Concurrent use of prescription gabapentinoids with opioids and risk for fall-related injury among older US Medicare beneficiaries with chronic noncancer pain: A population-based cohort study

Changes in orthopaedic prescribing patterns of gabapentin associated with state prescribing restrictions: A large database study

Background

Safety concerns have emerged regarding gabapentin, and as a result several states have recently adopted regulations for prescribing gabapentin. As gabapentin has been commonly used off-label for pain management in orthopedics, a retrospective analysis was conducted to investigate trends in orthopedic prescriptions of gabapentin considering novel state regulations.

Methods

The study analyzed gabapentin prescription patterns of orthopedic surgeons from 2013 to 2021 recorded in annual Medicare Part D Public Use Files across the fifty states and Washington DC. Datasets were filtered to only include orthopedic providers. Gabapentin prescriptions were grouped based on state of practice for each surgeon per year for total gabapentin claims, supply in days, and beneficiaries. Twelve states classified gabapentin as a Schedule V drug, seven instituted a Prescription Drug Monitoring Program (PDMP), and 32 had no restrictions. States were grouped by prescription restriction type. Two-tailed t-tests were conducted to compare the annual average percent of change for gabapentin claims, supply, and beneficiaries per state following regulation.

Results

Following regulation, the general trend of gabapentin claims, beneficiaries, and supply was a blunting in the annual rate of change. States with PDMPs for gabapentin had the lowest overall claims, supply, and beneficiaries. States with no regulation eclipsed states with Schedule V classifications for the most beneficiaries and supply in 2019 and claims in 2020. Six of 11 PDMP states had significant reductions across gabapentin claims, beneficiaries, and supply following regulation, compared to three of seven Schedule V states.

Conclusion

The impact that state-based regulations had on gabapentin claims, supply, and beneficiaries was variable, likely due to different requirements in the enactment of their novel PDMP or Schedule V classifications. To optimize the implementation of these regulatory programs, public health authorities may adopt regulatory strategies that resemble those from states that were more effective in regulating gabapentin prescriptions.

Level of evidence

Level III, Therapeutic Study.

Evaluation of Drug-Drug Interactions in Pharmacoepidemiologic Research

Drug-drug interactions (DDIs) represent a significant concern for clinical care and public health, but the health consequences of many DDIs remain largely underexplored. This knowledge gap underscores the critical need for pharmacoepidemiologic research to evaluate real-world health outcomes of DDIs. In this review, we summarize the definitions commonly used in pharmacoepidemiologic DDI studies, discuss common sources of bias, and illustrate through examples how these biases can be mitigated.

Prescribing Patterns and Off-Label Use of Gabapentinoid Agents at Dhulikhel Hospital, Nepal: A Cross-Sectional Study

Purpose

Gabapentinoids are mainly prescribed for neuropathic pain and certain seizure disorders, but their off-label use has increased significantly. This rise raises concerns about the insufficient evidence supporting some applications, as well as potential risks of misuse, dependence, and adverse effects. The study aims to examine the prescribing patterns and off-label use of gabapentinoids at Dhulikhel Hospital (DH), Nepal, focusing on understanding the extent of off-label practices and patient knowledge regarding their medications.

Patients and Methods

A cross-sectional survey of 385 adult patients prescribed gabapentinoids was conducted at the outpatient pharmacy of DH. Data were collected via patient interviews and prescriptions. Off-label use was assessed according to the licensed indications of the US Food and Drug Administration (FDA) and the UK British National Formulary (BNF). Statistical analysis was performed using Statistical Package for the Social Sciences version 26.

Results

Among patients prescribed gabapentinoids, 73.0% received gabapentin while 27.0% were prescribed pregabalin. Most patients were middle-aged females with comorbid conditions, primarily orthopedic outpatients. Off-label use was prevalent, with 96.1% of prescriptions being off-label by FDA indications and 28.1% by BNF indications. Pregabalin was prescribed at a sub-therapeutic dose (75 mg/day) for neuropathic pain. Patient knowledge about gabapentinoids was found to be poor, particularly regarding side effects and drug interactions.

Conclusion

This study highlights the extensive off-label and sub-therapeutic use of gabapentinoids at Dhulikhel Hospital and reveals significant gaps in patient knowledge. This emphasizes the need for stricter prescribing guidelines, improved healthcare provider education, and better patient information to optimize the use and minimize risks. The frequent prescription of low-dose pregabalin for neuropathic pain raises the possibility that it may be used for night-time sedation rather than for pain management, indicating the need for further investigation.

