Non-medical Use of Prescription Gabapentinoids (Gabapentin and Pregabalin) in Five European Countries

Secular trends in gabapentinoid dispensing by compensated workers with low back pain: a retrospective cohort study

OBJECTIVES

The increase in gabapentinoid prescribing is paralleling the increase in serious harms. To describe the low back pain workers compensation population whose management included a gabapentinoid between 2010 and 2017, and determine secular trends in, and factors associated with gabapentinoid use.

METHODS

We analysed claim-level and service-level data from the Victorian workers' compensation programme between 1 January 2010 and 31 December 2017 for workers with an accepted claim for a low back pain injury and who had programme-funded gabapentinoid dispensing. Secular trends were calculated as a proportion of gabapentinoid dispensings per year. Poisson, negative binomial and Cox hazards models were used to examine changes over time in incidence and time to first dispensing.

RESULTS

Of the 17 689 low back pain claimants, one in seven (14.7%) were dispensed at least one gabapentinoid during the first 2 years (n=2608). The proportion of workers who were dispensed a gabapentinoid significantly increased over time (7.9% in 2010 to 18.7% in 2017), despite a reduction in the number of claimants dispensed pain-related medicines. Gabapentinoid dispensing was significantly associated with an opioid analgesic or anti-depressant dispensing claim, but not claimant-level characteristics. The time to first gabapentinoid dispensing significantly decreased over time from 311.9 days (SD 200.7) in 2010 to 148.2 days (SD 183.1) in 2017.

CONCLUSIONS

The proportion of claimants dispensed a gabapentinoid more than doubled in the period 2010-2017; and the time to first dispensing halved during this period.

Pilot RCT comparing low-dose naltrexone, gabapentin and placebo to reduce pain among people with HIV with alcohol problems

BACKGROUND

To estimate the effects on pain of two medications (low-dose naltrexone and gabapentin) compared to placebo among people with HIV (PWH) with heavy alcohol use and chronic pain.

METHODS

We conducted a pilot, randomized, double-blinded, 3-arm study of PWH with chronic pain and past-year heavy alcohol use in 2021. Participants were recruited in St. Petersburg, Russia, and randomized to receive daily low-dose naltrexone (4.5mg), gabapentin (up to 1800mg), or placebo. The two primary outcomes were change in self-reported pain severity and pain interference measured with the Brief Pain Inventory from baseline to 8 weeks.

RESULTS

Participants (N = 45, 15 in each arm) had the following baseline characteristics: 64% male; age 41 years (SD±7); mean 2 (SD±4) heavy drinking days in the past month and mean pain severity and interference were 3.2 (SD±1) and 3.0 (SD±2), respectively. Pain severity decreased for all three arms. Mean differences in change in pain severity for gabapentin vs. placebo, and naltrexone vs. placebo were -0.27 (95% confidence interval [CI] -1.76, 1.23; p = 0.73) and 0.88 (95% CI -0.7, 2.46; p = 0.55), respectively. Pain interference decreased for all three arms. Mean differences in change in pain interference for gabapentin vs. placebo, and naltrexone vs. placebo was 0.16 (95% CI -1.38, 1.71; p = 0.83) and 0.40 (95% CI -1.18, 1.99; p = 0.83), respectively.

CONCLUSION

Neither gabapentin nor low-dose naltrexone appeared to improve pain more than placebo among PWH with chronic pain and past-year heavy alcohol use.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT4052139).

Cohort study of new off-label gabapentin prescribing in chronic opioid users

INTRODUCTION

Gabapentin is commonly prescribed as an off-label adjunct to opioids because of its safer risk profile. Recent evidence has shown an increased risk of mortality when coprescribed with opioids. Therefore, we aimed to evaluate whether the addition of off-label gabapentin in patients with chronic opioid use is associated with a reduction in opioid dosage.

METHODS

We performed a retrospective cohort study of patients with chronic opioid use with a new off-label gabapentin prescription (2010-2019). Our primary outcome of interest was a reduction in opioid dosage measured via oral morphine equivalents (OME) per day after the addition of a new off-label gabapentin prescription.

RESULTS

In our cohort of 172,607 patients, a new off-label gabapentin prescription was associated with a decrease in opioid dosage in 67,016 patients (38.8%) (median OME/day reduction:13.8), with no change in opioid dosage in 24,468 patients (14.2%), and an increase in opioid dosage in 81,123 patients (47.0%) (median OME/day increase: 14.3). A history of substance/alcohol use disorders was associated with a decrease in opioid dosage after the addition of a new off-label gabapentin (aOR 1.20, 95% CI 1.16 to 1.23). A history of pain disorders was associated with a decrease in opioid dosage after the initiation of a new gabapentin prescription including arthritis (aOR 1.12, 95% CI 1.09 to 1.15), back pain (aOR 1.10, 95% CI 1.07 to 1.12), and other pain conditions (aOR 1.08, 95% CI 1.06 to 1.10).

