Authors' Reply to Bonnet et al. "Abuse and Misuse of Pregabalin and Gabapentin: A Systematic Review Update"

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.

Association between chiropractic spinal manipulation and gabapentin prescription in adults with radicular low back pain: retrospective cohort study using US data

OBJECTIVES

Radicular low back pain (rLBP) is often treated off-label with gabapentin or by chiropractors using chiropractic spinal manipulative therapy (CSMT). To date, no studies have examined the association between these interventions. We hypothesised that adults under 50 years of age receiving CSMT for newly diagnosed rLBP would have reduced odds of receiving a gabapentin prescription over 1 year-follow-up.

DESIGN

Retrospective cohort study.

SETTING

US network including linked medical records, medical claims and pharmacy claims of >122 million patients attending large healthcare organisations (TriNetX), queried 15 June 2023, yielding data from 2017 to 2023.

PARTICIPANTS

Adults aged 18-49 were included at their first occurrence of rLBP diagnosis. Exclusions were severe pathology, other spinal conditions, on-label gabapentin indications and gabapentin contraindications. Propensity score matching controlled for variables associated with gabapentin use and receipt of prescription medication over the preceding year.

INTERVENTIONS

Patients were divided into CSMT or usual medical care cohorts based on the care received on the index date of rLBP diagnosis.

PRIMARY AND SECONDARY OUTCOME MEASURES

OR for gabapentin prescription.

RESULTS

After propensity matching, there were 1635 patients per cohort (mean age 36.3±8.6 years, 60% women). Gabapentin prescription over 1-year follow-up was significantly lower in the CSMT cohort compared with the usual medical care cohort, with an OR (95% CI) of 0.53 (0.40 to 0.71; p<0.0001). Sensitivity analyses revealed early divergence in cumulative incidence of prescription; and no significant between-cohort difference in a negative control outcome (gastrointestinal medication) suggesting adequate control for pharmacological care preference.

CONCLUSIONS

Our findings suggest that US adults receiving CSMT for newly diagnosed rLBP have significantly reduced odds of receiving a gabapentin prescription over 1-year follow-up compared with those receiving usual medical care. Results may not be generalisable and should be replicated in other healthcare settings and corroborated by a prospective study to reduce confounding.

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.