Gabapentin misuse, abuse and diversion: a systematic review

Prescribing pattern insights from a longitudinal study of older adult inpatients with polypharmacy and chronic non-cancer pain

BACKGROUND

The present study sought to determine the prevalence of chronic non-cancer pain (CNCP) among older adult inpatients with polypharmacy. It also aimed to analyse prescription patterns and assess the therapy adequacy and patient complexity for those with and without CNCP.

METHODS

This 4-year longitudinal study examined data from an exhaustive acute care hospital register on home-dwelling older adult patients (≥65) with polypharmacy. Commonly known combinations of potentially inappropriate medications were used to estimate therapy adequacy. Patient complexity was evaluated by comparing number of comorbidities and investigating physical and cognitive deficits.

RESULTS

We determined a prevalence of CNCP of 9.7% among all older adult inpatients with polypharmacy, rising to 11.3% for those aged ≥85. Overall, CNCP patients were prescribed more drugs and had more comorbidities and physical and cognitive deficits than patients without CNCP. Older adult patients with CNCP received more analgesics, greater quantities of opioids, paracetamol and co-analgesics and elevated opioid dosages. Older adult patients with CNCP aged ≥85 received fewer analgesics, opioids, non-steroidal anti-inflammatory drugs and co-analgesics but more paracetamol. Older adult patients with CNCP were prescribed more potentially inappropriate medications involving opioids. In particular, 24.5% received an opioid and a hypnotic (benzodiazepine or Z-drug), and 8.6% received an opioid and a gabapentinoid.

CONCLUSION

Observed differences in medication use between older adult inpatients with or without CNCP may be relevant for clinical practice. Potentially inadequate co-prescribing (such as hypnotics and opioids) affects a higher proportion of patients with CNCP and may have serious unintended consequences.

SIGNIFICANCE STATEMENT

This study describes differences in prescription patterns between people with and without chronic non-cancer pain in a large dataset of 20,422 discharges. The differences found may be relevant to clinical practice. In particular, high co-prescribing of opioids and hypnotics may have serious unintended consequences. Greater physical and cognitive deficits may indicate greater patient complexity, and appropriate interventions need to be developed to improve the management of this vulnerable patient group.

Association of Opioid Use Disorder Diagnosis with Management of Acute Low Back Pain: A Medicare Retrospective Cohort Analysis

BACKGROUND

Practice guidelines recommend nonpharmacologic and nonopioid therapies as first-line pain treatment for acute pain. However, little is known about their utilization generally and among individuals with opioid use disorder (OUD) for whom opioid and other pharmacologic therapies carry greater risk of harm.

OBJECTIVE

To determine the association between a pre-existing OUD diagnosis and treatment of acute low back pain (aLBP).

DESIGN

Retrospective cohort study using 2016-2019 Medicare data.

PARTICIPANTS

Fee-for-service Medicare beneficiaries with a new episode of aLBP.

MAIN MEASURES

The main independent variable was OUD diagnosis measured prior to the first LBP claim (i.e., index date). Using multivariable logistic regressions, we assessed the following outcomes measured within 30 days of the index date: (1) nonpharmacologic therapies (physical therapy and/or chiropractic care), and (2) prescription opioids. Among opioid recipients, we further assessed opioid dose and co-prescription of gabapentin. Analyses were conducted overall and stratified by receipt of physical therapy, chiropractic care, opioid fills, or gabapentin fills during the 6 months before the index date.

KEY RESULTS

We identified 1,263,188 beneficiaries with aLBP, of whom 3.0% had OUD. Two-thirds (65.8%) did not receive pain treatments of interest at baseline. Overall, nonpharmacologic therapy receipt was less prevalent and opioid and nonopioid pharmacologic therapies were more common among beneficiaries with OUD than those without OUD. Beneficiaries with OUD had lower odds of receiving nonpharmacologic therapies (aOR = 0.62, 99%CI = 0.58-0.65) and higher odds of prescription opioid receipt (aOR = 2.24, 99%CI = 2.17-2.32). OUD also was significantly associated with increased odds of opioid doses ≥ 90 morphine milligram equivalents/day (aOR = 2.43, 99%CI = 2.30-2.56) and co-prescription of gabapentin (aOR = 1.15, 99%CI = 1.09-1.22). Similar associations were observed in stratified groups though magnitudes differed.

CONCLUSIONS

Medicare beneficiaries with aLBP and OUD underutilized nonpharmacologic pain therapies and commonly received opioids at high doses and with gabapentin. Complementing the promulgation of practice guidelines with implementation science could improve the uptake of evidence-based nonpharmacologic therapies for aLBP.

GABAergic implications in anxiety and related disorders

Evidence indicates that anxiety disorders arise from an imbalance in the functioning of brain circuits that govern the modulation of emotional responses to possibly threatening stimuli. The circuits under consideration in this context include the amygdala's bottom-up activity, which signifies the existence of stimuli that may be seen as dangerous. Moreover, these circuits encompass top-down regulatory processes that originate in the prefrontal cortex, facilitating the communication of the emotional significance associated with the inputs. Diverse databases (e.g., Pubmed, ScienceDirect, Web of Science, Google Scholar) were searched for literature using a combination of different terms e.g., "anxiety", "stress", "neuroanatomy", and "neural circuits", etc. A decrease in GABAergic activity is present in both anxiety disorders and severe depression. Research on cerebral functional imaging in depressive individuals has shown reduced levels of GABA within the cortical regions. Additionally, animal studies demonstrated that a reduction in the expression of GABAA/B receptors results in a behavioral pattern resembling anxiety. The amygdala consists of inhibitory networks composed of GABAergic interneurons, responsible for modulating anxiety responses in both normal and pathological conditions. The GABAA receptor has allosteric sites (e.g., α/γ, γ/β, and α/β) which enable regulation of neuronal inhibition in the amygdala. These sites serve as molecular targets for anxiolytic medications such as benzodiazepine and barbiturates. Alterations in the levels of naturally occurring regulators of these allosteric sites, along with alterations to the composition of the GABAA receptor subunits, could potentially act as mechanisms via which the extent of neuronal inhibition is diminished in pathological anxiety disorders.

Sleep as an Important Target or Modifier in Alcohol Use Disorder Clinical Treatment: Example From a Recent Gabapentin Randomized Clinical Trial

OBJECTIVES

Alcohol consumption affects sleep both in healthy populations and in patients with alcohol use disorder (AUD). However, sleep has typically not been considered within AUD pharmacotherapy trials. We used data from a completed gabapentin clinical treatment trial to explore the medication's effect on patient-rated insomnia measured by a standard insomnia rating (Insomnia Severity Index [ISI]) and whether this influenced gabapentin's effects on alcohol consumption.

METHODS

This study included 90 individuals with current Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition AUD criteria reporting current or past alcohol withdrawal. Participants were assigned to placebo or gabapentin (up to 1200 mg/day) for a 16-week randomized controlled trial with percent heavy drinking days (PHDD) and percent abstinent days (PDA) as outcomes. Utilizing mixed-effects models, this study assessed medication effects on ISI over the trial. We then examined the interaction of baseline ISI and medication on drinking. Finally, given our previous finding of alcohol withdrawal influencing gabapentin efficacy, we added change in ISI as a potential "moderator" of the interaction of medication effects and alcohol withdrawal on drinking.

RESULTS

Sleep (ISI) improved more in those treated with gabapentin (60.6% reduction) compared with placebo (37.8% reduction; P = 0.013). Higher baseline ISI predicted drinking in gabapentin-treated individuals (lower PHDD [P = 0.026] and higher (PDA [P = 0.047]). ISI was an independent predictor of PHDD decrease and PDA increase (P < 0.001; P = 0.002), but this did not significantly moderate gabapentin's effectiveness.

CONCLUSIONS

Although gabapentin positively impacts both alcohol use and sleep, its effect on drinking is not fully dependent on sleep improvement, implying a direct biological mechanism on alcohol use.

Areas of interest and sentiment analysis towards second generation antipsychotics, lithium and mood stabilizing anticonvulsants: Unsupervised analysis using Twitter

BACKGROUND

Severe mental disorders like Schizophrenia and related psychotic disorders (SRD) or Bipolar Disorder (BD) require pharmacological treatment for relapse prevention and quality of life improvement. Yet, treatment adherence is a challenge, partly due to patients' attitudes and beliefs towards their medication. Social media listening offers insights into patient experiences and preferences, particularly in severe mental disorders.

METHODS

All tweets posted between 2008 and 2022 mentioning the names of the main drugs used in SRD and BD were analyzed using advanced artificial intelligence techniques such as machine learning, and deep learning, along with natural language processing.

RESULTS

In this 15-year study analyzing 893,289 tweets, second generation antipsychotics received more mentions in English tweets, whereas mood stabilizers received more tweets in Spanish. English tweets about economic and legal aspects displayed negative emotions, while Spanish tweets seeking advice showed surprise. Moreover, a recurring theme in Spanish tweets was the shortage of medications, evoking feelings of anger among users.