CONCLUSIONS

In this study of patients with chronic opioid use, an off-label gabapentin prescription did not reduce opioid dosage in the majority of patients. The coprescribing of these medications should be critically evaluated to ensure optimal patient safety.

Content and sentiment analysis of gabapentinoid-related tweets: An infodemiology study

INTRODUCTION

The increasing number of gabapentinoid (pregabalin and gabapentin) harms, including deaths observed across countries is concerning to health-care professionals and policy makers. However, it is unclear if the public shares these concerns. This study aimed to describe posts related to gabapentinoids, conduct a content analysis to identify common themes and describe adverse events or symptoms.

METHODS

Keywords of 'pregabalin' or 'Lyrica' or 'gabapentin' or 'Neurontin' were used to search for related tweets posted by people in the community between 8 March and 7 May 2021. Eligible tweets included a keyword in the post. We extracted de-identified data which included descriptive data of the total number of posts over time; and data on individual tweets including date, number of re-tweets and post content. Data were exported separately for pregabalin- and gabapentin-related tweets. A 20% random sample was used for the thematic analysis.

RESULTS

There were 2931 pregabalin-related tweets and 2736 gabapentin-related tweets. Thematic analysis revealed three themes (sharing positive experiences and benefits of taking gabapentinoids, people voicing their negative experiences, and people seeking opinions and sharing information). Positive experiences of gabapentinoids were related to sharing stories and giving advice. This was contrasted to negative experiences including ineffectiveness, withdrawals, side effects and frustration related to cost and insurance coverage. Brain fog was the most common adverse symptom reported. Gabapentinoid-related deaths were only mentioned in three tweets.

DISCUSSION

The increasing public health concern of gabapentinoid-related deaths was not translated to Twitter discussions.

A Meta-Analysis Showing the Quantitative Evidence Base of Preemptive Pregabalin for Postoperative Pain from Cancer-Related Surgery

Background and Objectives: As an adjunct to postoperative multimodal analgesic regimens, pregabalin has been reported in reducing postoperative acute pain and opioid consumption. However, there is only a small amount of evidence for preemptive pregabalin in patients undergoing cancer-related surgery. This systematic review was conducted to integrate high-quality evidence to evaluate the preemptive analgesic effects of pregabalin in cancer-related surgery. Materials and Methods: Seven electronic databases were searched in a combination of subject terms and free words. Efficacy and safety of preemptive pregabalin on postoperative pain for cancer-related surgery were evaluated by assessing resting and dynamic pain scores postoperatively, cumulative morphine equivalent consumption, time to first analgesic request, hemodynamic parameters, and the safety indicators. Results: Thirteen trials were incorporated for quantitative synthesis. The pooled results showed administration of pregabalin preoperatively is clinically significant for improving resting (weighted mean difference (WMD), -1.53 cm; 95% CI, -2.30 to -0.77) and dynamic (WMD, -1.16 cm; 95% CI, -2.22 to -0.11) pain severity scores at 2 h postoperatively and prolonging time to first analgesic request (WMD, 2.28 h; 95% CI, 0.79 to 3.77) in cancer-related surgery. Preemptive pregabalin was also statistically effective in some other pain indicators but would increase the risk of pregabalin-related side effects after surgery. Conclusions: Our findings do not support the administration of pregabalin in doses larger than 300 mg when put in cancer-related surgery. Taken together, more high-quality research particularly focused on the optimal dosages and timing of pregabalin in cancer-related surgery is needed in the future to establish stronger evidence for therapeutic effects.

Benefits and harms of treatments for chronic non-specific low back pain without radiculopathy: Systematic review and meta-analysis

BACKGROUND CONTEXT

Currently, there are no published studies that compare non-pharmacological, pharmacological and invasive treatments for chronic low back pain in adults and provide summary statistics for benefits and harms.

PURPOSE

The aim of this review was to compare the benefits and harms of treatments for the management of chronic low back pain without radiculopathy and to report the findings in a format that facilitates direct comparison (Benefit-Harm Scale: level 1 to 7).

DESIGN

Systematic review and meta-analysis of randomized controlled trials, including trial registries, from electronic databases up to 23^rd May 2022.

