Prescribing drugs of dependence in general practice

Part C1 - Opioids - Chapter 1

Overview of opioid use in Australia

Last revised: 10 Jan 2022

Trends in opioid use in Australia

Worldwide opioid use has increased significantly, with a doubling of opioid analgesic prescriptions recorded between 2001–03 and 2011–13.1 While Australia only has around one-third the opioid consumption of the United States (US), opioid use here is still considered high and is on par with many European countries.1

Almost three million Australians received at least one Pharmaceutical Benefit Scheme (PBS) listed opioid analgesic between April 2013 and March 2014.2 Of these three million, around 150,000 people (5%) accounted for 61% of opioid use in terms of opioid defined daily doses (DDDs) supplied.2

Australian use of opioids is also increasing at a marginal rate. The rolling annual average of DDDs/1000 population/ day supplied has increased from 15.73 to 17.06 in the 10-year PBS data collection period (Figure 1).2 Paracetamol with codeine and tramadol were the two most commonly supplied opioids for most of that period.2

Repatriation Pharmaceutical Benefits Scheme opioid utilisation in DDDs/1000 population/day

Figure 1.

Repatriation Pharmaceutical Benefits Scheme opioid utilisation in DDDs/1000 population/day

Figure 1. Repatriation Pharmaceutical Benefits Scheme opioid utilisation in DDDs/1000 population/day

Reproduced from the Pharmaceutical Benefits Scheme Drug Utilisation Sub-committee (DUSC). Opioid analgesics: Overview. Canberra: Commonwealth of Australia, 2014. 

While overall use is only marginally increasing, there are changes in prescribing habits. The use of tramadol and morphine is decreasing, while use of fentanyl, buprenorphine, oxycodone with naloxone and hydromorphone is increasing (Figure 2).2,3 In particular, oxycodone prescribing has increased: since 2013, oxycodone has become the second most commonly used opioid.2 Numbers of oxycodone prescriptions are highest among older Australians.3

 Repatriation Pharmaceutical Benefits Scheme opioid utilisation in DDDs/1000 population/day by drug

Figure 2.

Repatriation Pharmaceutical Benefits Scheme opioid utilisation in DDDs/1000 population/day by drug

Figure 2. Repatriation Pharmaceutical Benefits Scheme opioid utilisation in DDDs/1000 population/day by drug

Reproduced from the Pharmaceutical Benefits Scheme Drug Utilisation Sub-committee (DUSC). Opioid analgesics: Overview. Canberra: Commonwealth of Australia, 2014. 

The most commonly sold opioid is over-the-counter (OTC) codeine. It is also the most accessible opioid in the community setting. Despite effectiveness and adverse event concerns, codeine is still used in quite high volumes.4 There has been a decision to up-schedule codeine to Schedule 4 (S4).5 This will come into effect in 2018.

Trends in non-medical use of opioids in Australia

The prevalence of non-medical use of pharmaceutical opioids (such as oxycodone and morphine) remains relatively low among the general Australian population.3 However, significant increases have been reported: between 2007 and 2010 the prevalence doubled from 0.2% to 0.4%.3 Refer to Problematic use of opioids.

Around half (52%) of PBS-listed opioids are used for the treatment of acutely painful conditions. The other half is almost equally divided between episodic and long-term treatment (25% and 23% respectively).6 However, it is difficult to determine what proportion of opioids is being used for acute pain, cancer pain, addiction medicine, chronic pain and selfmanagement of pain in Australia.6

Compared to people not receiving opioid analgesics, people prescribed opioids have been shown to be in poorer health with poorer functioning and higher levels of distress. It is unknown if this is due to pain-related conditions or to medication.6

Opioid prescribing appears to vary depending on patient demographics and geography.

Demographics and opioid prescribing

Patients with higher socioeconomic status indicators (eg higher education and income levels, full-time work status, private health insurance) are less likely to be on longer-term opioid analgesic treatment than older patients (Figure 3) and patients who do not speak English at home.6

 Repatriation Pharmaceutical Benefits Scheme opioid utilisation in DDDs/1000 population/day by age group

Figure 3.

Repatriation Pharmaceutical Benefits Scheme opioid utilisation in DDDs/1000 population/day by age group

Figure 3. Repatriation Pharmaceutical Benefits Scheme opioid utilisation in DDDs/1000 population/day by age group

Reproduced from the Pharmaceutical Benefits Scheme Drug Utilisation Sub-committee (DUSC). Opioid analgesics: Overview. Canberra: Commonwealth of Australia, 2014. 

Geography and opioid prescribing

Rates of opioid use are higher in areas that:4

  • are outside of major cities
  • are less populated
  • have more men and older people
  • have proportionally more low-income earning households
  • have greater proportions of people in jobs requiring physical labour.