LIMITATIONS

This study's analysis of Twitter data, while insightful, may not fully capture the nuances of discussions due to the platform's brevity. Additionally, the wide therapeutic use of the studied drugs, complicates the isolation of disorder-specific discourse. Only English and Spanish tweets were examined, limiting the cultural breadth of the findings.

CONCLUSION

This study emphasizes the importance of social media research in understanding user perceptions of SRD and BD treatments. The results provide valuable insights for clinicians when considering how patients and the general public view and communicate about these treatments in the digital environment.

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.

Efficient and eco-friendly detection of gabapentin using nitrogen-doped carbon quantum dots: an analytical and green chemistry approach

This study presents the development of an eco-friendly and highly selective mitrogen-doped carbon quantum dot based sensor (N-CQDs) for the detection of gabapentin - a commonly misused drug. A detailed characterization of N-CQDs spectral features and their interaction with gabapentin is provided. The optimal conditions for sensing, including pH value, buffer volume, N-CQDs concentration, and incubation time, were established. The results showed excellent fluorescence quenching at 475 nm (λex = 380 nm) due to the dynamic quenching mechanism, and the sensor demonstrated excellent linearity in the 0.5-8.0 μg mL-1 concentration range with correlation coefficients of more than 0.999, a limit of detection (LOD) of 0.160 and limit of quantification (LOQ) of 0.480 μg mL-1. The accuracy of the proposed sensor was acceptable with a mean accuracy of 99.91 for gabapentin detection. In addition, precision values were within the acceptable range, with RSD% below 2% indicating good repeatability and reproducibility of the sensor. Selectivity was validated using common excipients and pooled plasma samples. The proposed sensor accurately estimated gabapentin concentration in commercial pharmaceutical formulations and spiked plasma samples, exhibiting excellent comparability with previously published methods. The 'greenness' of the sensing system was evaluated using the Analytical GREEnness calculator, revealing low environmental impact and strong alignment with green chemistry principles with a greenness score of 0.76. Thus, the developed N-CQDs-based sensor offers a promising, eco-friendly, and effective tool for gabapentin detection in various situations, ranging from clinical therapeutics to forensic science.

Electronic survey investigating UK veterinarians' perceptions of the potential for veterinary prescription medication misuse or abuse

OBJECTIVE

To investigate veterinarians' experience and perception of the risk of veterinary prescription medication (VPM) misuse and abuse by the public and veterinary professionals and to determine the clinical context in which respondent veterinarians prescribed certain VPMs.

STUDY DESIGN

Anonymous online voluntary survey.

POPULATION

A total of 361 of 7126 veterinarians registered as practicing in the UK, who provided e-mail contact details to the Royal College of Veterinary Surgeons Knowledge for participation in research. Respondents included general practitioners, with or without further qualifications, and European specialists, covering charity, private or academic small, large or mixed animal practice.

METHODS

The anonymous online survey, open from September to December 2021, posed 27 questions regarding personal experience and perception of VPM misuse or abuse, including which VPMs were considered most at risk of abuse by clients or veterinary staff. Thematic analysis was performed on free-text sections.

RESULTS

The participation rate was 5% (361/7126), and the completion rate 60% (216/361 respondents). Of these, 88% of respondents somewhat agreed, agreed or strongly agreed that some VPMs were at risk of abuse. A third (29.9%; 107/358) had suspected an owner of taking VPMs, and one fifth (20.1%; 72/358) had suspected veterinary staff. Perceptions regarding the likelihood of public VPM abuse ranged from not suspecting a problem to having first-hand experience. Drugs considered most at risk of owner abuse were opioids, benzodiazepines and gabapentin, and those for veterinary staff were opioids, benzodiazepines and ketamine. Numerous 'red flags' prompting suspicion of VPM abuse were identified alongside ways of mitigating risk.

CONCLUSIONS AND CLINICAL RELEVANCE

Veterinarians in the UK reported varied experiences with, awareness of, and attitudes towards VPM abuse by the public and veterinary staff. Although not quantified, the UK veterinary industry could be a source of abusable drugs.

Topical gabapentin solution for the management of burning mouth syndrome: A retrospective study

OBJECTIVE

The aim of this retrospective study was to evaluate the effectiveness and safety of topical gabapentin solution (250 mg/mL) for the management of burning mouth syndrome (BMS).

STUDY DESIGN

A retrospective chart review was conducted of all patients diagnosed with BMS and managed with gabapentin 250 mg/mL solution (swish and spit) between January 2021 and October 2022. Patient-reported outcomes included changes in burning score ranked on a 10-point numeric rating scale (NRS) and reported adverse drug reactions (ADR). Wilcoxon signed-rank test was used to assess differences in the oral burning score ranked on a NRS (0-10) between the baseline visit and the second visit.

RESULTS

A total of 19 patients (68.4% females) with BMS were included and evaluated for follow-up at a median of 86 days (range: 29-195). Overall, patients reported a median 2-point burning decrease on a 0-10 NRS between the baseline visit and the second visit (p < 0.01). ADRs were reported by 3 patients (15.8%).

CONCLUSION

Although this was a small retrospective study, BMS management with topical gabapentin (250 mg/mL) appears to be effective and well-tolerated. Future randomized prospective studies are needed to verify these preliminary findings.

Gabapentinoids in Ireland 2010 to 2020: An observational study of trends in gabapentinoid prescribing, law enforcement drug seizures and postmortem toxicology

AIMS

We explored trends in gabapentinoid prescribing, drug seizures and postmortem toxicology using a national pharmacy claims database, law enforcement drug seizures data and a population-based postmortem toxicology database.

METHODS

Gabapentinoid prescribing rates per 100 000 eligible population (2010-2020), annual number of drug seizures involving gabapentinoids (2012-2020) and gabapentinoid detection (positive) rates per 100 postmortem toxicology case (2013-2020) were calculated. Negative binomial regression models were used to evaluate longitudinal trends for gabapentin and pregabalin separately.

RESULTS

Gabapentin (adjusted rate ratio [RR] 1.06, 95% confidence interval [CI] 1.05-1.06, P < .001) and pregabalin (adjusted RR 1.08, 95% CI 1.08-1.09, P < .001) prescribing increased annually, with higher rates of pregabalin (vs. gabapentin) observed every year. Drug seizures involving pregabalin also increased over time (RR 1.54 95% CI 1.25-1.90, P < .0001). Of the 26 317 postmortem toxicology cases, 0.92% tested positive for gabapentin, and 6.37% for pregabalin. Detection rates increased for both gabapentin (RR 1.28, 95% CI 1.11-1.48, P < .001) and pregabalin (RR 1.13, 95% CI 1.11-1.48, P < .001) between 2013 and 2020. A total of 1901 cases (7.2%) tested positive for heroin/methadone; this sub-group had a higher detection rate for pregabalin (n = 528, 27.8%) and gabapentin (n = 41, 2.2%) over the study period, with a high burden of codetections for pregabalin with benzodiazepines (peaking at 37.3% in 2018), and pregabalin with prescription opioids (peaking at 28.9% in 2020).

CONCLUSION

This study raises concerns regarding the wide availability of pregabalin in Ireland, including a growing illicit supply, and the potential for serious harm arising from poly drug use involving pregabalin among people who use heroin or methadone.

Gabapentin Use Among Individuals Initiating Buprenorphine Treatment for Opioid Use Disorder

Importance

Gabapentin prescriptions have drastically increased in the US due to off-label prescribing in settings such as opioid use disorder (OUD) treatment to manage a range of comorbid conditions and withdrawal symptoms, despite a lack of evidence.

Objective

To assess the purpose and associated risks of off-label gabapentin use in OUD treatment.

Design, Setting, and Participants

This retrospective recurrent-event case-control study with a crossover design used administrative claims data from MarketScan Commercial and Multi-State Medicaid databases from January 1, 2006, to December 31, 2016. Individuals aged 12 to 64 years with an OUD diagnosis and filling buprenorphine prescriptions were included in the primary analysis conducted from July 1, 2022, through June 1, 2023. Unit of observation was the person-day.

Exposures

Days covered by filled gabapentin prescriptions.

Main Outcomes and Measures

Primary outcomes were receipt of gabapentin in the 90 days after initiation of buprenorphine treatment and drug-related poisoning. Drug-related poisonings were defined using codes from International Classification of Diseases, Ninth Revision, and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision.

Results

A total of 109 407 patients were included in the analysis (mean [SD] age, 34.0 [11.2] years; 60 112 [54.9%] male). Among the 29 967 patients with Medicaid coverage, 299 (1.0%) were Hispanic, 1330 (4.4%) were non-Hispanic Black, 23 112 (77.1%) were non-Hispanic White, and 3399 (11.3%) were other. Gabapentin was significantly less likely to be prescribed to Black or Hispanic patients, and more likely to be prescribed to female patients, those with co-occurring substance use or mood disorders, and those with comorbid physical conditions such as neuropathic pain. Nearly one-third of persons who received gabapentin (4336 [31.1%]) had at least 1 drug-related poisoning after initiating buprenorphine treatment, compared with 13 856 (14.5%) among persons who did not receive gabapentin. Adjusted analyses showed that days of gabapentin use were not associated with hospitalization for drug-related poisoning (odds ratio, 0.98 [95% CI, 0.85-1.13]). Drug-related poisoning risks did not vary based on dosage.

