Global variation in prescribed opioid use

In this step, Dr Fausto Morell-Ducos, Consultant in Anaesthesia and Pain Medicine at University College London Hospitals, discusses how differences in prescribing practices translate into the observed differences in prescribed opioid use globally.

As you have discovered in the previous steps, several different factors are thought to have contributed to the current epidemic of opioid overuse, addiction and overdose in the US.

The super-sized consumption of prescription opioids which led to this crisis in North America is not driven by a larger clinical need and is much higher than that of many other high-income countries which have a similar prevalence of pain in their populations, with no corresponding improvement in the quality of pain management reported [1].

How do things compare in the rest of the world?

There is a global opioid problem. Worldwide, opioid prescriptions more than doubled between 2001 and 2013, and this has been linked to increased opioid-related harm in Canada, Australia and the United Kingdom (UK). Europe, with some notable exceptions, seems to have been less affected [2].

According to one global surveillance study, which analysed opioid analgesic sales data in hospital and retail settings for 76 countries [3], there is some evidence that increasing awareness of the dangers of opioid-overprescription and policy changes are bearing fruit.

According to this study, global pharmaceutical opioid use has declined by 30% between 2009 and 2019. This reduction has been primarily driven by decreased opioid prescription in the US and Germany. In 2009, Germany had the highest consumption rate, followed by the US and Canada. Opioid use has declined by 58% in Germany, 48% in the US, and 37% in Canada from 2009 to 2019. Despite this, these three countries remain among the highest opioid-prescribing countries in the world (see Figure 1).

Figure 1. Change in the national opioid consumption rate between 2009 and 2019 in morphine milligram equivalents (MME) per 1,000 inhabitants per day. Colour scale is continuous with darker shades indicating negative values and lighter shades indicating positive values. Countries with no data are shaded in grey. From Jayawardana et al (2021) [3].

The figure above introduces a concept that you’ll encounter multiple time over this course, that of the morphine milligram equivalent (MME). This is sometimes also expressed as ‘oral morphine equivalent’ (OME) or as the ‘morphine equivalent dose’ (MED). As you’ll learn more about in Week 2, different opioids have different potencies relative to that of morphine (eg oral oxycodone is approximately twice as potent as oral morphine). MME is used to compare the potency of an opioid dose relative to morphine by using a conversion factor (so 10 mg of oral oxycodone would be equal to 20 MME or 20 mg OME). MME is a helpful concept when comparing opioid use between people who are taking different opioid drugs. You will explore the concept in more detail in Step 2.9.

The UK, on the other hand, has seen an increase in prescription of opioid analgesics, which have roughly doubled between 2000 and 2015. Although opioid prescriptions have decreased gradually since 2016, it remains in the unenviable position as world leader with the highest prescribed opioid dose in daily MME per capita in 2019 (see Figure 2).

Figure 2. Opioid consumption rate by country for 2019 in MMEs per 1,000 inhabitants per day. Colours represent the 2014 World Bank income classification of high, upper-middle, and low- and lower-middle income countries. From Jayawardana et al (2021) [3].

Although there is a correlation between GDP and prescription opioid use, there is considerable heterogeneity within high-income countries, with France’s opioid use being nine times that of Japan, for example. Countries from the Arabian Peninsula have a much lower opioid prescription rate than other countries with comparable economies. This may reflect cultural and social attitudes towards the use of opioids in pain management.

Spain, Portugal, Switzerland, the Netherlands, Poland and Norway all sharply increased their opioid consumption rate between 2009 and 2019. In the period 2011-2016 an increase in opioid-related deaths of more than 20% was described in the United States, Canada, Sweden, Norway, Ireland, and England & Wales. A similar increase, however, has not been seen in countries such as Germany, Austria, Belgium, Denmark and the Netherlands. This suggests that adequate regulatory measures – including the kind of interventions we will be discussing in this course – are compatible with improving access to opioids without leading to the increases in opioid-related deaths which have been seen in North America, the UK and Australia.

References

_{1. United Nation Office on Drugs and Crime. World Drug Report 2022. United Nations (2022).}

_{2. Robert M, Jouanjus E, Khouri C, Fouilhé Sam-Laï N, Revol B. The opioid epidemic: A worldwide exploratory study using the WHO pharmacovigilance database. Addiction 2023;118:771-775.}

_{3. Jayawardana S, Forman R, Johnston-Webber C, Campbell A, Berterame S, de Joncheereet C, et al. Global consumption of prescription opioid analgesics between 2009-2019: a country-level observational study. EClinMed 2021;42:101198.}