1. Pregabalin use and misuse in Australia
Dr. Rose Crossin
Senior Research and Policy Officer

2. Misuse potential
Euphoric or euphoric mood is a potential adverse effect of taking pregabalin and dependence has been reported (Pfizer, product information sheet)
Has been associated with an increased risk of suicidal ideation and behaviours, and depression
CNS depressant effects
Potential for additive effects on respiration when ingested with other sedatives
As such consumer medication information suggests that:
Doctors need to be advised of a history of depression or substance abuse
Be alert to potential for dependence and / or psychiatric side effects
Concurrent other medication / substance use needs to be considered

3. International evidence of misuse and harms
First approved for medical use in 2004 and on the market in 2005
Academic papers on misuse begin from ~2011
Online reports of recreational pregabalin misuse in Europe (Schifano 2011)
Poly-drug use with opioids highly prevalent in pregabalin-related deaths in Finland (Hakkinen 2014)
Increased prevalence of pregabalin in intentional drug overdoses in Ireland (Daly 2017)
High prevalence of misuse in those who use opioids or have psychiatric co-morbidities (Evoy 2017)
All occurring against a background of rapidly increasing prescribing and use

4. The Australian Context
Rapidly increasing number of prescriptions from 2013
By 2015, pregabalin was one of the costliest drugs on the PBS (Mabbott 2015)
But, as at the start of 2018 there were no studies on misuse or harms related to pregabalin in Australia ….
Question: Is Australia seeing similar patterns of misuse and harms related to pregabalin as had been seen internationally?

5. Cairns, Schaffer et al. 2018

6. Methods Study set in NSW Data sources:
PBS 10% sample: Jul 2012 to Feb 2017, dispensing data
Poisons Information Centre database: Jan 2004 to Dec 2016, calls relating to intentional exposure
Toxicology unit databases: Jan 2012 to Dec 2015, intentional pregabalin exposure in poisoned patients at hospitals (deliberate self-poisoning, recreational use, and misuse)
Coronial database: 2005 to 2016, deaths where pregabalin was related (from free-text information, not toxicologically confirmed)
Aims: to identify dispensing trends, identify people at high risk of misuse, understand demographics of intentional overdoses, and estimate trends in pregabalin-related deaths

7. Trends in dispensing and intentional poisonings
Cairns, R., Schaffer, A. L., Ryan, N., Pearson, S. A., & Buckley, N. A. (2018). Rising pregabalin use and misuse in Australia: trends in utilization and intentional poisonings. Addiction.

8. Identifying high-risk groups for misuse
14.7% of people prescribed pregabalin were considered high-risk for misuse
Defined as: prescribed more and higher strengths, had more prescribers, more likely to be co-prescribed opioids and benzodiazepines
More likely to be younger and male
More likely to have concessional status
High-risk users received 50.8% of pregabalin by volume

9. Characteristics of pregabalin overdoses and deaths
Compared to other gabapentin and carbamazepine, those who overdosed with pregabalin were:
More likely to co-ingest opioids, benzodiazepines, other illicit drugs, and alcohol
78% were prescribed pregabalin
64% had a documented substance misuse history
Compared to overdoses, pregabalin-related deaths were:
More likely to be male
More likely to involve co-ingestion (80% involved pharmaceutical opioids, 67% involved benzodiazepines)
The majority (81%) were not in paid employment
The majority (66%) of deaths were coded as unintentional, 19% intentional, remainder undetermined

10. Crossin, Scott et al. 2018

11. Methods Study set in Victoria
Data from the Ambo Project: Jan 2012 to Dec 2017
Pregabalin misuse defined as:
A person prescribed pregabalin consumes more than prescribed quantity / frequency
A person consumes pregabalin prescribed to someone else
Prescribed pregabalin is taken with a combination of other substances
Aims: compare trends in ambulance attendances relative to prescribing, characterise populations experiencing harm, assess co-occurring other sedative use and harms to self, compare characteristics of attendances between those who misuse pregabalin with and without other sedatives

12. Ambulance attendances are increasing with prescriptions
Crossin, R., Scott, D., Arunogiri, S., Smith, K., Dietze, P. M., & Lubman, D. I. (2019). Pregabalin misuse‐related ambulance attendances in Victoria, 2012–2017: characteristics of patients and attendances. Medical journal of Australia, 210(2),

13. Characteristics of attendances
1,201 pregabalin-related ambulance attendances in 6 years:
50% were male, 50% were female
27% were aged 30-39
24% were aged 40-49
49% had a high-risk history (of depression, or self-harm, or suicidal ideation, or suicide attempt, or AOD misuse)
Most commonly history of depression and history of suicide attempt

14. Co-occurring issues with pregabalin misuse
Graphs adapted from data in: Crossin, R., Scott, D., Arunogiri, S., Smith, K., Dietze, P. M., & Lubman, D. I. (2019). Pregabalin misuse‐related ambulance attendances in Victoria, 2012–2017: characteristics of patients and attendances. Medical journal of Australia, 210(2),

15. Pregabalin misuse with and without other sedatives
Men more likely than women to misuse pregabalin with other sedatives
When pregabalin was misused with other sedatives, more likely to have GCS<13
No significant differences in co-occurring self-injurious behaviours, based on presence / absence of other sedatives
Increased medical risk when pregabalin misused with other sedatives, but no difference in psychiatric risk

16. Overall conclusions
Significant increase in pregabalin prescribing, misuse, and harms
Many high-risk users in Australia (~86,000 in 2016)
Growing harms in vulnerable groups
Low SES
Strong overlap with SUD history
Strong overlap with a high-risk psychiatric history
Extensive poly-substance use (particularly benzodiazepines, alcohol, and opioid analgesics) which increases overdose risk
Associated with both intentional and unintentional overdoses

17. Limitations
Only limited data available on whether pregabalin was prescribed to the individual (78% from NSW hospital toxicology, no data for Vic)
Neither study included private prescriptions (off-label indications), and the condition for which pregabalin was prescribed is unknown
NSW coronial data did not have toxicological testing for pregabalin
Vic ambulance data not toxicologically confirmed
Large population studies, not specific to high-risk groups
Neither study can discuss causality, just associated outcomes

18. Recommendations For regulators For doctors For users
Consideration of scheduling changes (recently re-scheduled in US and UK)
Consider inclusion in SafeScript in Victoria
For doctors
Precautions when co-prescribing other sedatives
Communication of interaction risks with other sedatives
Undertake risk assessment for misuse
Avoid off-label prescribing for indications without a strong evidence base
Review indications, including psychiatric history
For users
Awareness of potential adverse effects, incl. risks when taken with other substances
Disclosure of relevant history to prescribing doctors

19. Outstanding questions
No good estimates of dependence in Australia, just misuse and harms
What are the primary motivations for misuse?
Are there long-term outcomes from pregabalin misuse?
Do trends and harms differ in high-risk populations?
Is information about potential harms and risks getting through?
How can we get information to those misusing diverted pregabalin?