Conclusions and Relevance

Gabapentin is prescribed in the context of a myriad of comorbid conditions. Even though persons receiving gabapentin are more likely to have admissions for drug-related poisoning, these data suggest that gabapentin is not associated with an increased risk of drug-related poisoning alongside buprenorphine in adjusted analyses. More data on the safety profile of gabapentin in OUD settings are needed.

Alcohol use disorder in the perioperative period: a summary and recommendations for anesthesiologists and pain physicians

Excessive alcohol consumption and alcohol use disorder (AUD) increase the risk of perioperative morbidity and mortality. Aspiration, malnutrition, coagulopathies, seizures, and hemodynamic alterations are only a few of the major concerns related to acute alcohol intoxication and AUD. There are also numerous physiological effects, changes in medication metabolism and pharmacology, and adverse events related to chronic alcohol consumption. These are all important considerations for the anesthesiologist in the perioperative management of a patient with AUD. Pain perception and thresholds are altered in patients with acute and chronic alcohol use. Medications used to manage AUD symptoms, particularly naltrexone, can have significant perioperative implications. Patients on naltrexone who continue or stop this medication in the perioperative period are at an increased risk for undertreated pain or substance use relapse. This review highlights key considerations for the anesthesiologist and pain physician in the perioperative management of patients with active AUD (or those in recovery). It discusses the effects of acute and chronic alcohol use on pain perception and thresholds, provides guidance on the perioperative management of naltrexone and low-dose naltrexone, and reviews a multimodal approach to pain management.

Effects of Acute and Chronic Gabapentin Treatment on Cardiovascular Function of Rats

Gabapentin (GBP), a GABA analogue, is primarily used as an anticonvulsant for the treatment of partial seizures and neuropathic pain. Whereas a majority of the side effects are associated with the nervous system, emerging evidence suggests there is a high risk of heart diseases in patients taking GBP. In the present study, we first used a preclinical model of rats to investigate, firstly, the acute cardiovascular responses to GBP (bolus i.v. injection, 50 mg/kg) and secondly the effects of chronic GBP treatment (i.p. 100 mg/kg/day × 7 days) on cardiovascular function and the myocardial proteome. Under isoflurane anesthesia, rat blood pressure (BP), heart rate (HR), and left ventricular (LV) hemodynamics were measured using Millar pressure transducers. The LV myocardium and brain cortex were analyzed by proteomics, bioinformatics, and western blot to explore the molecular mechanisms underlying GBP-induced cardiac dysfunction. In the first experiment, we found that i.v. GBP significantly decreased BP, HR, maximal LV pressure, and maximal and minimal dP/dt, whereas it increased IRP-AdP/dt, Tau, systolic, diastolic, and cycle durations (* p < 0.05 and ** p < 0.01 vs. baseline; n = 4). In the second experiment, we found that chronic GBP treatment resulted in hypotension, bradycardia, and LV systolic dysfunction, with no change in plasma norepinephrine. In the myocardium, we identified 109 differentially expressed proteins involved in calcium pathways, cholesterol metabolism, and galactose metabolism. Notably, we found that calmodulin, a key protein of intracellular calcium signaling, was significantly upregulated by GBP in the heart but not in the brain. In summary, we found that acute and chronic GBP treatments suppressed cardiovascular function in rats, which is attributed to abnormal calcium signaling in cardiomyocytes. These data reveal a novel side effect of GBP independent of the nervous system, providing important translational evidence to suggest that GBP can evoke adverse cardiovascular events by depression of myocardial function.

Concurrent Gabapentin and Opioid Use and Risk of Mortality in Medicare Recipients with Non-Cancer Pain

Gabapentin is prescribed for pain and is perceived as safe generally. However, gabapentin can cause respiratory depression, exacerbated by concomitant central nervous system depressants (e.g., opioids), a concern for vulnerable populations. We compared mortality rates among new users of either gabapentin or duloxetine with or without concurrent opioids in the 20% Medicare sample. We conducted a new-user design retrospective cohort study, in Medicare enrollees ages 65-89 years with noncancer chronic pain and no severe illness who filled prescriptions between 2015 and 2018 for gabapentin (n = 233,060) or duloxetine (n = 34,009). Daily opioid doses, estimated in morphine milligram equivalents (MMEs), were classified into none, low (0 < MME < 50), and high (≥ 50 MME), based on Centers for Disease Control and Prevention (CDC) recommendations. The outcomes were all-cause mortality (primary) and out-of-hospital mortality (secondary). We used inverse probability of treatment weighting to adjust for differences between gabapentin and duloxetine users. During 116,707 person-years of follow-up, 1,379 patients died. All-cause mortality rate in gabapentin users was 12.16 per 1,000 person-years vs. 9.94 per 1,000 in duloxetine users. Risks were similar for users with no concurrent opioids (adjusted hazard ratio (aHR) = 1.03, 95% confidence interval (CI): 0.80-1.31) or low-dose daily opioids (aHR = 1.06, 95% CI: 0.63-1.76). However, gabapentin users receiving concurrent high-dose daily opioids had an increased rate of all-cause mortality compared with duloxetine users on high-dose opioids (aHR = 2.03, 95% CI: 1.19-3.46). Out-of-hospital mortality yielded similar results. In this retrospective cohort study of Medicare beneficiaries, concurrent use of high-dose opioids and gabapentin was associated with a higher all-cause mortality risk than that for concurrent use of high-dose opioids and duloxetine.

Prescription drugs with potential for misuse in Irish prisons: analysis of national prison prescribing trends, by gender and history of opioid use disorder, 2012 to 2020

BACKGROUND

Pharmacotherapy is essential for the delivery of an equivalent standard of care in prison. Prescribing can be challenging due to the complex health needs of prisoners and the risk of misuse of prescription drugs. This study examines prescribing trends for drugs with potential for misuse (opioids, benzodiazepines, Z-drugs, and gabapentinoids) in Irish prisons and whether trends vary by gender and history of opioid use disorder (OUD).

METHODS

A repeated cross-sectional study between 2012 and 2020 using electronic prescribing records from the Irish Prison Services, covering all prisons in the Republic of Ireland was carried out. Prescribing rates per 1,000 prison population were calculated. Negative binomial (presenting adjusted rate ratios (ARR) per year and 95% confidence intervals) and joinpoint regressions were used to estimate time trends adjusting for gender, and for gender specific analyses of prescribing trends over time by history of OUD.

RESULTS

A total of 10,371 individuals were prescribed opioid agonist treatment (OAT), opioids, benzodiazepines, Z-drugs or gabapentinoids during study period. History of OUD was higher in women, with a median rate of 597 per 1,000 female prisoners, compared to 161 per 1,000 male prisoners. Prescribing time trends, adjusted for gender, showed prescribing rates decreased over time for prescription opioids (ARR 0.82, 95% CI 0.80-0.85), benzodiazepines (ARR 0.99, 95% CI 0.98-0.999), Z-drugs (ARR 0.90, 95% CI 0.88-0.92), but increased for gabapentinoids (ARR 1.07, 95% CI 1.05-1.08). However, prescribing rates declined for each drug class between 2019 and 2020. Women were significantly more likely to be prescribed benzodiazepines, Z-drugs and gabapentinoids relative to men. Gender-specific analyses found that men with OUD, relative to men without, were more likely to be prescribed benzodiazepines (ARR 1.49, 95% CI 1.41-1.58), Z-drugs (ARR 10.09, 95% CI 9.0-11.31), gabapentinoids (ARR 2.81, 95% CI 2.66-2.97). For women, history of OUD was associated with reduced gabapentinoid prescribing (ARR 0.33, 95% CI 0.28-0.39).

CONCLUSIONS

While the observed reductions in prescription opioid, benzodiazepine and Z-drug prescribing is consistent with guidance for safe prescribing in prisons, the increase in gabapentinoid (primarily pregabalin) prescribing and the high level of prescribing to women is concerning. Our findings suggest targeted interventions may be needed to address prescribing in women, and men with a history of OUD.

An enhanced recovery after surgery protocol for facial feminization surgery reduces perioperative opioid usage, pain, and hospital stay

BACKGROUND

Prescription drug misuse in transgender individuals is estimated to be three times higher than that of the general population in the United States, suggesting that opioid-reduction strategies deserve significant consideration in gender-affirming surgeries. In this work, we describe the implementation of an enhanced recovery after surgery (ERAS) protocol to reduce opioid use after facial feminization surgery.

METHODS

A total of 79 patients who underwent single-stage facial feminization surgery before (n = 38) or after (n = 41) ERAS protocol implementation were included. Primary outcomes assessed were perioperative opioid consumption (morphine equivalent dose/kilogram, MED/kg), average patient-reported pain scores, and length of hospital stay. Comparisons between groups and multivariable linear regression analyses were conducted to define the contribution of the ERAS protocol to each of the three primary outcomes.

