Issues Magazine

Painkillers: There’s No Such Thing when Pain Persists

By Elizabeth Carrigan

There is a role for opioid medication for all types of severe pain, but the evidence for its use with long-term persistent pain is more uncertain and the side-effects greater.

Pain is an unpleasant sensory experience associated with real or possible harm. Pain is the body’s warning system, designed to get us to take action and repair the body part that hurts.

For simple pain, such as a sprained ankle, taking paracetamol and resting the ankle for a period is usually sufficient. Most people have experienced this type of normal acute pain.

Many people think that pain goes away when an injury heals or disease resolves, and this does happen for a large number of people. However, for one in five Australians the pain does not go away. This is called persistent or chronic pain, because it persists beyond the normal healing time of about three months.

Historically, pain has been considered a symptom of an underlying condition, but medical science now knows that persistent pain can alter nerve pathways so that the nervous system becomes overactive. Normal mechanisms that block or reduce pain stop working, so that persistent pain becomes a disease in its own right.

Often there is no cure for persistent pain. However, it can be managed to a tolerable level.

Pain is complex. As such, its management benefits from a multidisciplinary medical approach. This involves a combination of therapies, and may involve medical procedures and interventions, pharmacology, physical therapies and self-management strategies to reduce pain levels and improve physical function and quality of life.

Impact of Persistent Pain

The impact of pain can be severe and disabling, interfering with daily functions. The pain is felt physically but also impacts personally and socially. Pain can be present without a diagnosis, or occur as a result of injury or surgery. Medical conditions that may lead to persistent pain include musculoskeletal degeneration (osteoarthritis), stroke, diabetes, amputation, spinal cord and nerve injury, cancer and headache/migraine.

Patients often get trapped on a medical merry-go-round as they try to find answers for their ongoing pain. Many tests bring negative results, which often doesn’t bring relief to patients. Many people long for a positive finding, a diagnosis and then a cure. Along this extended journey, an increasing reliance on opioid medication can develop.

Often patients do not get a clear prognosis that persistent pain will be long term until they see a pain specialist and then perhaps have the opportunity to attend a pain management clinic. It is at the tertiary health level where patients learn about the current bio-psychosocial model of pain. Pain can start to occur, even though there is no tissue damage detected, through a neurological process called central sensitisation.

In line with current best practice, there are moves away from treating persistent pain with opioid medication alone. Multi-modal drug therapy, along with non-medical therapies such as paced physical activity and cognitive behaviour therapy, is far more effective.

When people living with pain engage in activities that are important to them, they feel the pain less. Parts of the brain that have been inhibited by the constant pain can become active. An alternative is reducing activity in parts of the brain that create the pain output (neuromatrix change), and activating pain-controlling centres (descending inhibition).

Although the central nervous system can change and become “stuck on pain”, it is possible to retrain it by recruiting mechanisms that reactivate the inhibitory action of nearby brain cells.

Multidisciplinary Pain Management

Over time, the goals of hospital pain clinics have shifted in recognition of the complexity of persistent pain. Historically, pain reduction was considered paramount. Now, however, there is increasing focus on improving activity levels, reducing psychological distress and raising functional capacity.

The multidisciplinary approach involves a team of health professionals working collaboratively to coordinate health care from a number of disciplines, including physiotherapy, psychology and occupational therapy. Eliminating or reducing reliance upon use of opioid medications will often be a priority.

However, the mean waiting time for public pain management clinics is about six months, and can often be more than a year for non-urgent cases. There are patients who have been assessed as non-urgent, with some having to wait three to five years. This excess waiting time can lead to chronicity, disability and opioid use.

Persistent pain is undoubtedly a serious chronic condition that requires the same holistic multidisciplinary management as other long-term conditions such as diabetes. Unfortunately, only 20% of Australians have access to evidence-based pain management and many GPs feel they have no options other than prescribing analgesics.

Opioid Medication

Opioids are a group of analgesics that bind to receptors in the brain and elsewhere. These receptors exist throughout the central and peripheral nervous systems. Opioids are typically prescribed to reduce pain. Complete relief of persistent pain is unlikely to be achieved, and the current rationale is usually to provide a “window” to help the patient rehabilitate and gain function in the short- to medium term.

Long-term opioid use is often associated with side-effects such as constipation, headaches, nausea, dizziness and vomiting. Sometimes these side-effects can be mitigated. Respiratory depression, which can lead to mortality, is a serious complication of opioids and can be exacerbated by increasing doses or by combining alcohol and other drugs with opioid medication.

Longer-term effects of opioids are associated with impaired endocrine systems. These effects can lead to cessation of menstruation, reduced libido, infertility and depression in women, and erectile dysfunction and reduced libido in men. Human studies have demonstrated that opioids can suppress the immune response, reducing the body’s resistance to infection.

Long-term opioid use is also associated with abnormal pain sensitivity. The patient may present with increased pain that is qualitatively different to their previous pain, and the pain may be more widespread.

Opioid Supply and Opioid Poisoning

The Australian Pain Management Association telephone helpline service, Pain Link (1300 340 357), is receiving increasing numbers of calls from people having problems with prescribed opioids. These range from tolerance difficulties to dependence, as well as a minority of callers with addiction characterised by drug-seeking behaviour.

