Characteristics of fatal tapentadol-related toxicity in Australia

Increased incidence of mixed drug toxicity deaths involving tapentadol - A forensic study

Tapentadol is a relatively new synthetic opioid analgesic prescribed for the management of moderate to severe pain. While tapentadol has been shown to be more effective than traditional opioid analgesics, it still carries the risk of addiction, abuse, and misuse. In Australia, tapentadol has become one of the top five most commonly prescribed opioid drugs, with prescriptions increasing by approximately 150,000 each year since it first became available. The rapid increase in tapentadol prescriptions has occurred in parallel to an increasing number of post-mortem tapentadol detections in South Australia (SA). While the number of deaths in SA related to tapentadol use was low in the current study, findings suggest that an increasing trend of deaths involving tapentadol will continue in parallel to a rapidly increasing number of prescriptions, mirroring trends associated with traditional opioids in SA. As a comparatively new opioid analgesic, monitoring future trends will be important to determine if additional prescribing education, intervention, or restrictions are required.

Tapentadol exposures and poisonings in Australia

INTRODUCTION

Tapentadol is an atypical opioid with mu-receptor affinity and noradrenaline reuptake inhibition approved for use in Australia in 2011. However, data on tapentadol poisoning are scarce.

OBJECTIVES

To investigate tapentadol poisonings and related deaths in Australia.

METHODS

We performed a retrospective review of tapentadol poisonings from New South Wales Poisons Information Centre (NSWPIC) and three toxicology units in Australia. The National Coronial Information System (NCIS) database was searched to determine the number of tapentadol-related deaths.

RESULTS

Between 2016 and 2020, 220 tapentadol calls were made to NSWPIC, with a 4.5-fold increase in tapentadol exposure calls. The median dose ingested was 575 mg (IQR: 300-1163 mg). Most overdoses included co-ingestions (75%), especially benzodiazepines (26%) and opioids (25%). From Jan 2016 to Dec 2021, 107 patients presented to the three toxicology units with tapentadol poisoning. The median dose ingested was 500 mg (IQR: 200-1400 mg). Most patients took co-ingestants (84%), including benzodiazepines (40%) and opioids (32%). Naloxone was administered in 39 patients (36%), 10 (9%) were intubated and the median length of stay was 18 h (IQR: 9-30). Thirty-five tapentadol-related deaths were recorded within NCIS between Jan 2015 and Oct 2021 with a median age of 51 years (IQR: 42-61 years).

CONCLUSION

There are increasing tapentadol poisonings and deaths reported to the NSWPIC, three toxicology units, and NCIS in Australia. Most tapentadol poisonings were taken with benzodiazepines and/or other opioids.