Risk of adverse outcomes during gabapentinoid therapy and factors associated with increased risk in UK primary care using the clinical practice research datalink: a cohort study

ABSTRACT

Growing evidence from pharmacovigilance data and postmortem toxicology reports highlights the misuse potential of gabapentinoids. This study aimed to investigate the risk of serious adverse outcomes (drug misuse, overdose, major trauma), and their risk factors, in primary care patients who are prescribed gabapentinoids. Using the UK Clinical Practice Research Datalink, a matched cohort study calculated adverse event rates separately for gabapentinoid-exposed and unexposed cohorts. In the exposed cohort, event rates for exposure to a range of potential risk factors were calculated. Event rates were compared using Cox proportional hazards models, adjusted for age, sex, deprivation, previous mental health diagnosis, and coprescribing with potentially interacting medicines. Substance misuse (gabapentin adjusted hazard ratio [95% CI]: 2.40 [2.25-2.55]), overdose (2.99 [2.56-3.49]), and major trauma (0-2.5 years: 1.35 [1.28-1.42]; 2.5 to 10 years: 1.73 [1.56-1.95]) were more common among patients prescribed gabapentinoids than matched individuals who were not. The association with overdose was stronger for pregabalin than gabapentin. All adverse outcomes were significantly associated with smoking, history of substance misuse, overdose, or a mental health condition and prescription of opioids, benzodiazepines, antidepressants, and Z-drug hypnotics (eg, gabapentin hazard ratios for association of concurrent opioid use: misuse 1.49 [1.47-1.51]; overdose 1.87 [1.78-1.96]; major trauma 1.28 [1.26-1.30]). Our findings highlight the importance of careful patient selection when prescribing gabapentinoids and the need to educate prescribers about the risks of these drugs, particularly in combination with other central nervous system depressants.

The efficacy and potential mechanisms of pyrotinib in targeting EGFR and HER2 in advanced oral squamous cell carcinoma

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) plays an important role in the progression of multiple solid tumors and induces resistance to epidermal growth factor receptor (EGFR) target treatment. However, the expression status and the clinical significance of HER2 in oral squamous cell carcinoma (OSCC) is still controversial. Pyrotinib (PYR) is a promising novel EGFR/HER2 dual inhibitor, whose efficacy in OSCC has not been determined.

METHODS

57 locally advanced de novo OSCC patients were included in this study to investigate the relationship between the HER2 expression levels and the prognosis by the tissue microarray analysis (TMA). In vitro and in vivo experiments were performed to retrieve the efficacy of PYR in OSCC. The main downstream of HER2 was evaluated by western blotting in OSCC cell lines and xenograft tumors to explore the potential mechanism of PYR.

RESULTS

This study revealed the primary tumor of OSCC had higher HER2 expression levels. Patients with HER2 overexpression had poor overall survival (P < 0.014) and poor disease free survival (P < 0.042). In vitro, PYR suppressed the proliferation, colony formation and migration of OSCC cells. It also promoted apoptosis of OSCC cells and induced cell cycle arrest. Furthermore, PYR was able to inhibit the occurrence and development of OSCC effectively in vivo. Western blotting revealed that PYR suppressed OSCC by inhibiting the phosphorylation of HER2, AKT and ERK.

CONCLUSIONS

This study exhibited the anti-OSCC effects of PYR in vitro and in vivo, and demonstrated PYR inhibited OSCC cells by inducing apoptosis via the HER2/ AKT and ERK pathway. The result of this study also indicated locally advanced OSCC patients might benefit from HER2 assay and EGFR/HER2 dual inhibit treatment.

The Association of Gabapentin Initiation with Cognitive and Behavioral Changes in Older Adults with Cognitive Impairment: A Retrospective Cohort Study

BACKGROUND

Although gabapentin has been increasingly prescribed to older adults, the relation between gabapentin initiation and longer-term neurocognitive changes is not well understood. Thus, this study aimed to examine the association of gabapentin initiation with cognitive and motor function decline in older adult participants with cognitive impairment.

