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

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.

"We were all looking for the magic pill": A qualitative study of patient experiences using gabapentinoids for chronic pain

BACKGROUND

Gabapentinoid medications are increasingly being used in chronic pain management, yet very little is known about the experiences of those using them. The aim of this study was to address this gap in the literature by qualitatively exploring the lived experiences of patients using gabapentinoids for chronic pain.

METHODS

Semi-structured interviews were conducted with 12 adults prescribed a gabapentinoid medication - either pregabalin or gabapentin - for chronic pain in Australia. Interviews were conducted in May 2022 via telephone or online video chat. Audio recordings of the interviews were transcribed verbatim, and data were analysed using reflexive thematic analysis. The Medication Adherence Model was used as a framework for synthesising the data and organising themes.

RESULTS

For participants in this study, the initial decision to use gabapentinoids for chronic pain was driven by a level of desperation for pain relief, a perceived lack of pain management alternatives, and a belief that the medication was safer and easier to access than opioids. However, once using gabapentinoids, experiences varied considerably with some viewing the medication as effective and safe, and others viewing it as useless or harmful. Some participants expressed concern that they were not adequately informed by their prescribers about the risks of gabapentinoid use.

CONCLUSION

These findings emphasise the importance of patient-provider communication and taking a patient-centred approach to gabapentinoid prescribing and de-prescribing. Future qualitative research in this area should involve primary care providers to gain a better understanding of factors driving increased gabapentinoid prescribing in chronic pain management as well as barriers to patient education.

Trends in overdose deaths involving gabapentinoids and Z-drugs in the United States

INTRODUCTION

As policies have been implemented to limit access to prescription opioids, other drugs have been prescribed off-label, sometimes concurrently with opioids, to manage pain. There are concerns about the use of gabapentinoids and "Z-drugs" with opioids. As the opioid crisis transitions to illicit opioids and polysubstance use, little work quantifies the concurrent involvement of non-opioid prescription drugs and illicit opioids in overdose deaths.

METHODS

Data from the census of deaths in the United States for 1999-2020 were used to understand trends in deaths involving gabapentinoids/Z-drugs and opioid co-involvement. These trends were studied overall and by sex, race, age, and education.

RESULTS

Per capita overdose deaths involving gabapentinoids/Z-drugs increased almost continuously since 1999, averaging 15.8% annual growth. This rate increased to 32% in 2020, primarily due to overdoses involving synthetic opioids. Women typically had higher rates of overdose deaths involving both opioids and gabapentinoids/Z-drugs, though this disparity disappeared in 2020. White Americans and American Indians/Alaskan Natives historically had higher rates than other racial groups; however, Black Americans experienced over 60% annual growth in recent years. Low education groups have been disproportionately impacted. The age incidence tends to be older than overdoses involving opioids more generally.

CONCLUSION

Overdose deaths involving opioids and gabapentinoids/Z-drugs have tended to disproportionately affect women and older age groups compared to all opioid-involved overdoses. As deaths involving synthetic opioids likely reflect use of illicitly-obtained opioids, there may be less of a role for policies targeting the concurrent prescribing of gabapentinoids/Z-drugs with opioids to reduce these deaths.

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.

Abuse/Misuse of Prescription Medications in Older Adults

The world population is aging due to increasing life expectancy. The rate of drug use increases, and inappropriate prescribing is frequently encountered with advancing age. In addition, misuse and abuse of prescription drugs is a serious problem in older adults. It is challenging to detect substance and drug abuse in older patients because it may have fewer consequences in social, legal, and occupational fields. However, there is not enough information about the screening, evaluation, diagnosis, and treatment of abuse. Therefore, the awareness of health care professionals and others involved in older patients' care should be raised about the misuse and abuse of drugs.

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.

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.