RESULTS

Age, body mass index, mental health diagnoses, and length of surgery did not differ between pre-ERAS and ERAS groups. Compared to pre-ERAS patients, patients treated under the ERAS protocol consumed less opioids (median [interquartile range, IQR], 0.8 [0.5-1.1] versus 1.5 [1.0-2.1] MED/kg, p < 0.001), reported lower pain scores (2.5 ± 1.8 versus 3.7 ± 1.6, p = 0.002), and required a shorter hospital stay (median [IQR], 27.3 [26.3-49.8] versus 32.4 [24.8-39.1] h, p < 0.001). When controlling for other contributing variables such as previous gender-affirming surgeries, mental health diagnoses, and length of surgery using multivariable linear regression analyses, ERAS protocol implementation independently predicted reduced opioid use, lower pain scores, and shorter hospital stay after facial feminization surgery.

CONCLUSIONS

The current work details an ERAS protocol for facial feminization surgery that reduces perioperative opioid consumption, patient-reported pain scores, and hospital stays.

Incident mental health episodes after initiation of gabapentinoids vs. dopamine agonists for early-onset idiopathic restless legs syndrome

Limited long-term safety information exists for gabapentinoid treatment of idiopathic restless legs syndrome (RLS). We estimated incident mental health-related emergency department visits and hospitalizations with a primary mental health diagnosis (primary outcome) among early-onset idiopathic RLS patients following first-line treatment initiation and examined outcome risk with gabapentinoids compared with dopamine agonists (DAs). A retrospective cohort study was conducted using administrative claims data from 2012 to 2019. Adults with early-onset (18-44 years) idiopathic RLS initiating either gabapentinoids or DAs within 60 days of new diagnosis were followed up to two years. Incidence rates were calculated and a log-binomial regression model with propensity score weighting estimated relative risk of the outcome and of substance use disorders (SUDs) as a secondary analysis with gabapentinoids. Among a cohort of 6,672 patients, 4,986 (74.7%) initiated DAs and 1,686 (25.3%) gabapentinoids. Incidence of the primary outcome (49.8 [95% CI 40.8-69.3] per 1,000 person-years) and SUDs (49.5 [95% CI 40.6-59.9] per 1,000 person-years) were higher in the gabapentinoid group compared with the DA group. A statistically significant risk of mental health diagnoses with gabapentinoids was not detected, but SUD risk was significant after covariate adjustment. High-risk mental health comorbidities (i.e., SUDs) should be considered when initiating RLS treatments.

Gabapentin and Opioids Utilization in Patients With Diabetic Neuropathy Enrolled in Medicare (2012-2016): A Cohort Study

This retrospective cohort study describes the utilization of opioids and gabapentin among patients with diabetic neuropathy who were gabapentin and opioid naïve, and assesses predictors of concomitant use of opioids and gabapentin. Using Medicare claims data (2012-2016), 22 037 patients were identified, of whom 23.42% (N = 5161) initiated opioids without concomitant gabapentin, 4.56% (N = 1004) initiated gabapentin without concomitant opioids, and 3.87% (N = 852) had concomitant use of gabapentin and opioids 12 months following their index date (date of earliest diagnosis). Concomitant gabapentin and opioid use were more common for lower doses of both drugs and for 15 days or more cumulatively. Compared to individuals aged 65-74, those aged 75-84 (OR: .759; 95% CI: 0.653-.882) or ≥ 85 years (OR: .586, 95% CI: 0.462-.743) had lower odds of concomitant use. People residing in the Northeast had lower odds of concomitant use, compared to those residing in the South (OR: .646 95% CI: 0.535-.779). Females compared to males (OR: 1.185, 95% CI: 1.027-1.367), people with higher Charlson's Comorbidity Index (CCI) scores (OR: 1.085, 95% CI: 1.037-1.135) or those having anxiety (OR: 1.462, 95% CI: 1.131-1.889) had higher odds of concomitant use. Concomitant prescriptions of opioids and gabapentin were more common for longer durations, indicating the need for interventions aimed at minimizing this prescribing practice.

Experiences of misuse and symptoms of dependence among people who use gabapentinoids: a qualitative systematic review protocol

INTRODUCTION

Gabapentinoids are among the most widely prescribed pain medications. However, there is growing evidence to suggest that gabapentinoids may be associated with dependence and misuse. The aim of this systematic review is to synthesise the qualitative literature on gabapentinoid misuse and symptoms of dependence. The findings of this study will inform efforts to mitigate emerging harms.

METHODS AND ANALYSIS

A systematic review of qualitative research will explore lived experiences of misuse and symptoms of dependence among people who use gabapentinoids. Six databases (MEDLINE, Scopus, Web of Science, CINAHL, EMBASE and PsycINFO) and grey literature sources will be searched from inception to May 2023. Qualitative studies that include people with lived experiences of gabapentinoid misuse and symptoms of gabapentinoid dependence will be included. Reference lists of included studies will also be screened for additional studies. The methodological quality of included studies will be appraised using the Critical Appraisal Skills Programme qualitative checklist, and higher quality studies will be prioritised in the thematic synthesis. The GRADE-CERQual approach will be used to assess confidence in the overall findings of the review.

ETHICS AND DISSEMINATION

Ethical approval is not required for this systematic review. The findings of this review will be disseminated in peer-reviewed journals, at conferences and on social media.

PROSPERO REGISTRATION NUMBER

CRD42023401832.

Patterns of Cough Medication Prescribing among Patients with Chronic Cough in Florida: 2012-2021

Among patients with chronic cough (CC) in the 2012-2021 statewide OneFlorida Clinical Research Consortium database, we examined trends in cough medication (CM) prescribing prevalence over time in repeated cross-sectional analyses and identified distinct CM utilization trajectories using group-based trajectory modeling (GBTM) in a retrospective cohort study. Among eligible adults (≥18 years) without cancer/benign respiratory tumor diagnoses, we identified CC patients and non-CC patients with any cough-related diagnosis. In the GBTM analysis, we calculated the number of monthly prescriptions for any CMs (excluding gabapentinoids) during the 12 months from the first qualifying cough event to identify distinct utilization trajectories. From 2012 to 2021, benzonatate (9.6% to 26.1%), dextromethorphan (5.2% to 8.6%), and gabapentinoid (5.3% to 14.4%) use increased among CC patients, while opioid antitussive use increased from 2012 to 2015 and decreased thereafter (8.4% in 2012, 14.7% in 2015, 6.7% in 2021; all p < 0.001). Of 15,566 CC patients and 655,250 non-CC patients identified in the GBTM analysis, CC patients had substantial burdens of respiratory/non-respiratory comorbidities and healthcare service and concomitant medication use compared to non-CC patients. Among CC patients, GBTM identified three distinct CM utilization trajectories: (1) no CM use (n = 11,222; 72.1%); (2) declining CM use (n = 4105; 26.4%); and (3) chronic CM use (n = 239; 1.5%). CC patients in Florida had limited CM use with increasing trends in use of benzonatate, dextromethorphan, and gabapentinoids and a decreasing trend in opioid antitussive use. CC patients, particularly with chronic prescription CM use, experienced substantial disease burden.

Negative experiences of patients using medicinal cannabis: A systematic review of qualitative studies

AIMS AND OBJECTIVES

In this study, we systematically reviewed qualitative studies concerning patients' experience with medicinal cannabis (MC) use, to gain insight into the negative effects of MC.

BACKGROUND

Over the past decades, the use of MC for therapeutic purposes has increased. However, there is conflicting and insufficient data on possible negative physiological and psychological effects of MC treatment.

DESIGN

A systematic review was conducted and the PRISMA guidelines were adopted. Literature searches were conducted using PubMed, PsycINFO and EMBASE. Critical Appraisal Skills Programme (CASP) qualitative checklist used to assess risk of bias in the included studies.

METHODS

We included studies focusing on conventional medical treatment using cannabis-based products, approved by a physician for a particular health issue.

RESULTS

Of the 1230 articles identified in the initial search, eight articles were included in the review. Following the compilation of themes in the eligible studies, six themes were identified: (1) MC approval; (2) administrative barriers; (3) social perception; (4) MC misuse/widespread effect; (5) adverse effects; and (6) dependence or addiction. These were grouped into two meta-themes: (1) administrative and social aspects of MC use; and (2) experiences of the effects of medicinal cannabis.

CONCLUSIONS

Our findings call for specific attention to unique consequences associated with MC use. Further research is needed in order to assess the degree to which negative experiences associated with MC use may affect various aspects of patients' medical condition.

RELEVANCE TO CLINICAL PRACTICE

Describing the complex experience of MC treatment and its spectrum of consequences for patients may enable physicians, therapists and researchers to provide more attentive and accurate MC treatment to their patients.

PATIENT OR PUBLIC CONTRIBUTION

In this review, patients' narratives were explored, yet the research methods did not directly involve patients or the public.

Medication treatment for alcohol use disorder in special populations

BACKGROUND AND OBJECTIVES

Alcohol use disorder (AUD) is a significant public health concern, with underutilized effective treatments, particularly in special populations. This article summarizes the current evidence and guidelines for treating AUD in special populations.

METHODS

This article is a literature review that synthesizes the latest research on AUD treatment for special populations. We screened 242 articles and included 57 in our final review.

