Pain Management in the Elderly: Treatment Considerations
The elderly community is at high risk for developing chronic pain conditions. The Institute of Medicine report, Relieving Pain in America, highlighted the increasing prevalence of pain among all age groups but noted that it is consistently greatest among elderly Americans.1 It is estimated that approximately 30% of the elderly population suffers from chronic pain.2 Typically, elderly patients are more likely to report pain in multiple locations, and elderly women are more likely than elderly men to report pain.3 Moreover, these older Americans have the highest rate of long-term consumption of medications for pain.1
Despite being fairly common in the elderly, persistent pain is not an inevitable part of aging. Believing that pain is an expected consequence of aging is one of several common misconceptions that can lead to biased and ineffective management of pain in the elderly. A multitude of other factors pose barriers to effective treatment—these include factors related to patients themselves, to medical professionals, to the health system, and to medications and interventions (Table 1).4
In addition, treatment for pain in the elderly can be complicated by comorbid factors such as cognitive or functional impairments (eg, delirium, dementia, speech impairment, paralysis, etc),5 many of which were discussed in Part 1 of this 2-part series.6 Understanding the special needs of an aging population is an important aspect of pain management for the elderly.
Treatment for chronic pain should follow the biopsychosocial model, a well-known model that encompasses biological, psychological, and social factors that contribute to a person’s illness.7,8 Through this model, practitioners take into account not only a person’s physiologic makeup and genetic history, but also their perceptions about this physiology and the resulting emotional responses, as well as social factors, such as what the culture views as an appropriate response to the illness. This helps clinicians assess illness severity and find the best path to recovery for that person.9
Pain in the elderly is a specialized illness. To properly address treatment, guidelines have been created by many different associations and societies.10-15 These groups recommend a multidisciplinary approach for optimal pain management. Treatment modalities typically are categorized by the following 4 areas of treatment: pharmacotherapy, psychosocial treatment, physical rehabilitation, and interventional modalities.16,17
Pharmacotherapy is the first, and most widely used, treatment modality recommended for geriatric pain. For many patients, pharmacologic therapy is necessary, either for a short time or chronically. There are a number of caveats to remember when using medication to treat pain in this population. Older patients frequently take multiple medications for concomitant medical problems, increasing the risks for adverse effects (AEs) and even mortality from pharmacologic agents. In addition, there are some key dynamics of pharmacotherapy that need to be understood and compensated for as decisions about medication management are undertaken.18 These include the following:
- Older adults have a higher increased body fat and decreased water and muscle mass. This means that water-soluble drugs become more concentrated and have higher initial concentrations, whereas fat-soluble drugs have longer half-lives due to slower release from the body’s fat stores.
- The livers of older patients frequently are smaller and have less blood flow, resulting in a decrease in the number of functioning hepatocytes. This, along with medication effects on the cytochrome P450 system, lead to changes in drug metabolism that need to be carefully monitored and adjusted for in each patient.
- An increase in the incidence of renal disease impacts decisions about medications affected by renal clearance or known to increase the risk for renal damage. Even in the absence of known renal disease, renal clearance can decline significantly in older patients, impacting the AE profile of a number of medications used without problems in younger patients.
Despite the complexity of treating chronic pain in older individuals, the benefits of addressing and treating pain are clear. Chronic pain decreases function, increases the incidence of depression, creates kinesiophobia (fear of movement), and may worsen other chronic diseases that require ongoing management for maximal control, such as diabetes, hypertension, and heart disease.
Persistent pain, especially musculoskeletal pain, can be treated with non-opioids, such as acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs). However, acetaminophen is not appropriate when the patient has liver failure or chronic alcohol abuse or dependence, and patients taking NSAIDs should be monitored for hypertension and other AEs such as gastrointestinal (eg, dyspepsia, mucosal erosions, ulcers, perforations, bleeding) or renal (fluid retention, hyperkalemia, decreased renal blood flow, acute renal failure) effects.
In older patients, it is important to look at topical agents as the safest approach for those who may be on multiple other oral medications or who have comorbidities that may increase the risk for medication AEs or drug interactions.Topical agents can include topical lidocaine, capsaicin cream, topical analgesic agents, or NSAIDs (Table 2).19,20
Lidocaine ointment is an inexpensive option and can be used for patients with neuropathic and arthritic pain. It is easier for many patients to use lidocaine patches, which only need to be applied once per day, compared with the 4-times-daily dosing of lidocaine ointment. Formulary concerns can limit the ability to prescribe patches for some patients. Although the only FDA-approved indication for lidocaine patches is postherpetic neuralgia, recent studies have indicated that lidocaine patches are effective in the treatment of other neuropathic conditions, back pain, and arthritis pain.19,21
Other topical agents, such as capsaicin cream and topical menthol creams, might provide significant pain improvement with minimal risk if there is no allergy to the agents.
Many patients benefit from intermittent NSAID use. Older patients are more sensitive to the nephrotoxic effects of NSAIDs and must be advised to use them only when needed and to remain well hydrated. All NSAIDs worsen hypertension, congestive heart failure (CHF), and renal impairment. NSAIDs are contraindicated in patients with renal disease, those on anticoagulation therapy, and those with CHF. Because many patients take NSAIDs over-the-counter (OTC) (Table 3), every patient needs to be questioned about their OTC medication use.