PATIENT SAMPLE

Adults with non-specific chronic low back pain, excluding radicular pain in any clinical setting.

OUTCOME MEASURES

Comparison of pain at immediate-term (≤2 weeks) and short-term (>2 weeks to ≤12 weeks) and serious adverse events using the Benefit-Harm Scale (level 1 to 7).

METHODS

This was a registered systematic review and meta-analysis of randomized controlled trials. Interventions included non-pharmacological (acupuncture, spinal manipulation), pharmacological and invasive treatments compared to placebo. Best evidence criteria was used. Two independent reviewers conducted eligibility assessment, data extraction and quality appraisal.

RESULTS

The search retrieved 17,362 records. Three studies provided data on the benefits of interventions, and 30 provided data on harms. Studies included interventions of acupuncture (n=8); manipulation (n=2); pharmacological therapies (n=9), including NSAIDs and opioid analgesics; surgery (n=8); and epidural corticosteroid injections (n=3). Acupuncture (standardized mean difference (SMD) -0.51, 95%CI -0.88 to -0.14, n=1 trial, moderate quality of evidence, benefit rating of 3) and manipulation (SMD -0.39, 95%CI -0.56 to -0.21, n=2 trials, moderate quality of evidence, benefit rating of 5) were effective in reducing pain intensity compared to sham. The benefit of the other interventions was scored as uncertain due to not being effective, statistical heterogeneity preventing pooling of effect sizes, or the absence of relevant trials. The harms level warnings were at the lowest (eg, indicating rarer risk of events) for acupuncture, spinal manipulation, NSAIDs, combination ingredient opioids, and steroid injections, while they were higher for single ingredient opioid analgesics (level 4) and surgery (level 6).

CONCLUSIONS

There is uncertainty about the benefits and harms of all the interventions reviewed due to the lack of trials conducted in patients with chronic non-specific low back pain without radiculopathy. From the limited trials conducted, non-pharmacological interventions of acupuncture and spinal manipulation provide safer benefits than pharmacological or invasive interventions. However, more research is needed. There were high harms ratings for opioids and surgery.

How prevalent and severe is addiction on GABAmimetic drugs in an elderly German general hospital population? Focus on gabapentinoids, benzodiazepines, and z-hypnotic drugs

OBJECTIVE

Gabapentinoids (GPT) are reported to be increasingly misused by opioid- and polydrug-users, but the addictive potential of GPT outside of these populations remains understudied. Investigations comparing GPT abuse and dependence liability to that of other commonly prescribed Central Nervous System-acting medications are therefore warranted. We provide a comparison of GPT-abuse/dependence to that of other GABAmimetics within an elderly population.

DESIGN

DSM-IV-TR-based data (previously prospectively collected by SKID-I-interview) from a random sample of elderly patients admitted to a metropolitan German general hospital were reviewed. The prevalence and severity of GPT, benzodiazepine (BDZ), and z-hypnotic drug (ZD)-abuse and -dependence were compared, stratified also by mono-substance (no concurrent current or previous substance use) and de novo-substance (first)-abuse and -dependence states.

RESULTS

Among 400 patients (75 ± 6.4 years old; 63% females), neither current nor past abuse of BDZ, ZD or GPT, nor other illicit substances was observed. Dependence upon BDZ, ZD or GPT was observed among 55 (13.75%) individuals. The related lifetime/12-month prevalence-rates were: dependence condition (BDZ: 7%/2.45%; ZD: 4.25%/4.25%; GPT: 2.75/2.5%); mono-dependence condition (BDZ: 2.25%/0.75%; ZD: 1%/1%, GPT: 0%/0%); de novo-dependence condition (BDZ: 2.75%/1.75%; ZD: 1%/1%, GPT: 0.5%/0.5%). Opioid analgesic-dependence (N = 43/400) was significantly more frequently linked with BDZ than with GPT (p < 0.01) [Correction added on 29 December 2021, after first online publication: In the sentence 'Opioid analgesic-dependence…', the term 'and ZD' has been deleted]. For all three GABAmimetic classes, most mono- and de novo-dependence states were mild-to-moderate and lasted 2-6 years (median).

CONCLUSION

GABAmimetic-dependence was usually mixed with other substance-dependences. Every third to fourth instance of BDZ- or ZD-dependence was a mono-dependence condition, while a pure GPT-dependence was absent in this elderly (and illicit substance-naïve) population.