RESULTS

There are four food and Drug Administration-approved medications for AUD (MAUD): disulfiram, oral naltrexone, extended-release injectable naltrexone (XR-NTX), and acamprosate. Naltrexone and disulfiram have the potential to cause liver toxicity, and acamprosate should be avoided in patients with severe kidney disease. Psychosocial treatments should be considered first-line for pregnant and nursing patients. Naltrexone is contraindicated in patients on opioids, as it may precipitate acute withdrawal. For patients experiencing homelessness, nonabstinent treatment goals may be more practical, and XR-NTX should be considered to improve adherence. Limited evidence suggests medication can improve AUD treatment outcomes in adolescents and young adults. For patients with poor treatment response despite adequate medication adherence, switching to a different medication and augmentation with psychosocial treatments should be considered.

DISCUSSION AND CONCLUSIONS

Understanding the unique considerations for special populations with AUD is crucial, and addressing their special needs may improve their treatment outcomes.

SCIENTIFIC SIGNIFICANCE

Our study significantly contributes to the existing literature by summarizing crucial information for the treatment of AUD in special populations, highlighting distinct challenges, and emphasizing tailored approaches to improve overall health and well-being.

Misuse of gabapentinoids (pregabalin and gabapentin) in patients with neuropathic pain related to spinal cord injury

OBJECTIVE

To investigate the misuse of gabapentinoids (pregabalin and gabapentin) in patients with neuropathic pain related to spinal cord injury.

STUDY DESIGN

Cross-sectional study.

SETTING

Outpatient clinic in a physical therapy and rehabilitation hospital.

PARTICIPANTS

127 patients, aged 18-70 years, who had neuropathic pain related to spinal cord injury (SCI) and disease duration of at least 12 months.

OUTCOME MEASURES

Gabapentinoid use disorder of the patients was determined based on the DSM-5 diagnostic criteria for substance-related disorders. Patients were divided into 2 groups as those with drug misuse and those without drug misuse. Demographic and clinical information of the patients were compared between the groups. Factors associated with drug misuse were analyzed.

RESULTS

The misuse rate was 81.9% in patients using pregabalin and 69.69% in patients using gabapentin. Duration of disease and the Leeds assessment of neuropathic symptoms and signs (LANSS) score were statistically significantly higher in the drug misuse group. A statistically significant difference was found between the groups in terms of marital status, education and income level, and smoking and alcohol use. A statistically significant relationship was observed between drug misuse and duration of disease and LANSS score.

CONCLUSION

Misuse of gabapentinoids is prevalent in patients with neuropathic pain related to spinal cord injury. The duration of disease and the severity of NP are associated with misuse. Clinicians should exercise caution when prescribing gabapentinoids to patients with SCI.

Understanding the rise in overdose deaths involving opioids and non-opioid prescription drugs in the United States

BACKGROUND

Previous studies demonstrate that the reformulation of OxyContin in the U.S. in 2010 induced substitution to illicit opioids, causing illicit opioid markets to grow disproportionately fast in states more exposed to the reformulation. In this paper, we examine if this shift to the illicit market also led to a rise in polysubstance overdose deaths involving non-opioid prescription drugs, including gabapentinoids and "Z-drugs" and, separately, benzodiazepines.

METHODS

Using a difference-in-differences framework, the relationship between exposure to reformulation and overdose death rates including specific substances was studied in each year from 1999 to 2020 while accounting for fixed differences across states, common nationwide shocks, and state-level differences in pain reliever misuse prior to reformulation. Exposure to reformulation was measured as the pre-reformulation rate of OxyContin misuse.

RESULTS

Exposure to reformulation predicted growth in overdose deaths involving gabapentinoids and Z-drugs. There is less evidence that it predicted growth in overdose deaths involving benzodiazepines. However, for all substances, there is strong evidence that pre-reformulation OxyContin misuse rates predicted post-reformulation growth in overdose deaths concurrently involving synthetic opioids.

DISCUSSION

The opioid crisis has changed in radical ways. This study links a major supply-side intervention to the increase in polysubstance overdose deaths involving non-opioid prescription drugs, specifically gabapentinoids and Z-drugs.

Medications for treating alcohol use disorder: A narrative review

Chronic heavy alcohol use impacts all major neurotransmitter systems and is associated with multiple medical, psychiatric, and social problems. Available evidence-based medications to treat alcohol use disorder (AUD) are underutilized in clinical practice. These medications promote abstinence or reduce alcohol consumption, though there are questions regarding their optimal dosage, length of treatment, and utility in combination with one another. Pharmacogenetic approaches, which use a patient's genetic make-up to inform medication selection, have garnered great interest but have yet to yield results robust enough to incorporate them in routine clinical care. This narrative review summarizes the evidence both for medications approved by the Food and Drug Administration (disulfiram, oral naltrexone, acamprosate, and extended-release naltrexone) and those commonly used off-label (e.g., gabapentin, baclofen, and topiramate) for AUD treatment. We discuss these drugs' mechanisms of action, clinical use, pharmacogenetic findings, and treatment recommendations. We conclude that the most consistent evidence supporting the pharmacotherapy of AUD is for the opioid antagonists, naltrexone and nalmefene (which is not approved in the United States), and topiramate. These medications demonstrate consistent small or moderate effects in reducing the frequency of drinking and/or heavy drinking. Lastly, we make suggestions for research needed to refine and expand the current literature on effective pharmacotherapy for AUD.

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.

The association between Gabapentin or Pregabalin use and the risk of dementia: an analysis of the National Health Insurance Research Database in Taiwan

Objective: Previous studies have shown that gabapentin or pregabalin use is associated with cognitive decline. Herein, we aimed to evaluate the association between gabapentin or pregabalin use and the risk of dementia. Methods: In this retrospective, population-based matched cohort study, all research data were collected from the 2005 Longitudinal Health Insurance Database, which contains data of 2 million people randomly selected from the National Health Insurance Research Database of Taiwan in 2005. The study extracted data from 1 January 2000, to 31 December 2017. Adult patients taking gabapentin or pregabalin were included in the exposure group, and patients not using gabapentin or pregabalin matched to exposure subjects in a 1:5 ratio by propensity scores composed of age, sex and index date were included in the non-exposure group. Results: A total of 206,802 patients were enrolled in the study. Of them, 34,467 gabapentin- or pregabalin-exposure and 172,335 non-exposure patients were used for analysis. The mean follow-up day (±standard deviation) after the index date was 1724.76 (±1282.32) and 1881.45 (±1303.69) in the exposure and non-exposure groups, respectively; the incidence rates of dementia were 980.60 and 605.48 per 100,000 person-years, respectively. The multivariate-adjusted hazard ratio of risk of dementia for gabapentin or pregabalin exposure versus the matched non-exposed group was 1.45 (95% confidence interval [CI], 1.36-1.55). The risk of dementia increased with higher cumulative defined daily doses during the follow-up period. Moreover, the stratification analysis revealed that the risk of dementia associated with gabapentin or pregabalin exposure was significant in all age subgroups; however, it was higher in younger patients (age <50) than in the older patients (hazard ratio, 3.16; 95% CI, 2.23-4.47). Conclusion: Patients treated with gabapentin or pregabalin had an increased risk of dementia. Therefore, these drugs should be used with caution, particularly in susceptible individuals.

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.

[Pregabalin under the prison lens. Reflections on an emerging issue]

The practice of medicine in prison confronts the prescriber with emerging trends in psychotropic drug misuse. We examine the increasing demand for pregabaliun, as we observe it in patients in detention, and offer a reflection on the health issues. We explain our approach to abstaining from prescribing.

The safety and efficacy of gabapentinoids in the management of neuropathic pain: a systematic review with meta-analysis of randomised controlled trials

BACKGROUND

There are increasing concerns regarding the abusive potential of gabapentinoids putting at risk patients with neuropathic pain requiring long-term pain management. The evidence to support this is rather inconcusive.

AIM

This systematic review aimed to evaluate the safety and efficacy of gabapentinoids in the management of neuropathic pain with a focus on randomised controlled trials (RCTs) and categorising the side effects according to the body systems they were affecting.

METHOD

Searches were conducted in MEDLINE (PubMed), EMBASE, Web of Science, PsycoINFO, and CINAHL (EBSCO), and included RCTs to identify and critically appraise studies investigating safety and therapeutic effects of gabapentionoids in adults with neuropathic pain. Data extraction was conducted using an established Cochrane form and the risk-of-bias tool was used in the assessment of quality.

RESULTS

50 studies (12,398 participants) were included. The majority of adverse events pertained to the nervous system (7 effects) or psychiatric (3 effects) disorders. There were more adverse effects reported with pregabalin (36 effects) than with gabapentin (22 effects). Six pregabalin studies reported euphoria as a side effect, while no studies reported euphoria with gabapentin. This was the only side effect that may correlate with addictive potential. Gabapentioids were reported to significantly reduce pain compared to placebo.

CONCLUSION

Despite RCTs documenting the adverse events of gabapentionoids on the nervous system, there was no evidence of gabapentinoid use leading to addiction, suggesting an urgent need to design studies investigating their abusive potential.