METHODS

A retrospective cohort study was conducted using the National Alzheimer's Coordinating Center Uniform Data Set (2005-March 2023). Participants with cognitive impairment at the visit of gabapentin initiation (i.e., index visit) were included. Using the incidence density sampling method, up to nine non-users were randomly selected for each initiator. Cognitive decline over 1 year was defined as any increase in Clinical Dementia Rating global score (CDR®GLOB) or a 1-point increase in CDR® sum of boxes (CDR®SB). Functional status decline over 1 year was defined as at least a 3-point increase in the Functional Activities Questionnaire (FAQ) sum or a 0.3-point increase of mean of FAQ. Motoric decline over 1 year was defined as new clinician reports of gait disorder, falls, and slowness. To mitigate confounding and selection bias, joint stabilized inverse probability of treatment weights and censoring weights were used. Analyses compared index with index + 1 and index + 2 visits.

RESULTS

For the study of cognitive and functional status decline, we included 505 initiators (mean age [SD] 78.8 [7.4]; male = 45%) and 4545 non-users (79.2 [7.6]; 50.1%). For the study of motor decline, we included 353 initiators (78.3 [7.2]; 42.8%) and 3177 non-users (78.5 [7.4]; 48.1%). Gabapentin initiation was not statistically associated with decline on CDR®GLOB, CDR®SB, FAQ sum, or mean FAQ at the index + 1 or index + 2 visits. However, gabapentin initiation was significantly associated with increased odds of new falls at the index + 2 visit (odds ratio [95% confidence interval] 2.5 [1.3, 4.6]).

CONCLUSIONS

Over 1 or 2 years of follow-up, gabapentin initiation was not associated with decline in cognitive or functional status but was associated with increased odds of falling among research participants with cognitive impairment.

Comparative Risk of Injury with Concurrent Use of Opioids and Skeletal Muscle Relaxants

Concurrent use of skeletal muscle relaxants (SMRs) and opioids has been linked to an increased risk of injury. However, it remains unclear whether the injury risks differ by specific SMR when combined with opioids. We conducted nine retrospective cohort studies within a US Medicaid population. Each cohort consisted exclusively of person-time exposed to both an SMR and one of the three most dispensed opioids-hydrocodone, oxycodone, and tramadol. Opioid users were further divided into three cohorts based on the initiation order of SMRs and opioids-synchronically triggered, opioid-triggered, and SMR-triggered. Within each cohort, we used Cox proportional hazard models to compare the injury rates for different SMRs compared to methocarbamol, adjusting for covariates. We identified 349,543, 139,458, and 218,967 concurrent users of SMRs with hydrocodone, oxycodone, and tramadol, respectively. In the oxycodone-SMR-triggered cohort, the adjusted hazard ratios (HRs) were 1.86 (95% CI, 1.23-2.82) for carisoprodol and 1.73 (1.09-2.73) for tizanidine. In the tramadol-synchronically triggered cohort, the adjusted HRs were 0.69 (0.49-0.97) for metaxalone and 0.62 (0.42-0.90) for tizanidine. In the tramadol-SMR-triggered cohort, the adjusted HRs were 1.51 (1.01-2.26) for baclofen and 1.48 (1.03-2.11) for cyclobenzaprine. All other HRs were statistically nonsignificant. In conclusion, the relative injury rate associated with different SMRs used concurrently with the three most dispensed opioids appears to vary depending on the specific opioid and the order of combination initiation. If confirmed by future studies, clinicians should consider the varying injury rates when prescribing SMRs to individuals using hydrocodone, oxycodone, and tramadol.

Incidence and Prevalence of Pain Medication Prescriptions in Pathologies with a Potential for Chronic Pain

BACKGROUND

Heightened risks of dependence, addiction, anxiolytic effects, or prescription overdose death due to long-term use of pain medication have increased awareness about extended pain medication use in chronic pain populations. The goal of this study was to evaluate the incidence and prevalence of pain medication prescriptions from 2012 to 2022 in common pathologies with a potential for chronic pain.

METHODS

A retrospective cohort study was conducted using electronic health records from TriNetX (Cambridge, Massachusetts) Global Collaborative Network. For 10 distinct cohorts (total n = 9,357,584 patients), pain medication prescriptions were extracted for five classes, namely nonsteroidal anti-inflammatory drug (NSAIDs) and acetaminophen, opioids, gabapentinoids, neuropathic mood agents, and muscle relaxants. Annual incidence and prevalence of each class of medication were evaluated for the past 11 yr.

RESULTS

From 2012 to 2022, there was a significant increase in prescriptions of NSAIDs, except for patients with fibromyalgia, and persistent spinal pain syndrome (PSPS) type 2. Interestingly, over time, prescriptions of opioids in patients with complex regional pain syndrome, endometriosis, osteoarthritis, and PSPS type 2 increased, as did prescriptions of muscle relaxants for all cohorts except those with fibromyalgia. Incidence of prescriptions of neuropathic mood agents is high for patients with complex regional pain syndrome (both types) and PSPS type 2. Only for benzodiazepines did there seem to be a decline over the years, with a significantly decreased time trend in patients with complex regional pain syndrome type 1, fibromyalgia, and PSPS type 2.