The increasing availability of opioid medication in Australia has led to verified increased harms, overdoses and a thriving black market. A massive increase in the supply of opioids has occurred between 1991 and 2010; the increased availability is resulting from changed prescribing habits. In Australia, the supply of oxycodone increased from 95.1 kg in 1999 to 1270.7 kg in 2008, a thirteen-fold increase.

In 1998–1999, pharmaceutical opioids accounted for 33% of opioid poisonings, but by 2007–2008 had grown to 80%. From 2009 to 2010 in Australia, deaths related to prescribed opioid medications increased by 15%.

Hospitalisations from misuse of opioids are now more common from unintended misuse than from illicit drug-taking. This is despite evidence that reliance on medication alone for persistent pain is unlikely to improve function and quality of life, and there is a need for coordinated health care and holistic treatment of persistent pain.

This is a difficult issue for patients and doctors because opioids are a major weapon in the pain management armoury and need to be available for appropriate use in pain management, particularly acute pain. The use of opioids in treating post-surgical pain and cancer pain is relatively uncontroversial and has a long and well-understood role. However, the use for persistent pain is much less clear with regard to long-term effectiveness and safety. There remain strong doubts about the efficacy of opioids for functional improvements in people with persistent pain over the long term. Given the complexity of persistent pain, it is a wonder that a single opioid works at all.

Developments and Implications

Australia’s Pharmaceutical Drug Misuse Strategy (2012–2015), A Matter of Balance, addresses addiction to prescription medicines (both unintentional as a result of legitimate prescription and illicit use of prescription medicines). The strategy acknowledges that persistent pain is a complex phenomenon that needs to be understood by healthcare professionals if inappropriate prescribing is to be avoided.

The strategy recognises that data relating to the extent of sub-optimal prescribing practice, and to the number of patients who unintentionally misuse these medications, is lacking. The discussion paper prepared before the strategy suggests that these “hidden” problems are likely to be large.

The Pain Link helpline takes many calls from individuals who are prescribed very high daily doses of opioids. Such individuals are often from regional and rural areas. They ring because they are no longer getting the benefit from the medication. Many callers are fearful their doctor might take the medication away. Even if the medication is of little benefit, they often assume that anything is better than nothing.

For these patients, the benefits derived from opioids are minimal. More effective treatment options such as multidisciplinary pain services may not be accessible, or at least not on a timely or affordable basis.

A minority may also be misusing medications, obtaining and using large quantities by visiting a range of prescribers and pharmacists (prescription shopping). This presents challenges for prescribers who may not have much information about their patients, and the problem is passed on to pharmacists to deal with.

What Can Be Done

Coordinated care between hospitals, GPs, nurse practitioners and community pharmacists is important for patients so that discharge summaries include the timing and frequency of diminishing doses of opioid medications as healing and rehabilitation occurs. This can result in the decreased (and discontinued) use of discharge medications such as opioids.

Similarly, early intervention for persistent pain patients is necessary so that patients are more likely to accept at an earlier stage that a range of non-drug therapies may be used for persistent pain and have confidence that the evidence is there for them to work.

The federal government has agreed to a real-time prescription monitoring system to help doctors see a patient’s prescription history to curb “doctor shopping”. This initiative is a positive for people with persistent pain because it has the potential for doctors to discriminate between those patients who need opioids to bring their pain to tolerable levels and those who misuse medication.

A range of non-pharmacological evidence-based treatments for persistent pain should be rebateable through Medicare at the primary care level to improve access to holistic pain management. Changes to Medicare payments to primary health practitioners should facilitate longer consultations for complex pain needs. This would make it easier for GPs to conduct comprehensive assessments, to manage patients with complex pain needs in relation to medicine use, and to coordinate multidisciplinary care across healthcare settings

GPs now have an accredited online learning program available through a joint initiative between the Faculty of Pain Medicine and the Royal College of General Practitioners. It gives them access to the latest evidence-based research and skills to help patients at risk of developing chronic pain, and allows them to develop practical skills to deliver effective pain management to their patients. Currently 80% of people with persistent pain are not receiving the best practice treatment that could improve their health and quality of life.

More pain specialists and pain management specialist services would shorten the waiting periods for patients to access specialist pain clinics, particularly in the public health system. Likewise, patients experiencing difficulties with prescription drug use need better access to detoxification and rehabilitation services.

In terms of public health, a public awareness campaign about persistent pain as a chronic condition could help change misconceptions, including that pain is always a symptom of an underlying pathology and that a visit to the doctor should result in a prescription for a pill. It needs to be understood that long-term pain can change the central nervous system, resulting in a complex pain condition that is difficult to treat. Access to multidisciplinary pain clinics can improve function and quality of life.

The Prescription Opioid Policy, published by the Royal Australasian College of Physicians in 2009, provides guidance on good practice related to opioids for persistent pain. The main message of the policy is that opioids may be prescribed for persistent pain, in a cautious manner, to reduce pain to an acceptable level.

However, medication should always be used alongside non-pharmacological persistent pain management. The Australian Pain Management Association strongly endorses this approach, and works tirelessly to spread and support this message.