Application of gabapentinoids and novel compounds for the treatment of benzodiazepine dependence: the glutamatergic model

BACKGROUND

Current approaches for managing benzodiazepine (BZD) withdrawal symptoms are daunting for clinicians and patients, warranting novel treatment and management strategies. This review discusses the pharmacodynamic properties of BZDs, gabapentinoids (GBPs), endozepines, and novel GABAergic compounds associated with potential clinical benefits for BZD-dependent patients. The objective of this study was to review the complex neuromolecular changes occurring within the GABAergic and glutamatergic systems during the BZD tolerance and withdrawal periods while also examining the mechanism by which GBPs and alternative pharmacological therapies may attenuate withdrawal symptoms.

METHODS AND RESULTS

An elaborative literature review was conducted using multiple platforms, including the National Center for Biotechnology (NCBI), AccessMedicine, ScienceDirect, pharmacology textbooks, clinical trial data, case reports, and PubChem. Our literature analysis revealed that many distinctive neuroadaptive mechanisms are involved in the GABAergic and glutamatergic systems during BZD tolerance and withdrawal. Based on this data, we hypothesize that GBPs may attenuate the overactive glutamatergic system during the withdrawal phase by an indirect presynaptic glutamatergic mechanism dependent on the α₂δ₁ subunit expression.

CONCLUSIONS

GBPs may benefit individuals undergoing BZD withdrawal, given that the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor current significantly increases during abrupt BZD withdrawal in animal studies. This may be a conceivable explanation for the effectiveness of GBPs in treating both alcohol withdrawal symptoms and BZD withdrawal symptoms in some recent studies. Finally, natural and synthetic GABAergic compounds with unique pharmacodynamic properties were found to exert potential clinical benefits as BZD substitutes in animal studies, though human studies are lacking.

A Meta-analysis of Randomized Controlled Trials Comparing the Efficacy and Safety of Pregabalin and Gabapentin in the Treatment of Postherpetic Neuralgia

OBJECTIVE

To systematically evaluate the clinical efficacy of pregabalin and gabapentin in the treatment of postherpetic neuralgia (PHN), including the difference in pain control and occurrence of adverse reactions.

METHODS

PubMed, MEDLINE, EMBASE, Cochrane Library, and Web of Science databases were searched for randomized controlled trials (RCTs) comparing the efficacy of pregabalin and gabapentin in patients with PHN. Data from studies meeting the inclusion criteria were extracted and the Cochrane Risk of Bias risk assessment tool was used to evaluate the quality of the included studies. Revman 5.3 and Stata17 were used to perform the meta-analysis and to detect publication bias.

RESULTS

A total of 14 RCTs with 3545 patients were included in this study, including 926 in the pregabalin treatment group, 1256 in the gabapentin treatment group, and 1363 in the placebo control group. Pregabalin was better than gabapentin in alleviating pain and improving the global perception of change in pain and sleep (P < 0.05). Gabapentin was associated with a lower incidence of adverse events than pregabalin (P < 0.05). Funnel plot and Begg's and Egger's tests showed no significant publication bias.

CONCLUSION

Pregabalin appears to have a better overall therapeutic effect than gabapentin for patients with PHN, but gabapentin has a lower incidence of adverse reactions and a better safety profile. Clinicians should comprehensively consider patient factors and fully evaluate the advantages and disadvantages of each treatment option to select the most suitable drugs for patient use. Considering the limited quantity and quality of the existing literature, high-quality RCTs are needed to confirm the advantages of pregabalin over gabapentin in the treatment of PHN and guide clinical decision-making.

The Impact of Epilepsy on Complication Rates After Total Joint Arthroplasty: A Propensity Score-Matched Cohort Study

BACKGROUND

It is unclear how epilepsy may affect total joint arthroplasty outcomes. The purpose of this study is to analyze the impact of epilepsy on prosthesis-related complications following primary total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

A retrospective cohort study was conducted using a national database. Patients who have epilepsy underwent a primary THA (n = 6,981) and TKA (n = 4,987) and were matched 1:4 (THA, n = 27,924; TKA, n = 19,948). Rates of low-energy falls and prosthesis-related complications within 2 years postoperatively were compared for patients who did and did not have epilepsy with multivariable logistic regression.

RESULTS

After primary TKA, patients who have epilepsy exhibited significantly higher rates of aseptic revision (4.3% versus 3.5%, odds ratio [OR] 1.21, P = .017) and revision for prosthetic joint infection (1.8% versus 1.3%, OR 1.29, P = .041). THA patients who have epilepsy exhibited significantly higher rates of prosthetic dislocation (3.2% versus 1.9%, OR 1.54, P < .001), periprosthetic fracture (2.2% versus 0.8%, OR 2.39, P < .001), and aseptic loosening (1.7% versus 1.1%, OR 1.40, P = .002). Rates of low-energy falls within 2 years after TKA (14.1% versus 6.4%, OR 2.19, P < .001) and THA (33.6% versus 7.5%, OR 5.95, P < .001) were also significantly higher for patients who have epilepsy.

CONCLUSION

Epilepsy was associated with significantly higher rates of falls (P < .001) and prosthesis-related complications after primary THA (P < .05) and TKA (P < .05). Precautions should be implemented in this population during intraoperative and perioperative decision-making to reduce complication risk.

LEVEL OF EVIDENCE

Level III.

The Role of Gabapentinoids in the Substance Use Pattern of Adult Germans Seeking Inpatient Detoxification Treatment - A Pilot Study

To shed more light on the addictive power of the gabapentinoids (GPTs) gabapentin and pregabalin, we performed a structured face-to-face interview with GPT-users about DSM-IV-dependence-criteria (sedatives), consume-motives and cessation-needs. Among 100 patients consecutively admitted to a detoxification-ward, fifteen (15%) reported lifetime GPT-use (18-50 years old, 2 females): seven (7%) used gabapentin, twelve (12%) pregabalin and four had lifetime experiences with both GPTs. Of the seven gabapentin-users, three patients were dependent including one person with a spontaneous remission. Of the 12 pregabalin-users, five were dependent, including two persons with a spontaneous remission. Fourteen of fifteen cases reported GPT-use side-by-side with an opioid-use, mostly for sparing opioids. Twelve GPT-users additionally co-used benzodiazepines. In no case, a GPT was the reason for detoxification treatment or reported to be involved in an emergency event. Altogether, every 7^th patient (n = 15) of our inpatient detoxification-seeking sample reported GPT-use including 50% (n = 8) who were dependent. Among them, 35% (3/8) had been already spontaneously remitted. As GPT-users reported no cession-need and the vast majority were primarily affected by co-occurring opioid- and benzodiazepine-addiction, we assume that GPTs more likely played a bystander-role than mediating the addictive behavior of this population with multiple recreational drug use experience.

Gabapentin, Concomitant Prescription of Opioids, and Benzodiazepines among Kidney Transplant Recipients

BACKGROUND

Gabapentinoids, commonly used for treating neuropathic pain, may be misused and coprescribed with opioid and benzodiazepine, increasing the risk of mortality and dependency among kidney transplant recipients.

METHODS

We identified adult kidney transplant recipients who enrolled in Medicare Part D in 2006-2017 using the United States Renal Data System/Medicare claims database. We characterized recipients' post-transplant concomitant prescription of gabapentinoids, opioids, and benzodiazepine stratified by transplant year and recipient factors (age, sex, race, and diabetes). We investigated whether concomitant prescriptions were associated with postkidney transplant mortality using Cox regression. Models incorporated inverse probability weighting to adjust for confounders.

RESULTS

Among 63,359 eligible recipients, 13% of recipients filled at least one gabapentinoid prescription within 1 year after kidney transplant. The prevalence of gabapentinoid prescriptions increased by 70% over the study period (16% in 2017 versus 10% in 2006). Compared with nonusers, gabapentinoids users were more likely to have diabetes (55% versus 37%) and obesity (46% versus 34%). Of the 8509 recipients with gabapentinoid prescriptions, 45% were coprescribed opioids, 7% were coprescribed benzodiazepines, and 3% were coprescribed both opioids and benzodiazepines. Compared with no study prescriptions, gabapentinoid monotherapy (adjusted hazard ratio [aHR]=1.25; 95% confidence interval [CI], 1.16 to 1.32) and combination therapy (gabapentinoids and opioids [aHR=1.49; 95% CI, 1.39 to 1.60], gabapentinoids and benzodiazepines [aHR=1.46; 95% CI, 1.03 to 2.08], and coprescribing all three [aHR=1.88; 95% CI, 1.18 to 2.98]) were all associated with a higher risk of postkidney transplant mortality.

CONCLUSIONS

Gabapentinoid coprescription with both benzodiazepines and opioids among kidney transplant recipients increased over time. Kidney transplant recipients prescribed gabapentinoids had a higher risk of post-transplant mortality, and the risk was higher with opioids or benzodiazepine coprescription.