CONCLUSIONS

During the last 11 yr, an increase in incidence of NSAIDs and acetaminophen, opioids, neuropathic agents, and muscle relaxants was observed. Only prescriptions of benzodiazepines significantly decreased over time in specific cohorts. Overall, patients with PSPS type 2 and complex regional pain syndrome (both types) consume a broad variety of pain medication classes.

EDITOR’S PERSPECTIVE

Prevalence and trend of central nervous system-active medication polypharmacy among US commercially insured adults with vs without early-onset dementia: a multi-year cross-sectional study

BACKGROUND

Limited data exist on the prevalence and trend of central nervous system (CNS)-active medication polypharmacy among adults with early-onset dementia (EOD) and whether these estimates differ for adults without EOD but with chronic pain, depression, or epilepsy, conditions managed by CNS-active medications.

METHODS

A multi-year, cross-sectional study using 2012-2021 MarketScan Commercial Claims data was conducted among adults aged 30 to 64 years with EOD and those without EOD but having a diagnosis of chronic pain, depression, or epilepsy as comparison groups. For each disease cohort, the primary outcome was CNS-active medication polypharmacy defined as concurrent use of ≥ 3 CNS-active medications on the US Beers Criteria list that overlapped for > 30 consecutive days during 12 months following a randomly selected medical encounter with the disease diagnosis. A separate multivariate modified Poisson regression model was used to estimate time trends in CNS polypharmacy in each disease cohort. Differences in trend estimates between EOD and non-EOD disease cohorts were examined by an interaction between EOD status and yearly time.

RESULTS

From 2013 to 2020, the annual crude prevalence of CNS polypharmacy was higher among adults with EOD (21.2%-25.0%) than adults with chronic pain (5.1%-5.9%), depression (14.8%-21.7%), or epilepsy (20.0%-22.3%). The adjusted annual prevalence of CNS polypharmacy among patients with EOD did not significantly change between 2013 and 2020 (adjusted prevalence rate ratio [aPRR], 0.94; 95% CI, 0.88-1.01), whereas a significant decreasing trend was observed among non-EOD cohorts with chronic pain (aPRR, 0.66; 95% CI, 0.63-0.69), depression (aPRR, 0.81; 95% CI, 0.77-0.85), and epilepsy (aPRR, 0.86; 95% CI, 0.83-0.89). The interaction analysis indicated that patients with epilepsy and depression (vs with EOD) had a decreasing probability of CNS-active medication polypharmacy over time (aPRR, 0.98 [95% CI, 0.98-0.99]; P < .001 for interaction for both conditions).

CONCLUSIONS

The prevalence of CNS polypharmacy among US commercially insured adults with EOD (vs without) was higher and remained unchanged from 2013 to 2021. Medication reviews of adults with EOD and CNS polypharmacy are needed to ensure that benefits outweigh risks associated with combined use of these treatments.

Deprescribing interventions for gabapentinoids in adults: A scoping review

The emerging issue of rising gabapentinoid misuse is being recognized alongside the lack of current evidence supporting the safe and effective deprescribing of gabapentinoids. This scoping review aimed to assess the extent and nature of gabapentinoid deprescribing interventions in adults, either in reducing dosages, or prescribing of, gabapentinoids. Electronic databases were searched on 23 February 2022 without restrictions. Eligible studies included randomized, non-randomized and observational studies that assessed an intervention aimed at reducing/ceasing the prescription/use of a gabapentinoid in adults for any indication in a clinical setting. The research outcomes investigated the type of intervention, prescribing rates, cessations, patient outcomes and adverse events. Extracted outcome data were categorized as either short (≤3 months), intermediate (>3 but <12 months) or long (≥12 months) term. A narrative synthesis was conducted. The four included studies were conducted in primary and acute care settings. Interventions were of dose-reducing protocols, education and/or pharmacological-based approaches. In the randomized trials, gabapentinoid use could be ceased in at least one third of participants. In the two observational trials, gabapentinoid prescribing rates decreased by 9%. Serious adverse events and adverse events specifically related to gabapentinoids were reported in one trial. No study included patient-focused psychological interventions in the deprescribing process, nor provided any long-term follow-up. This review highlights the lack of existing evidence in this area. Due to limited available data, our review was unable to make any firm judgements on the most effective gabapentinoid deprescribing interventions in adults, highlighting the need for more research in this area.