Prevalence of Gabapentinoids and Central Nervous System Depressant Drugs, and Their Association with Risk Factors for Respiratory Depression in Primary Care Patients

BACKGROUND AND OBJECTIVES

Warnings have been published regarding an increased risk of severe respiratory depression in patients receiving gabapentinoids either alone or in combination with opioids and/or anxiolytics/hypnotics, especially in individuals with a respiratory risk factor. The aim is to report the prevalence of the use of gabapentinoids alone and associated with central nervous system depressant drugs, and possible associated risk factors for respiratory depression, in order to identify the most fragile population and establish intervention strategies.

METHODS

We performed a cross-sectional study using computerized prescription records from the northern area of Barcelona at Catalan Institute of Health for 363,007 inhabitants registered during 2021. Patients aged ≥ 18 years with one or more gabapentinoid prescription were included. Age, gender, polypharmacy, adjusted morbidity groups, quantity of chronic diseases, and the number of consultations per year were independent variables. Four age categories were defined (18-64 years, then 64-74, 75-84, and those aged 85 years or older). Descriptive and inferential statistics were employed. Level of statistical significance was 5% (p ≤ 0.05). For the analysis, the SPSS program (version 22) was employed.

RESULTS

Of the study sample, 9218 were prescribed gabapentidoids. Overall prevalence of use was 3.0% (women 3.6%, men 2.4%). On the whole, women used more drugs than men. In contrast to their younger counterparts, consumption increased 2.6 times, 3.8 times, and 4.0 times in the 65-74 age group, 75-84 age group, and those aged ≥ 85 years, respectively. Mean age was 65.59 (±15.80) years. Polypharmacy (5-9 drugs) was present in 41.7% of the patients and extreme polypharmacy (≥ 10 drugs) was present in 39.3% of the patients. Regarding renal function, 2396 patients (25.9%) had glomerular filtration that required dose adjustment (76.1% with gabapentin and 23.8% with pregabalin). In 141 patients (5.9%), a total daily dose higher than that authorized (109 with gabapentin, 29 with pregabalin) had been prescribed. The prescription of gabapentinoids combined with opioids and/or anxiolytics/hypnotics was significantly associated with (i) polypharmacy (5-9 drugs, OR: 3.42 [95% CI 3.00-3.88]; ≥ 10 drugs, OR 8.72 [95% CI 7.42-10.25]); (ii) quantity of chronic diseases, OR: 1.14 (95% CI 1.11-1.17); (iii) augmented number of consultations/year, OR: 1.01 (95% CI 1.00-1.01); (iv) female gender, OR: <  1 for men, OR: 0.66 (95% CI 0.60-0.73); (v) being elderly: 65-74 years, OR: 0.71 (95% CI 0.62-0.81); 75-84 years, OR: 0.62 (95% CI 0.54-0.71); ≥85 years, OR: 0.68 (95% CI 0.58-0.81); and (vi) adjusted morbidity groups, OR: 0.90 (95% CI 0.88-0.92), (p <  0.0001).

CONCLUSION

Exposure to gabapentinoids occurs in a non-negligible percentage of the population. Greater numbers of combinations of gabapentinoids and opioids and/or anxiolytics/hypnotics were associated with polypharmacy, quantity of chronic diseases, and augmented number of consultations, but not with male gender, older age, and adjusted morbidity groups.

Evaluation of Medicine Abuse Trends in Community Pharmacies: The Medicine Abuse Observatory (MAO) in a Region of Southern Europe

The misuse of medicines is a global public health concern that needs to be taken into consideration and requires actions across all government sectors and society. The aim of this study is to identify trends of drug abuse in Catalonia, a region of Spain located in the South of Europe. For this purpose, a questionnaire-based detection tool was created and implemented in 60 community pharmacies. Out of 548 questionnaires (98.4%), 64.2% of participants were men and the highest age proportion was 25-35 years (31.4%). Potential drug abuse was the highest in urban pharmacies (84.9%). The main drug class involved were benzodiazepines (31.8%), codeine (19.3%), tramadol (7.5%), methylphenidate (5.8%), gabapentinoids (5.8%), cycloplegic drops (4.4%), z-drugs (2.6%), piracetam (2.2%), dextromethorphan (1.6%) and clomethiazole (1.1%). The majority of drugs were requested without prescription (58.6%) and through probably forged prescriptions (23.7%). Slightly less than half (49.8%) of the patients request frequently to the pharmacist, especially in rural and mountain pharmacies (73.3% and 88.5%, respectively). A small proportion (10.8%) were requested with intimidation. Pharmacists only supplied in 21.7% of the cases. This study has demonstrated the suitability of the new detection system, being a useful approach to replicate in other locations with similar needs.