Opioid use and harms associated with a sustained-release tapentadol formulation: A post-marketing surveillance study

Quality use of publicly subsidised tapentadol in Australia: a population-based analysis

BACKGROUND

Sustained-release (SR) tapentadol was listed on Australia's Pharmaceutical Benefits Scheme (PBS) in 2014 for chronic severe pain requiring long-term opioid treatment. Dispensings have increased since listing despite declining trends in other PBS-listed opioids. Preferential prescribing of SR opioids may increase the risk of dependence and accidental overdose, particularly when used to treat acute pain.

AIMS

To explore the quality use of publicly subsidised tapentadol in Australia.

METHODS

We examined annual initiation rates and patterns of use of tapentadol (SR) in the dispensing records of a 10% random sample of PBS-eligible Australians (2014-2021). We used national tapentadol sales data to assess the proportion of sales attributable to the PBS.

RESULTS

Tapentadol initiation increased from 2014, peaking at 7.5/1000 adult population in 2019 before declining to 5.3/1000 in 2021. We identified 63 766 new users between 2014 and 2020, of whom 92.8% discontinued in the first year following initiation, 58.0% had only a single dispensing and 34.3% had no other opioids dispensed in the 3 months before or after initiation. 27.8% of new users were dispensed tapentadol on the same day as potentially interacting medicines. There was a sustained drop in the proportion of sales attributable to the PBS from June 2020 onwards, from an average of 69.1%, to 63.9% of pack sales.

CONCLUSIONS

Patterns of use suggest tapentadol (SR) is generally used for short duration. Although most tapentadol sold in Australia is subsidised, there is evidence of a shift towards private sales.

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.

Trends and psychosocial correlates of same day polysubstance use among people who inject drugs in Australia, 2012-2022

BACKGROUND

Polysubstance use is associated with negative health and social outcomes among people who inject drugs. We aimed to describe trends in polysubstance use and identify psychosocial correlates and associated drug use risk behaviours. We defined polysubstance use as intentional same day use of more than one of three drug classes: opioids, other non-opioid depressants (hereafter 'depressants'), and stimulants.

METHODS

We used 10 years (2012-2022, excluding 2020) of data from annual surveys in Australian capital cities with people who inject drugs (N=5657) to construct five mutually exclusive polysubstance use profiles: opioid-depressant, opioid-stimulant, stimulant-depressant, opioid-stimulant-depressant, and single drug class use. We examined time trends using the Mann Kendall test and identified correlates using multinomial logistic regression.

RESULTS

Same day polysubstance use was relatively common among this sample (43.6%). Opioid-depressant use was the most frequent polysubstance use profile, but this decreased over the study period (32.6% to 13.3%, p<0.001). This aligned with observed decreases in use of pharmaceutical opioids (p<0.001), opioid agonist treatment (p=0.007), and benzodiazepines (p=0.001). There was no evidence for any trend in the other polysubstance use profiles, although single drug class use increased (51.9% to 64.7%, p=0.031). The different polysubstance use profiles were variously associated with psychosocial factors, including unstable housing and very high psychological distress, and other drug use risk behaviours, including non-fatal overdose, receptive and/or distributive needle sharing, and reusing one's own needles.

CONCLUSION

Same day polysubstance use has remained relatively common among this sample over time, although the typology has changed. Collectively, our findings point to diverse drug use patterns among people who inject drugs and reiterate the need for a range of harm reduction, treatment, and support options.

Prescribing trend of tapentadol in a Sydney local health district

AIMS

Tapentadol, an opioid with mu-opioid receptor agonism and noradrenaline reuptake inhibition, has been increasingly used in Australia since 2011. However, data on hospital prescribing trends and indications are scarce. This study aimed to investigate hospital prescribing trends of tapentadol, oxycodone and tramadol in a Sydney local health district (LHD) and the indications for tapentadol hospital prescriptions in an Australian tertiary hospital.

METHODS

We analysed 5-year patient dispensing for tapentadol, oxycodone and tramadol from four hospitals in a Sydney LHD with data expressed as oral morphine equivalents (OME). We also conducted a retrospective review of 140 and 54 patients prescribed tapentadol at a tertiary hospital's surgical and spinal units in 2020.

RESULTS

Over 5 years in the Sydney LHD, there was a 19.5% reduction in total dispensing of these opioids from 1 225 210 to 986 477.5 OME milligrams. Decreases were specifically for oxycodone (-37.8% immediate-release, -65.2% sustained-release) and tramadol (-74.6% immediate-release, -70.1% sustained-release). Contrastingly, hospital prescriptions of tapentadol immediate-release increased by 223.2% between 2018-19 and 2020-21 while sustained-release increased by 17.9% from 2016-17 to 2020-21. By 2020-21, tapentadol overtook oxycodone to become the most prescribed opioid in the Sydney LHD (51.4%). At the hospital's surgical units, 137 (97.9%) patients were prescribed tapentadol for acute post-operative pain with the majority (54.0%) prescribed both immediate-release and sustained-release tapentadol, while 71.1% were prescribed for neuropathic pain in the spinal units.