Perioperative Management in the Collegiate Athlete: An Integrated Approach

Collegiate athletes face rigorous physical, academic, and emotional demands. While significant attention has been paid to injury prevention among young athletes in the past two decades, orthopedic injury rates remain high among collegiate athletes, and a significant number will undergo surgical management for injuries each year. In this narrative review, we describe techniques for perioperative management of pain and stress after surgery in collegiate athletes. In particular, we outline pharmacologic and non-pharmacologic management of surgical pain, with a goal of minimizing opiate consumption. We emphasize a multi-disciplinary approach to optimizing post-operative recovery in collegiate athletes help minimize reliance on opiate pain medication. Additionally, we recommend that institutional resources should be harnessed to support athletes in their well-being, from a nutritional, psychological and sleep standpoint. Critical to success in perioperative pain management is the communication among the athletic medicine team members and with the athlete and family to address pain and stress management and encourage timely, safe return to play.

Understanding motivations and use typologies of gabapentin with opioid agonist medications

BACKGROUND

Prior research suggests a potential relationship between the nonmedical use of gabapentin and use of opioid agonist medications (OAMs), buprenorphine and methadone. However, this research has been limited in scope and understanding despite increases in gabapentin prescribing in opioid use disorder (OUD) treatment settings and increased detection in opioid overdose fatalities.

METHODS

Data were analyzed for 346 participants of a follow-up program to an ongoing national opioid surveillance program of new entrants to treatment for opioid use disorder. Data were sourced from a cross-sectional online survey distributed in July/August 2021.

RESULTS

Lifetime exposure to gabapentin was reported by 60.0 % of the sample, while lifetime history of nonmedical use was reported by 43.2 %. Of those nonmedically using gabapentin, 50.0 % did so while also on a dosage of either buprenorphine or methadone, with 28.4 % engaged in concurrent nonmedical use of both gabapentin and OATs. Motivations for concurrent nonmedical use included high-seeking (38.6 %), self-management of pain/physical symptoms (33.3 %), and self-management of OUD (22.2 %).

CONCLUSIONS

Gabapentin exposure in treatment-seeking persons with OUD appears to be quite common, and use, both medically and nonmedically, frequently occurs alongside OAMs. Motivations for concurrent nonmedical use of gabapentin and OATs mirrors motivations for off-label prescribing by healthcare providers, but may also serve as a form of self-management of OUD when OAM regimens are interrupted, insufficiently prescribed or prescribed at insufficient dosages. Further research should seek to understand the risks versus benefits of gabapentin in OAM treatment settings.

Neurosteroids (allopregnanolone) and alcohol use disorder: From mechanisms to potential pharmacotherapy

Alcohol Use Disorder (AUD) is a multifaceted relapsing disorder that is commonly comorbid with psychiatric disorders, including anxiety. Alcohol exposure produces a plethora of effects on neurobiology. Currently, therapeutic strategies are limited, and only a few treatments - disulfiram, acamprosate, and naltrexone - are available. Given the complexity of this disorder, there is a great need for the identification of novel targets to develop new pharmacotherapy. The GABAergic system, the primary inhibitory system in the brain, is one of the well-known targets for alcohol and is responsible for the anxiolytic effects of alcohol. Interestingly, GABAergic neurotransmission is fine-tuned by neuroactive steroids that exert a regulatory role on several endocrine systems involved in neuropsychiatric disorders including AUD. Mounting evidence indicates that alcohol alters the biosynthesis of neurosteroids, whereas acute alcohol increases and chronic alcohol decreases allopregnanolone levels. Our recent work highlighted that chronic alcohol-induced changes in neurosteroid levels are mediated by epigenetic modifications, e.g., DNA methylation, affecting key enzymes involved in neurosteroid biosynthesis. These changes were associated with changes in GABAA receptor subunit expression, suggesting an imbalance between excitatory and inhibitory signaling in AUD. This review will recapitulate the role of neurosteroids in the regulation of the neuroendocrine system, highlight their role in the observed allostatic load in AUD, and develop a framework from mechanisms to potential pharmacotherapy.

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.

Alcohol use disorder with comorbid anxiety disorder: a case report and focused literature review

Background

Alcohol use disorder (AUD) and anxiety disorders (AnxD) are prevalent health concerns in clinical practice which frequently co-occur (AUD-AnxD) and compound one another. Concurrent AUD-AnxD poses a challenge for clinical management as approaches to treatment of one disorder may be ineffective or potentially counterproductive for the other disorder.

Case Presentation

We present the case of a middle-aged man with anxiety disorder, AUD, chronic pain, and gamma-hydroxybutyrate use in context of tapering prescribed benzodiazepines who experienced severe alcohol withdrawal episodes during a complicated course of repeated inpatient withdrawal management. After medical stabilization, the patient found significant improvement in symptoms and no return to alcohol use with a regimen of naltrexone targeting his AUD, gabapentin targeting both his AUD and AnxD, and engagement with integrated psychotherapy, Alcoholics Anonymous, and addictions medicine follow-up.

Conclusion

Proper recognition and interventions for AUD and AnxD, ideally with overlapping efficacy, can benefit individuals with comorbid AUD-AnxD. Gabapentin, tobacco cessation, and integrated psychotherapy have preliminary evidence of synergistic effects in AUD-AnxD. Meta-analysis evidence does not support serotoninergic medications (e.g. selective serotonin reuptake inhibitors) which are commonly prescribed in AnxD and mood disorders as their use has not been associated with improved outcomes for AUD-AnxD. Additionally, several double-blind placebo-controlled randomized trials have suggested that serotonergic medications may worsen alcohol-related outcomes in some individuals with AUD. Areas for future investigation are highlighted.

Gabapentin increases the abuse liability of alcohol alone and in combination with oxycodone in participants with co-occurring opioid and alcohol use disorder

BACKGROUND

People who have co-occurring Alcohol Use Disorder (AUD) and Opioid Use Disorder (OUD) carry a higher risk of adverse outcomes, including drug overdose. Early clinical and preclinical studies suggested that gabapentin may be effective in treating both disorders. The present study was designed to assess the effects of gabapentin on the subjective and physiological effects of oxycodone (OXY) and alcohol (ALC), alone and in combination.

METHODS

During an 8-week, inpatient, within-subject, randomized, double-blind, placebo-controlled crossover study, non-treatment seeking participants (N = 13; 12 M/1F; 44.1 ± 3 years of age) with OUD and AUD were maintained on oral morphine (120 mg daily). Under gabapentin (1800 mg/day) and placebo (0 mg/day) maintenance, participants completed nine separate test sessions (three sessions per week) during which they received an oral solution containing 0, 15, or 30 mg/70 kg OXY in combination with 0, 0.5, or 0.75 g/kg ALC. During test sessions, subjective effects and physiological responses were assessed repeatedly on 100-mm visual analog scales (VAS). The primary outcome variable was the VAS rating of drug liking after receiving the drug challenge.

RESULTS

Alcohol alone (but not oxycodone alone) produced dose-related increases in several positive subjective responses, including drug liking. Gabapentin significantly increased drug liking when given in combination with ALC and OXY + ALC (p < 0.05). Gabapentin did not clinically compromise respiration or other vital functions.

CONCLUSIONS

Gabapentin may increase the abuse liability of ALC and OXY + ALC in those with co-occurring OUD and AUD.

Association of State-Imposed Restrictions on Gabapentin with Changes in Prescribing in Medicare

BACKGROUND

Between August 2016 and July 2018, three states classified gabapentin as a Schedule V drug and nine states implemented prescription drug monitoring program (PDMP) regulation for gabapentin. It is highly unusual for states to take drug regulation into their own hands. The impact of these changes on gabapentin prescribing is unclear.

OBJECTIVE

To determine the effect of state-imposed regulation on gabapentin prescribing for Medicare Part D enrollees from 2013 to 2018.

DESIGN

Population-based difference-in-difference(DID) analysis study utilizing the Medicare Part D Prescriber Public Use File.

PARTICIPANTS

All eligible Medicare Part D prescribers excluding those outside of the fifty states and the District of Columbia were included in our analysis. Prescriber data and key sociodemographic variables were organized by state and year. States with a gabapentin schedule change or PDMP regulation enacted before 2019 were included in the intervention group. For the Schedule V DID analysis, a control group of the ten highest opioid-prescribing states was used.

INTERVENTIONS

States with gabapentin schedule changes or PDMP regulation before January 1, 2019, were included and compared to control states that did not implement these policies.

MAIN MEASURES

Total days' supply of gabapentin per enrollee per year was the primary outcome variable.

KEY RESULTS

The mean total days' supply of gabapentin per enrollee increased 41% from 19.71 to 27.81 total days' supply per enrollee per year between 2013 and 2018. After adjustment, Schedule V gabapentin regulation resulted in a reduction of 8.37 total days of gabapentin prescribed per enrollee (95% confidence interval of - 10.34 to - 6.39). In contrast, PDMP regulation resulted in a reduction of 1.01 total days of gabapentin prescribed per enrollee (95% confidence interval of - 1.74 to - 0.29).

CONCLUSIONS

Classifying gabapentin as a Schedule V drug results in substantial reduction in total days prescribed whereas PDMP regulation results in modest reduction.

Pharmacotherapies for Adults With Alcohol Use Disorders: A Systematic Review and Network Meta-analysis

BACKGROUND

We aimed to determine medications' comparative efficacy and safety for adults with alcohol use disorders.