Implications of prescribing variation

Demographic and geographic findings suggest that longer-term opioid analgesic prescribing occurs in patient groups who might be at higher risk of poor health. This is based on a wide range of health and non-health factors.6 Programs targeting inappropriate opioid prescribing and use need to focus on these groups and on areas outside of major cities.4

The RACGP is currently working with Primary Health Networks (PHNs) to address prescribing variation.

Refer to Strategies to improve appropriateness of opioid use

Prevalence of problematic use

The prevalence of non-medical use/misuse of pharmaceutical opioids (such as oxycodone and morphine) remains relatively low in Australia, despite a significant increase between 2007 and 2010 (from 0.2% to 0.4%).3

Incidence of problematic use

The incidence of problematic opioid use in primary care is hard to determine because terminology and classifications (eg ‘misuse’, ‘abuse’, ‘addiction’, ‘dependence’) are difficult to define or are very broad.7 Reported rates of problematic use range from <1% to 81%.7–9 Averaging across studies, the rate of misuse is between 21% and 29% and the rate of addiction is between 8% and 12%.7–9

Relationship between dose, duration of treatment and problematic use

Problematic use is dose dependent.9 For example, the rate of opioid dependence or abuse with low-dose chronic therapy is around 0.7%, but this increases to around 6% with high-dose chronic therapy.9 There are several factors associated with increased risk of problematic use. These include history of substance use disorder (SUD), younger age, major depression, and use of psychotropic medications.10

The mean duration between first use and problematic use of prescription opioids is 4.4 years (standard deviation 5.7 years), which presents a significant opportunity for intervention.11

Source of misused opioids

Medical practitioners are an important source of misused pharmaceuticals. However, they are not the main source of prescription opioids, with most misused opioids being obtained from dealers (via on-selling of prescribed opioids).11 Family and friends are the next most common source after dealers.11 This presents a challenge for strategies such as real-time prescription monitoring (RTPM) systems, as they will not pick up this activity.

RTPM is an important strategy in supporting safer opioid prescribing. While the RACGP strongly supports its implementation, it also recognises that this strategy is not the sole solution to curbing people misusing prescription opioids. It is therefore important for prescribers to recognise the limitations of these systems if solely relied on for the clinical assessment of drug-seeking behaviour.11 Refer to Real-time prescription monitoring.

Treatment seeking for pharmaceutical opioids increased from around 4800 to 7500 patients during the reporting period 2001/02 – 2011/12.3 As a percentage of all treatment episodes, pharmaceutical opioids represented 4% in 2001/02 and 5.1% in 2011/12.3 Morphine accounted for 25% of all treatment episodes for opioids other than heroin in 2011/12.3

Hospitalisation for pharmaceutical opioid poisoning is not common. Rates peaked in 2006/07 (83 per million persons) and have declined more recently (65 per million persons).12

Rate of opioid* hospital separations for poisoning, per million persons, 2001 to 2011

Figure 4.

Rate of opioid* hospital separations for poisoning, per million persons, 2001 to 201112

Figure 4. Rate of opioid* hospital separations for poisoning, per million persons, 2001 to 201112

*‘Opioid’ includes morphine, oxycodone and codeine, and excludes heroin, methadone and pethidine

Reproduced from the Australian Institute of Health and Welfare. National hospital morbidity database (NHMD). Canberra: AIHW.

Overall trend in overdose and age most affected

The number of deaths due to opioid overdose in Australia is growing. Between 2004 and 2014, there was a 61% increase in deaths due to accidental overdose (from 705 deaths in 2004 to 1137 in 2014).13 Of the people who died in 2014, 78% were aged between 30 and 59 years.13

Geographical trend in overdose

The overall increase in overdose deaths is being driven by those occurring in rural and regional areas. Between 2008 and 2014, there was an 83% increase in deaths in these areas (from 3.1 deaths per 100,000 to 5.7 per 100,000).13 In the same time period in metropolitan areas the rate changed from 4.2 per 100,000 to 4.4 per 100,000.13

Overdose trend in Aboriginal and Torres Strait Islander peoples

Accidental deaths due to opioid overdose per capita for Aboriginal and Torres Strait Islander peoples has increased substantially. Between 2004 and 2014 there was an increase of 141% across the five jurisdictions with Aboriginal data; from 3.9 deaths per 100,000 in 2004 to 9.4 per 100,000 in 2014.13

Relationship between patient factors, opioid characteristics and overdose

Higher opioid dosages are associated with an increased risk of fatal overdose. There is a three-fold increase in mortality when comparing high-dose opioid (>200 mg oral morphine equivalent daily dose [OMEDD]) relative to low-dose opioids (<20 mg OMEDD); however, the differences in absolute rates are quite low.14

Refer to Metabolism and duration of activity

Additionally, the risk of fatal overdose increases with:15

  • slow-release and long-duration opioids
  • co-prescription of opioids and benzodiazepines
  • sleep-disordered breathing
  • reduced renal or hepatic function
  • older age
  • pregnancy
  • mental health disorders including SUDs.