CONCLUSION

In a Sydney LHD, tapentadol prescriptions increased significantly to become the preferred opioid analgesic. At the hospital's surgical units, off-label prescriptions of tapentadol sustained-release for acute post-operative pain were observed.

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.

Comparing opioid types in the persistence of opioid use following surgical admission: a study protocol for a retrospective observational linkage study comparing tapentadol and oxycodone in Australia

INTRODUCTION

Each year, an estimated two million Australians commence opioids, with 50 000 developing longer-term (persistent) opioid use. An estimated 3%-10% of opioid-naïve patients prescribed opioids following surgery develop persistent opioid use. This study will compare rates of persistent opioid use between two commonly used postoperative opioids, oxycodone and tapentadol, to understand if initial postoperative opioid type is important in determining longer-term outcomes.

METHODS AND ANALYSIS

A retrospective data linkage study that analyses administrative data from hospital and community pharmacies. Data will be obtained from at least four pharmacies that service large hospitals with comparable supplies of oxycodone and tapentadol. The study will include at least 6000 patients who have been dispensed a supply of oxycodone or tapentadol to take home following their discharge from a surgical ward. The primary outcome measure will be persistent opioid use at 3 months postdischarge for opioid naïve people who receive either immediate release tapentadol or immediate release oxycodone. Hierarchical logistic regression models will be used to predict persistent opioid use, controlling for covariates including comorbidities.

ETHICS AND DISSEMINATION

Ethics approval has been obtained through the Monash University Human Research Ethics Committee (29977). We will present project findings in a peer-reviewed journal article, in accordance with the REporting of studies Conducted using Observational Routinely-collected health Data statement.

Characteristics of fatal tapentadol-related toxicity in Australia

INTRODUCTION

Tapentadol is a centrally acting opioid analgesic prescribed for the treatment of moderate to severe pain. The study aimed to determine the characteristics of Australian toxicity deaths related to tapentadol.

METHODS

All cases in which tapentadol use was coded contributory to death (n = 159) were retrieved from the National Coronial Information System (1 July 2000-31 December 2020).

RESULTS

The mean age was 48.5 (18-81) and 56% were female. Documented histories of problems with chronic pain (66%), mental health (60.4%), substance use (44%) and injecting drug use (23.3%) were common. The majority of deaths were deemed unintentional (76.1%) and in 18.9% pre-existing disease was co-contributory. The median peripheral blood tapentadol concentration was 1.00 mg L^-1 (0.02-47.00), and the median aortic concentration was 2.05 mg L^-1 (0.10-30.00). In all cases, psychoactive drugs other than tapentadol were also detected, most commonly antidepressants (72.3%), opioids (66.7%), hypnosedatives (64.2%) and gabapentinoids (43.4%). Of cases where autopsies were conducted, 27.7% were diagnosed with cardiomegaly and 18.5% with severe coronary artery stenosis. Pulmonary oedema (68.1%), aspiration of vomitus (39.5%) and acute pneumonia (26.9%) were common.

DISCUSSION AND CONCLUSIONS

The typical tapentadol-related toxicity death involved unintentional death in the presence of multiple drugs, although a notable minority were intentional self-harm. Multiple morbidities were common. The identification and characteristics of these cases indicate that the adverse event profile of tapentadol needs to be considered in the setting of polypharmacy.

Comparing rates and characteristics of emergency department presentations related to pharmaceutical opioid poisoning in Australia: a study protocol for a retrospective observational study

INTRODUCTION AND AIMS

Pharmaceutical opioids are an important contributor to the global 'opioid crisis', and are implicated in 70% of Australia's opioid-related mortality. However, there have been few studies which consider the relative contribution of different pharmaceutical opioids to harm.We aim to compare commonly used pharmaceutical opioids in terms of (1) rates of harm, and (2) demographic and clinical characteristics associated with that harm.

METHOD AND ANALYSIS

Observational study of emergency department presentations for non-fatal poisoning related to pharmaceutical opioid use. Data from 2009 to 2019 will be extracted from the Victorian Emergency Minimum Dataset which contains data from public hospitals with dedicated emergency departments in Victoria, Australia's second most populous state. A combination of free-text and International Classification of Diseases 10th Revision codes will be used to identify relevant cases, with manual screening of each case to confirm relevance. We will calculate supply-adjusted rates of presentations using Poisson regression for all pharmaceutical opioid cases identified, separately for nine commonly prescribed pharmaceutical opioids (buprenorphine, codeine, fentanyl, methadone, morphine, oxycodone, oxycodone-naloxone, tapentadol, tramadol), and for a multiple opioid category. We will use multinomial logistic regression to compare demographic and clinical characteristics, such as triage category, across opioid types.

ETHICS AND DISSEMINATION

This work is conducted under approval 21427 from the Monash University Human Research Ethics Committee for ongoing injury surveillance. As per conditions of approval, cells of <5 will not be reported, though zeroes will be preserved. We will present project findings in a peer-reviewed journal article as well as at relevant scientific conferences.