The US prescription opioid epidemic

In this step, Dr Fausto Morell-Ducos, Consultant in Anaesthesia and Pain Medicine at University College London Hospitals, explains how the well-intentioned but ultimately misguided application of palliative care principles to chronic non-cancer pain populations, as well as unfounded claims by pharmaceutical companies regarding the lack of risk of dependence of opioids, contributed to the opioid crisis in North America.

Many statistics can be used to describe the extent and severity of the Opioid Crisis in the United States. Between 2001 and 2015, it is estimated that almost 530,000 Americans died from opioid-related overdoses [1], while in the years 2015 to 2017 life expectancy in the United States decreased for the first time in more than 60 years, in part because of the Opioid Crisis [2]. The number of overdose deaths involving any opioid in 2021, approximately 80,400 [3], exceeds that observed in the peak year of the HIV/AIDS epidemic.

Excessive prescription of opioids is considered one of the most important causes of this crisis. In the United States alone there were 240 million opioid prescriptions dispensed in 2015, nearly one for every adult in the general population [2].

America is not alone: some European countries have now overtaken the USA and become higher consumers of prescribed opioid analgesics, behind Canada [4].

Many lessons regarding the use of opioids in pain management can be drawn from examining the circumstances which led to the pervasive reliance on opioids in the USA.

Evolution of the opioid prescription epidemic in North America

In the early 1980s advances in the palliative care movement led to increased acceptance of the use of opioids in end-of-life care in many countries where their use had previously been severely curtailed. Significantly aided by the introduction of the World Health Organization (WHO) Pain Ladder, this led to significant improvements in the quality of pain management and symptom control in palliative care in many parts of the world [5].

Galvanised by the improvements which took place in care at the end of life as a result of more permissive opioid use, many pain management clinicians and organisations promoted the use of these drugs in non-cancer chronic pain, as well as the principles of titrate-to-effect, open-ended titration and round-the-clock dosing of opioids which had been found to be so effective [6].

As we will explore in this course, the liberal use of opioids and the application of palliative care principles to the management of other forms of non-cancer pain led to a number of societal repercussions which are still very relevant today.

In 1995, the American Pain Society (APS) launched the ‘Pain: the Fifth Vital Sign’ campaign [7]. The APS guidelines advised that pain should be monitored as regularly as the other then commonly used four vital signs and that abnormal scores should act as a prompt to provide analgesia. The use of unidimensional pain scales (ie pain scales which only measure pain intensity, such as visual analogue scales or numerical rating scales) to record and track pain intensity was recommended. This campaign was widely supported by many medical organisations and societies and was also adopted in the UK [8]. As we will see later in the course, the use of unidimensional pain scales and target pains scores has not been shown to lead to improved pain intensity and has been associated with an increased incidence of over-sedation and increased opioid use [8].

Not long after the launch of this campaign, in 1996, Purdue Pharma introduced OxyContin, a modified-release formulation of oxycodone, and promoted this by heavily targeting lawmakers, professional and patient organisations and individual physicians with claims that the drug was safe, efficacious and had a low potential for addiction [9]. There is now ample evidence these claims were not true: persistent opioid use is associated with increased adverse outcomes, is not effective in improving pain intensity or function long-term, and is associated with a significant risk of dependence.

In 2001, the US Joint Commission on Accreditation of Healthcare Organizations (JCAHO) and the US National Pharmaceutical Council published guidance which sustained that “in general, patients in pain do not become addicted to opioids” [7]. A now-infamous letter to the editor in the New England Journal of Medicine, only one-paragraph long and based on a single-centre retrospective database review, was widely used to back these claims, and was cited more than 400 times [10].

It is likely that the specific characteristics of the US healthcare system, its regulatory regime, and its cultural and socio-economic make-up also contributed to making US society vulnerable to indiscriminate opioid prescribing [9]. In particular, the private nature of much healthcare provision in the US is felt by many to have provided a financial incentive to ensure patient satisfaction. Reimbursement of hospitals by Medicare and Medicaid services at the time became tied to quality of care assessments which included questions to patients regarding whether ‘everything possible’ had been done to address their pain [7]. Health-insurance plans often covered pain medication but not the multidisciplinary pain management approaches which are more effective long-term in managing chronic non-cancer pain.

This combination of factors led to a system with no disincentive and multiple perverse incentives to prescribe opioids, often long-term, at a time when social attitudes towards pain had moved to its being perceived as unacceptable and inhumane, with opioids viewed as the gold-standard and compassionate treatment option.

Excessive prescription of opioids is in itself a public health problem. Opioids are not effective analgesics in most patients with long-term (chronic or persistent) pain, and often lead to a poorer quality of life. They are also associated multiple negative health outcomes: they increase the risk of falls, have many negative effects on endocrine function and immunity, produce hypersensitivity of the pain system and increased pain in some patients, and can cause dependence and addiction. Chronic use of opioids is also linked to higher mortality.

The dramatic increase in opioid prescription use, however, was not the only consequence of these changes in practice, as you will see in the next step.

References

_{1. Humphreys K. Avoiding globalisation of the prescription opioid epidemic. Lancet 2017;390:437-9.}

_{2. Addressing Problematic Opioid Use in OECD Countries. OECD Health Policy Studies, Paris (2019).}

_{3. Drug overdose death rates. National Institutes of Health, US Department of Health and Human Services (2023).}

_{4. Ju C, Wei L, Man KKC, et al. Global, regional, and national trends in opioid analgesic consumption from 2015 to 2019: a longitudinal study. Lancet PH 2022;7:e335-46.}

_{5. Sullivan M, Ballantyne JC. The right to pain relief and other deep roots of the opioid epidemic. Oxford: Oxford University Press (2023).}

_{6. Ballantyne JC, Kalso E, Stannard C. WHO analgesic ladder: A good concept gone astray. BMJ 2016;352:i20.}

_{7. Chidgey BA, McGinigle KL, McNaull PP. When a Vital Sign Leads a Country Astray – The Opioid Epidemic. JAMA Surg 2019;154:987-988.}

_{8. Levy N, Sturgess J, Mills P. “Pain as the fifth vital sign” and dependence on the “numerical pain scale” is being abandoned in the US: Why? BJA 2018;120:435-438.}

_{9. Deweerdt S. Tracing the US opioid crisis to its roots. Nature 2019;573:S10-S12.}

_{10. Leung PTM, Macdonald EM, Stanbrook MB, Dhalla IA, Juurlink DN. A 1980 Letter on the Risk of Opioid Addiction. NEJM 2017;376:2194-2195.}