In Victoria, 80% of all drug overdoses from 2001 to 2013 involved prescription medications, and pharmaceutical opioids contributed to half of all drug-overdose deaths during that time.3 Fatal overdosing with pharmaceutical opioids is related to dose and duration of action.3,16,17

 Annual frequency of overdose deaths involving most frequent contributing individual drugs, Victoria 2009–16

Table 1.

Annual frequency of overdose deaths involving most frequent contributing individual drugs, Victoria 2009–1618

* Pentobarbitone prescribing to humans is not permitted in Australia, and the drug could be alternatively classified as illegal Routine post-mortem testing for pregabalin did not commence in Victoria until 2013

Reproduced from the Coroners Court of Victoria. Submission to the Inquiry into Drug Law Reform: Coronial recommendations on drug harm reduction. Melbourne: Coroners Court of Victoria, 2017.

In February 2017, the Coroners Court of Victoria in partnership with Turning Point Alcohol and Drug Centre concluded a study that examined the circumstances in which overdose deaths involving pharmaceutical drugs occur in Victoria. Regarding victims of overdose deaths:18

  • 71% had an SUD
  • 73% had a diagnosed mental illness
  • 49.6% had both a diagnosed mental illness and a documented SUD.

These patients often had a long-established clinical history of mental illness and drug dependence and had in most cases been known to the health system for extended periods of time (ie longer than 10 years).18

This conclusion underpins advice to avoid prescribing opioids to patients with comorbid alcohol or substance use disorders or polydrug use. GPs should consider seeking specialist opinion in the management of these patients. Patients who use two or more psychoactive drugs in combination (particularly benzodiazepines and opioids) and those with a history of substance misuse may be more vulnerable to major harms.

To support quality use of opioid medication and to reduce inappropriate opioid use, the RACGP supports:

  • standardised regulatory definitions of dependency and laws regarding drugs of dependence across all state and territory jurisdictions
  • an effective, national RTPM system and surveillance program
  • up-scheduling of codeine
  • improved analysis of PBS prescriptions to detect variation in prescribing drugs of dependence
  • improved categorisation of deaths from prescription drugs by the National Coronial Information System
  • state and territory health systems that support continual and coordinated care for patients with complex and/or multiple problems (eg combined SUDs, chronic pain and mental illness) in conjunction with general practice
  • improved use and management of opioids in acute settings
  • robust handover standards between primary, secondary and tertiary care
  • a national set of clinical indicators that monitors general practice prescribing drugs of dependence
  • national support for the ‘medical home’ concept (ie a patient having one general practice and preferably one GP to provide ongoing care and accountable prescribing of drugs of dependence)
  • improved governance and monitoring of opioid prescribing at a general practice level
  • adequate resourcing of systems of care within general practice for patients with
    • chronic non-cancer pain (CNCP)
    • SUDs
  • improved collaboration with pharmacies regarding use of drugs of dependence
  • education of consumers and health professionals, and expansion of non-pharmaceutical evidence-based treatments for chronic pain as crucial elements in preventive activities.

In 2020, changes to opioid indications were made across the class to help address misuse and harms in Australia. Significantly, the use of modified-release opioids is not indicated in chronic non-cancer/malignant pain, except in exceptional circumstances. 

Additional warnings and precautions for use were also added to Product Information and Consumer Medicine Information.

PBS restrictions and authority requirements have also been updated to reflect the new indications. More detailed information on the changes is available at Section 2.2.2 Pharmaceutical Benefits Scheme requirements for opioid prescriptions and Section 3.2 Specific opioids.

Real-time prescription monitoring

The RACGP is currently working with the Australian Institute of Health and Welfare (AIHW) to improve monitoring of opioids nationally.

The RACGP strongly supports the introduction of RTPM while recognising that the current state of research19 with evidence on effectiveness in reducing inappropriate prescribing,20 abuse, and opioid-related deaths is still evolving.21,22 Consumer impact and experiences with RTPM are not always positive.23 Administrators and clinicians should be clear about the intended objectives, risks and benefits of RTPM prior to implementation.24–26 While it is not a panacea to reduction in prescription drug harm, RTPM has a key role in supporting the high-quality use of drugs of dependence.

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