Characteristics of fatal gabapentinoid-related poisoning in Australia, 2000–2020

Abstract

Introduction

Gabapentinoids are centrally active GABA agonists whose use has increased substantially in the past decade. The current study aimed to provide a comprehensive clinical profile of a national case series of fatal poisonings related to gabapentinoids.

Methods

Retrospective study of all deaths due to drug toxicity in Australia in which gabapentinoids were a contributory mechanism, retrieved from the National Coronial Information System (2000–2020). Information was collected on case characteristics, toxicology and major organ pathology.

Results

A total of 887 cases were identified, with a mean age of 45.7 years and 55.2% being male. Death was due to accidental toxicity in 81.3% of cases and intentional in 18.7%. Pre-existing disease was co-contributory to drug toxicity in 19.5%. Pregabalin was present in 92.9% of cases, with a median blood concentration of 7.6 mg/L (range 0.1–850.0 mg/L). Gabapentin was present in 7.2%, with a median blood concentration of 9.5 mg/L (range 0.5–1940.0 mg/L). Both pregabalin and gabapentin were present in five cases. No other gabapentinoids were detected. Drugs other than gabapentinoids were present in 99.8%, most frequently opioids (90.1%), hypnosedatives (76.9%) and antidepressants (60.5%). A body mass index in the obese range was seen in 45.4%. Clinically significant pre-existing disease was common, notably cardiomegaly (24.9%), emphysema (20.2%), nephrosclerosis (18.7%) and severe hepatic steatosis (11.7%).

Conclusions

The concomitant use of other drugs was close to universal, with CNS depressants predominating. Mental health problems, chronic pain and substance misuse were prominent.

Keywords:

• Pregabalin
• gabapentin
• mortality
• toxicity
• toxicology
• circumstances

Acknowledgements

The authors acknowledge the Victorian Department of Justice and Community Safety as the source organisation for the data presented here, and the National Coronial Information System as the data source. We would like to thank the staff at the National Coronial Information System.

Disclosure statement

AP has received untied educational grants from Seqirus and Mundipharma for post-marketing surveillance of pharmaceutical opioids. This organisation had no role in study design, analysis and reporting, and funding support was for work unrelated to this project. MF has received untied educational grants from Seqirus, Mundipharma and Indivior for post-marketing surveillance of pharmaceutical opioids. This organisation had no role in study design, analysis and reporting, and funding support was for work unrelated to this project.

Additional information

Funding

This work was funded by the National Drug & Alcohol Research Centre at the University of New South Wales. The National Drug & Alcohol Research Centre is supported by funding from the Australian Government. AP is funded by an NHMRC Investigator Fellowship.