METHODS

We searched eleven electronic data sources for randomized clinical trials with at least 4 weeks of treatment reporting on alcohol consumption (total abstinence and reduced heavy drinking), dropouts, and dropouts due to adverse events. We conducted network meta-analyses using random-effects, frequentist models, and calculated summary rate ratios (RRs) with 95% confidence intervals (CIs).

RESULTS

We included 156 trials (N = 27,334). Nefazodone (RR = 2.11; 95% CI, 1.42-3.13), aripiprazole (RR = 1.97; 95% CI, 1.36-2.88), carbamazepine (RR = 1.85; 95% CI, 1.03-3.32), and nalmefene (RR = 1.17; 95% CI, 1.01-1.35) were associated with the most dropouts. Baclofen (RR = 0.83; 95% CI, 0.70-0.97) and pregabalin (RR = 0.63; 95% CI, 0.43-0.94) caused fewer dropouts than placebo. Nalmefene (RR = 3.26; 95% CI, 2.34-4.55), fluvoxamine (RR = 3.08; 95% CI, 1.59-5.94), and topiramate (RR=2.18; 95% CI, 1.36-3.51) caused more dropouts from adverse events over placebo. Gamma-hydroxy-butyrate (RR = 1.90; 95% CI, 1.03-3.53), baclofen (RR = 1.80; 95% CI, 1.39-2.34), disulfiram (RR = 1.71; 95% CI, 1.39-2.10), gabapentin (RR = 1.66; 95% CI, 1.04-2.67), acamprosate (RR = 1.33; 95% CI, 1.15-1.54), and oral naltrexone (RR = 1.15; 95% CI, 1.01-1.32) improved total abstinence over placebo (Fig. 3C). For reduced heavy drinking, disulfiram (RR = 0.19; 95% CI, 0.10-0.35), baclofen (RR = 0.72; 95% CI, 0.57-0.91), acamprosate (RR = 0.78; 95% CI, 0.70-0.86), and oral naltrexone (RR = 0.81; 95% CI, 0.73-0.90) were efficacious against placebo.

CONCLUSIONS

The current meta-analyses provide evidence that several medications for AUDs are effective and safe and encourage the expanded use of these medications in the clinical setting. Our review found that acamprosate (2-3 g/d), disulfiram (250-500 mg/d), baclofen (30 mg/d), and oral naltrexone (50 mg/d) had the best evidence for improving abstinence and heavy drinking for patients with AUD.

PROSPERO

CRD42020208946.

Off-label and investigational drugs in the treatment of alcohol use disorder: A critical review

Compounds known to be successful in the treatment of alcohol use disorder include the aversive agent, Disulfiram, the glutamatergic NMDA receptor antagonist, Acamprosate, and the opioid receptor antagonists, Naltrexone and Nalmefene. Although all four are effective in maintaining abstinence or reduction of alcohol consumption, only a small percentage of patients receive pharmacological treatment. In addition, many other medications have been investigated for their therapeutic potential in the treatment of alcohol use disorder. In this review we summarize and compare Baclofen, Gabapentin, Topiramate, Ondansetron, Varenicline, Aripiprazole, Quetiapine, Clozapine, Antidepressants, Lithium, Neuropeptide Y, Neuropeptide S, Corticotropin-releasing factor antagonists, Oxytocin, PF-05190457, Memantine, Ifenprodil, Samidorphan, Ondelopran, ABT-436, SSR149415, Mifepristone, Ibudilast, Citicoline, Rimonabant, Surinabant, AM4113 and Gamma-hydroxybutyrate While some have shown promising results in the treatment of alcohol use disorder, others have disappointed and should be excluded from further investigation. Here we discuss the most promising results and highlight medications that deserve further preclinical or clinical study. Effective, patient-tailored treatment will require greater understanding provided by many more preclinical and clinical studies.

Alcohol Use

Unhealthy alcohol use-the consumption of alcohol at a level that has caused or has the potential to cause adverse physical, psychological, or social consequences-is common, underrecognized, and undertreated. For example, data from the 2020 National Survey on Drug Use and Health indicate that 7.0% of adults reported heavy alcohol use in the previous month, and only 4.2% of adults with alcohol use disorder received treatment. Primary care is an important setting for optimizing screening and treatment of unhealthy alcohol use to promote individual and public health.

Rates and types of urine drug screen false negative results compared with confirmatory toxicology testing in major trauma patients

BACKGROUND

Trauma centers are required to screen patients for alcohol use, and if necessary, intervene and refer to treatment (SBIRT). Similar screening for illicit drug use is recommended but not required. Urine drug screening (UDS) underestimates problematic substance use. This study aimed to estimate the types and rates of UDS false negatives (FN) compared to comprehensive testing by liquid chromatography-mass spectrometry (LC-MS) in trauma patients.

METHODS

We performed a prospective cohort study of deidentified urine samples from adult trauma and burn activation patients. Both UDS and LC-MS comprehensive testing of >200 analytes were performed by a reference laboratory on all samples. Iatrogenic medications were excluded from the FN count. Crosstab analyses were conducted for UDS versus LC-MS outcomes to establish FN types and rates. We dichotomized the results by creating an "intentionality" variable (intentional injuries by self/others versus accidental injuries). A series of crosstabs with odds ratios considered intentionality by substance class and demographics. Statistically significant variables by Chi-Square were assessed by logistic regression.

RESULTS

Psychoactive FN were detected in 56/100 urine samples analyzed; the most frequent included anticonvulsants (primarily gabapentin, N = 13), opioid agonists (N = 12), antihistamines (primarily diphenhydramine, N = 10), and phenethylamines (primarily bupropion, N = 5). Nonpsychoactive FN were detected in 70/100 samples; the most common were nicotine (N = 33), caffeine (N = 23), acetaminophen (N = 22), and antidepressants (N = 12). Of substance classes included in the UDS and also tested by LC-MS, FN occurred for opiates (3%), amphetamines (5%) and opioids (25%). Polypharmacy was associated with fall injuries in elderly patients. Cocaine (p = 0.015) and cannabinoids (p = 0.002) were significantly associated with intentionality.

CONCLUSIONS

Our results indicate that FN for potentially important psychoactive and nonpsychoactive substances are common when toxicologic testing is limited to routine UDS in trauma patients. We recommend expanding SBIRT in this patient population to include misuse of tobacco products, prescription analgesics, and over-the-counter antihistamines.

Raising the Question: Medication Mix-Up or Diversion

Max is an 8-year-old boy with autism spectrum disorder and long-standing challenges with sleep maintenance, the latter of which persist despite behavioral intervention and environmental modification. When Max wakes in the early morning hours, he tends to wander the house, which causes his mother to be awake to monitor his safety. Given the impact of Max's fragmented sleep on his functioning and that of his family, you begin a trial of gabapentin liquid to promote sleep maintenance. Soon after, Max's mother reports that he is sleeping through the night, for the first time in his life.Two months later, you receive a message from Max's mother requesting an early refill of his 90-day supply because of having spilled the bottle. You provide a new prescription, and Max's insurance company allows the early refill. Six weeks after that, Max's mother calls to say that she needs another gabapentin prescription because Max has run out. You confirm that she is giving the prescribed dose but are unsure as to why Max is out of medication weeks early. Given these events, you begin to question whether Max's gabapentin prescription is being diverted. What would you do next?

Prenatal Exposure to Gabapentin Alters the Development of Ventral Midbrain Dopaminergic Neurons

Background: Gabapentin is widely prescribed as an off-label drug for the treatment of various diseases, including drug and alcohol addiction. Approximately 83–95% of the usage of gabapentin is off-label, accounting for more than 90% of its sales in the market, which indicates an alarming situation of drug abuse. Such misuse of gabapentin has serious negative consequences. The safety of the use of gabapentin in pregnant women has always been a serious issue, as gabapentin can cross placental barriers. The impact of gabapentin on brain development in the fetus is not sufficiently investigated, which poses difficulties in clinical decisions regarding prescriptions.

Methods: The consequences effect of prenatal gabapentin exposure on the development of ventral midbrain dopaminergic neurons were investigated using three-dimensional neuronal cell cultures. Time-mated Swiss mice were used to isolate embryos. The ventral third of the midbrain was removed and used to enrich the dopaminergic population in 3D cell cultures that were subsequently exposed to gabapentin. The effects of gabapentin on the viability, ATP release, morphogenesis and genes expression of ventral midbrain dopaminergic neurons were investigated.

Results: Gabapentin treatment at the therapeutic level interfered with the neurogenesis and morphogenesis of vmDA neurons in the fetal brain by causing changes in morphology and alterations in the expression of key developmental genes, such as Nurr1, Chl1, En1, Bdnf, Drd2, and Pitx3. The TH + total neurite length and dominant neurite length were significantly altered. We also found that gabapentin could halt the metabolic state of these neuronal cells by blocking the generation of ATP.

Conclusion: Our findings clearly indicate that gabapentin hampers the morphogenesis and development of dopaminergic neurons. This implies that the use of gabapentin could lead to serious complications in child-bearing women. Therefore, caution must be exercised in clinical decisions regarding the prescription of gabapentin in pregnant women.