Fall-related Injuries and Opioid Administration Among Veterans With Dementia in US Department of Veterans Affairs Community Living Centers

OBJECTIVES

Opioid use is associated with fall-related injuries (FRI) among older adults, especially those with dementia. We examined FRI following changes in national opioid safety initiatives over 3 regulatory periods [preinitiatives baseline (period 1): October 2012 to June 2013; post-Veteran Affairs (VA) opioid safety initiative (period 2): January 2014 to November 2015; post-VA and CDC opioid prescribing guidelines (period 3): March 2017 to September 2018] among Department of VA Community Living Center (CLC) long-stay residents with dementia.

DATA

VA provided and purchased care records, Medicare claims, CLC Minimum Data Set (MDS) assessments. VA bar-code medication administration data, VA outpatient prescription refill data, and Medicare Part D data were used to capture medication from inpatient, outpatient, and Medicare sources.

SETTINGS AND PARTICIPANTS

A total of 12,229 long-stay CLC residents with dementia between October 2012 and September 2018.

METHODS

We applied Veteran-regulatory period level (1) generalized linear model to examine the unadjusted and adjusted trends of FRI, and (2) difference-in-difference model with propensity score weighting to examine the relationship between opioid safety initiatives and FRI in 3 regulatory periods. We applied propensity score weighting to enable the cohorts in periods 2 and 3 had similar indications for opioid administration as in period 1.

RESULTS

FRI prevalence per month among CLC residents with Alzheimer disease and related dementias decreased from 3.1% in period 1 to 1.6% and 1.2% in periods 2 and 3, and the adjusted probability of FRI was 17% and 40% lower in periods 2 and 3 compared with period 1. The any, incident, and continued opioid administration were significantly associated with higher FRI, whereas the differences in FRI probabilities between opioid and nonopioid users had no significant changes over the 3 regulatory periods.

CONCLUSIONS

FRI was reduced among CLC residents with Alzheimer disease and related dementias receiving care in VA CLCs over the 3 regulatory periods, but the FRI reduction was not significantly associated with opioid safety initiatives. Other interventions that potentially targeted falls are likely to have helped reduce these fall events. Future studies could examine whether opioid use reduction ultimately benefitted nursing home residents by focusing on other possible outcomes or whether such reduction only resulted in more untreated pain.

Trends and correlates of concurrent opioid and benzodiazepine and/or gabapentinoid use among Ontario nursing home residents

BACKGROUND

A concern with long-term opioid use is the increased risk arising when opioids are used concurrently with drugs that can potentiate their associated adverse effects. The drugs most often encountered are benzodiazepines (BZDs) and gabapentinoids. Our study objectives were to examine trends in the concurrent use of opioids and BZDs, or gabapentinoids, in a Canadian nursing home population over an 11-year period, and current resident-level correlates of this concurrent use.

METHODS

We conducted a population-based, repeated cross-sectional study among Ontario nursing home residents (>65 years) dispensed opioids between April 2009 and February 2020. For the last study year, we examined cross-sectional associations between resident characteristics and concurrent use of opioids with BZDs or gabapentinoids. Linked data on nursing home residents from clinical and health administrative databases was used. The yearly proportions of residents who were dispensed an opioid concurrently with a BZD or gabapentinoid were plotted with percent change derived from log-binomial regression models. Separate modified Poisson regression models estimated resident-level correlates of concurrent use of opioids with BZDs or gabapentinoids.

RESULTS

Over the study period, among residents dispensed an opioid there was a 53.2% relative decrease (30.7% to 14.4%) in concurrent BZD and a 505.4% relative increase (4.4% to 26.6%) in concurrent gabapentinoid use. In adjusted models, increasing age and worsening cognition were inversely associated with the concurrent use of both classes, but most other significantly related covariates were unique to each drug class (e.g., sex and anxiety disorders for BZD, pain severity and presence of pain-related conditions for gabapentinoids).

CONCLUSIONS

Co-administration of BZDs or gabapentinoids in Ontario nursing home residents dispensed opioids remains common, but the pattern of co-use has changed over time. Observed covariates of concurrent use in 2019/20 suggest distinct but overlapping resident populations requiring consideration of the relative risks versus benefits of this co-use and monitoring for potential harm.