It is a common belief that chronic pain is an unavoidable consequence of getting older. Seventy per cent of older adults experience pain due to medical conditions associated with ageing such as stroke, surgical procedures, diabetes, osteoarthritis and cardiovascular disease.
In older people, chronic pain management includes multidisciplinary approaches based on pharmacotherapy, physical and psychological rehabilitation, and interventional approaches.
Pharmacological agents used to treat chronic pain in older adults include NSAIDs, antidepressants, anticonvulsants, cannabinoids, muscle relaxants, naltrexone, memantine and opioids. To improve effectiveness and reduce the risk of side-effects, pharmacological approaches based on targeting multiple pain pathways are often used. Although this approach may allow for synergistic effects, it can contribute to polypharmacy and increased treatment burden, so must therefore be undertaken with caution.
Non-pharmaceutical pain management approaches include interventional therapies, rehabilitation and physical therapy, and psychological interventions.
Interventional therapies such as lumbar facet injections, epidural steroid injections, sacroiliac joint injections, percutaneous vertebral augmentation, and hip and knee joint injections are generally low risk with few adverse effects. Benefits of interventional therapies include a reduced risk of side-effects and a reduced need for larger surgical interventions with higher risk and extended recovery time.
Rehabilitation and physical therapy aim to reverse or improve loss of physiological or anatomical structure or function and to reduce the degree of patient disability due to impairment.
Psychological interventions are primarily aimed at reducing co-morbid anxiety and depression and improving poor coping skills. These interventions also include approaches such as acceptance, commitment therapy and cognitive behavioural therapy. Psychological interventions for the treatment of chronic pain reduce pain and catastrophising beliefs and improve pain self-efficacy, particularly when delivered using group-based approaches.
The role of pharmacists
In chronic pain management, pharmacists are important members of the multidisciplinary team. They are in a position to review and adjust medication dosing, monitor polypharmacy and potential pharmacotherapy side-effects, deliver patient educational programmes, and advise on alternative routes of administration of analgesics based on individual needs.
Polypharmacy is prevalent in older adults, particularly those suffering from chronic pain. Pharmacists have an important role to play in ensuring adequate pain relief while at the same time avoiding medication overuse and reducing polypharmacy.
Pharmacists can also provide appropriate support for the administration of many treatment options such as topical analgesics, particularly for the management of localised and peripheral pain conditions.
It is no surprise that older people are a target population to benefit from topical agents and clinical guidelines recommend their use for localised neuropathic and non-neuropathic pain. Additionally, community pharmacists may be more easily accessible to older patients than hospital-based services and able to act as communication hubs between patients and the wider chronic pain management team.
“Patient beliefs portraying pain as a natural part of ageing that needs to be tolerated contribute to older adult patients not seeking adequate treatment for chronic pain”
Challenges with chronic pain management
It is important to note that older adults are under-represented in most clinical trials, meaning the safety and efficacy of medicines approved for the elderly may be less well studied compared to younger adult counterparts. It is also true that advancing age increases the risk of adverse drug reactions and many medicines have a narrower therapeutic index in older adults compared with younger patients.
Both pharmacokinetic and pharmacodynamic considerations must also be taken into account. Pharmacokinetic changes in the physiology of older adults may affect effectiveness and safety of pharmacotherapy. These include variability in volume of distribution depending on medicine lipophilicity, decreased medicine absorption and heightened therapeutic response to protein-bound medicines due to decreased hepatic metabolism, hypo-albuminemia and decreased renal elimination.
Similarly, pharmacodynamic factors may predispose older adults to increased adverse effects from commonly prescribed medications. This can include changes in the central and peripheral nervous system such as decreased receptor density, pre-existing cognitive deficits and decreased nerve myelination.
Medication for chronic pain can only be effective when taken as indicated. Poor compliance is common, particularly in older adults, and may contribute to inadequate pain management.
Underlying causes leading to poor compliance can include poor physician-patient communication, high medication costs, patient ethnicity, and medicines formulation and dosing. Patient beliefs portraying pain as a natural part
of ageing that needs to be tolerated contribute to older patients not seeking adequate treatment for chronic pain.
To improve compliance, improved patient-healthcare professional communication, education to explain the purpose and side-effect profile of medications, simplification of dosing regimens, reduction of polypharmacy, regularly scheduled follow-up appointments, individualised medication cards, medication reviews and multi-compartment administration aids can all be used.