicating Potential Medication Misuse

BACKGROUND

In nursing education and practice, we prepare nurses on topics such as patient care, pathophysiology, pharmacology, nursing leadership, and nursing competencies. Unfortunately, we may be missing the mark when it comes to integrating these topics and applying them to situations that arise in health care such as medication misuse. Nurses work intimately with patients and can recognize potential medication misuse by reviewing medication regimens and assessing necessity of PRN patient requests. In cases where nurses suspect misuse, they may or may not feel comfortable addressing these concerns with other members of the health care team.

AIMS

Study aims were to assess the baseline of whether nurses are comfortable with their level of skill to recognize potential patient medication misuse and to assess nurses' comfortability with communicating these concerns with other nurses, providers, and patients.

METHODS

This survey study was designed to obtain practical information about nurses understanding of misused and diverted prescription medications and level of comfort with expressing concerns about the use of central nervous system depressants to inform education, practice, and research. Three-hundred and fifty nurses at one hospital were invited to participate in an anonymous REDCap survey.

RESULTS

Thirty-five percent of the surveyed nurses returned the survey. Responding nurses were more comfortable sharing their own knowledge and the need for more education on the topic than they were discussing interdisciplinary communication.

CONCLUSIONS

Empowering nurses to communicate this knowledge with others on the health care team has major public health implications to reduce the negative outcomes of misused medications.

Managing the misuse potential and risk of psychological harm from gabapentinoids in primary care in New Zealand

Gabapentinoid prescribing is increasing in New Zealand. International evidence suggests that this prescribing trend is followed by increasing harms, including misuse, dependence, overdose, and psychological harms including suicidal thoughts or behaviours. However, there is limited guidance for prescribers on how to manage these potential harms. Here, we summarise the current international literature and identify three main risk factors that can be used for screening purposes when considering prescribing a gabapentinoid, to identify patients that may be at greater risk of harm. Based on current knowledge of harms, we provide guidance to prescribers on monitoring patients taking gabapentinoids. Finally, we summarise the evidence regarding tapering, and highlight key knowledge gaps including other interventions, referral, and data from primary care populations.

Consuming illicit opioids during a drug overdose epidemic: Illicit fentanyls, drug discernment, and the radical transformation of the illicit opioid market

BACKGROUND

North America continues to face an opioid overdose epidemic, driven by persistent increases in illicit fentanyls and fluctuations in potency leading to uncertainty for consumers. This qualitative study was conducted to better understand how people who inject drugs (PWID) came to recognize fentanyl as a growing adulterant of heroin and the subsequent sensory discernment strategies they employed to continue injecting. Our main objective was to investigate how observations and knowledge are combined as homegrown techniques for detecting fentanyl and minimizing risk. Secondary objectives were to examine the impact of growing fentanyl adulteration on individual drug use behavior.

METHODS

Between April and May 2019, 28 PWID (18 men, 10 women; average age = 38.43 years, SD = 9.26) were purposely recruited from a needle services program in Greensboro, North Carolina. Study participants were interviewed in-person using a qualitative, semi-structured instrument. Interviews were analyzed with a general inductive approach using NVivo12.

RESULTS

Participants described methods for detecting fentanyl in illicit opioids. Sudden increases in the potency of the 'rush' and sharp decreases in the length of the 'high' were chief indicators along with changes in drug color and texture. Heavy sedation was associated with fentanyl use and histamine-releasing effects characterized as 'pins and needles' were ascribed to injecting fentanyl as a component of the rush. Fentanyl's short high helped explain higher injection frequency and heavy sedation was the leading reason for co-using fentanyl with cocaine/crack or methamphetamine.

CONCLUSION

PWID have the capacity to recognize changes to the illicit opioid supply. Study participants navigated unpredictable fluctuations in the illicit opioid market by employing homegrown discernment techniques, modifying drug use behavior, and co-using non-opioid drugs. Researchers and policymakers should involve PWID as subject matter experts to help modernize harm reduction for the fentanyl age with practical strategies to boost resiliency and save lives.

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.

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.

Building and Testing PPARγ Therapeutic ELB00824 with an Improved Therapeutic Window for Neuropathic Pain

Effective, non-addictive therapeutics for chronic pain remain a critical need. While there are several potential therapeutics that stimulate anti-inflammatory mechanisms to restore homeostasis in the spinal dorsal horn microenvironment, the effectiveness of drugs for neuropathic pain are still inadequate. The convergence of increasing knowledge about the multi-factorial mechanisms underlying neuropathic pain and the mechanisms of drug action from preclinical studies are providing the ability to create pharmaceuticals with better clinical effectiveness. By targeting and activating the peroxisome proliferator-activated receptor gamma subunit (PPARγ), numerous preclinical studies report pleiotropic effects of thiazolidinediones (TDZ) beyond their intended use of increasing insulin, including their anti-inflammatory, renal, cardioprotective, and oncopreventative effects. Several studies find TDZs reduce pain-related behavioral symptoms, including ongoing secondary hypersensitivity driven by central sensitization. Previous studies find increased PPARγ in the spinal cord and brain regions innervated by incoming afferent nerve endings after the induction of neuropathic pain models. PPARγ agonist treatment provides an effective reduction in pain-related behaviors, including anxiety. Data further suggest that improved brain mitochondrial bioenergetics after PPARγ agonist treatment is a key mechanism for reducing hypersensitivity. This review emphasizes two points relevant for the development of better chronic pain therapies. First, employing neuropathic pain models with chronic duration is critical since they can encompass the continuum of molecular and brain circuitry alterations arising over time when pain persists, providing greater relevance to clinical pain syndromes. Assisting in that effort are preclinical models of chronic trigeminal pain syndromes. Secondly, considering the access to nerve and brain neurons and glia across the blood-brain barrier is important. While many therapies have low brain penetrance, a PPARγ agonist with better brain penetrance, ELB00824, has been developed. Purposeful design and recent comparative testing indicate that ELB00824 is extraordinarily efficient and efficacious. ELB00824 provides greatly improved attenuation of pain-related behaviors, including mechanical hypersensitivity, anxiety, and depression in our chronic trigeminal nerve injury models. Physiochemical properties allowing significant brain access and toxicity testing are discussed.