|Treating Pain in the Elderly Patient
Jayne Pawasauskas, Pharm.D. and Kevin L. Zacharoff, MD
Elderly patients often suffer from both acute and chronic painful conditions. Arthritis and other bone and joint problems are particularly prevalent in the elderly population. Pain from cancer, skin ulcers, diabetes mellitus, and surgical procedures also plague elderly individuals (Cramer et al., 2000). Evidence suggests that up to 60% of elderly patients residing in the community, and up to 80% of those in nursing homes experience considerable pain (Herr, 2001).
Guidelines for managing pain in the elderly have been developed over the years in an effort to promote effective management of pain for this population. The American Geriatrics Society published clinical practice guidelines specifically for the assessment and pharmacologic management of pain in the elderly in 1998 and then released revised guidelines in 2009. In addition, the American Medical Directors Association published guidelines for the management of pain in the long-term care setting (American Medical Directors Association, 1999). The American Pain Society and the American Academy of Pain Medicine also published guidelines for the management of chronic Noncancer with chronic opioid therapy in 2009.
Pain assessment in the elderly may be complicated by several factors. The first of these involves a misconception that pain is a natural or expected consequence of aging. Elderly patients may be reluctant to report pain for a variety of reasons. These may include fear of becoming a nuisance, fear of pain as an indicator of serious disease, and concern for additional expenses, to name a few. Elderly patients may have cognitive or functional impairments that may further hinder the pain assessment process (e.g., delirium, dementia, speech disorders, paraplegias).
Many pain assessment tools that are used in adult patient populations are considered appropriate for use in elderly patients. Numeric rating scales, verbal descriptor scales, faces pain scales, and visual analogue scales are some examples of pain assessment tools that can be used in the elderly.
Elderly patients may have alterations in pharmacokinetic or pharmacodynamic parameters when compared to younger populations. For this reason, there are certain drugs or drug classes that warrant special consideration when used for managing pain in an elderly patient. One of the most common concerns is related to the relative decrease in renal elimination that is seen with increasing age. Calculation of an elderly patientís creatinine clearance will give an estimation of their renal function and help select or adjust medication doses. Some examples of medications that warrant consideration of a patientís renal function when dosing include non-steroidal anti-inflammatory drugs (NSAIDs), morphine, meperidine, and gabapentin. (Meperidine is not considered appropriate for use in the elderly due to potential for accumulation and central nervous system excitability) (American Medical Directors Association, 1999). NSAIDs cause particular concern for the elderly. While they are effective analgesic and anti-inflammatory agents, they can cause significant gastrointestinal (dyspepsia, mucosal erosions, ulcers, perforations, bleeding), and renal (fluid retention, hyperkalemia, decreased renal blood flow, acute renal failure), adverse effects. Many of the potential adverse effects from NSAIDs can be avoided with careful prescribing and monitoring practices. That is, the lowest effective dose and duration of therapy should be used to limit the potential for NSAID-induced adverse effects (AGS, 1998).
When considering metabolism in the elderly, there is evidence demonstrating age-related changes in Phase I hepatic metabolism, whereas Phase II metabolism is relatively unchanged with age (Hardman, 1996). This may be of importance when using a benzodiazepine, for example. A drug such as diazepam that is primarily metabolized by Phase I reactions may accumulate and potentially cause toxicity for an elderly patient. Should a benzodiazepine be needed, selection of a drug such as lorazepam, temazepam, or oxazepam (which are primarily metabolized by Phase II reactions), may be safer choices.
When considering the absorption of analgesic medications in the elderly, questions may arise regarding the use of transdermal fentanyl. Data published on the pharmacokinetics of transdermal fentanyl in the elderly has produced mixed results. One study found higher serum concentrations in elderly patients when compared to younger patients after application of a transdermal fentanyl patch for 24 hours (Holdsworth et al., 1994). Another study found that the time needed for plasma concentrations to double after patch application was greater in elderly patients, although the maximum plasma concentrations reached were similar between the two age groups (Thompson et al., 1998). In general, elderly patients who are prescribed transdermal fentanyl should be closely monitored for any signs of opioid toxicities.
Since elderly patients may be more sensitive to the analgesic properties and side effects of opioids, the use of low initial dosing with slow and careful dose increases is recommended. Development of constipation is always a concern for elderly patients on chronic opioid therapy. Prophylactic bowel regimens should be started whenever opioids are begun. In general, a stimulant-type laxative, with or without a stool softener is often advisable, whereas bulk-forming agents should be avoided in opioid-induced constipation.
AGS Panel on Chronic Pain in Older Persons. The management of chronic pain in older persons. J Am Geriatr Soc 1998;46:635-651.
American Geriatrics Society Panel on the Pharmacological Management of Persistent Pain in Older Persons. Pharmacological Management of Persistent Pain in Older Persons. Journal of the American Geriatrics Society 2009; 57:1331-1346.
American Medical Directors Association. Chronic Pain Management in the Long-Term Care Setting. 1999.
American Pain Society. Guideline for the Management of Pain in Osteoarthritis,
Rheumatoid Arthritis, and Juvenile Chronic Arthritis. 2002.
Chou R, Fanciullo GJ, Fine PG, Adler JA, Ballantyne JC, Davies P, Donovan MI, Fishbain DA, Foley KM, Fudin J, Gilson AM, Kelter A, Mauskop A, O'Connor PG, Passik SD, Pasternak GW, Portenoy RK, Rich BA, Roberts RG, Todd KH, Miaskowski C; American Pain Society-American Academy of Pain Medicine Opioids Guidelines Panel. Clinical guidelines for the use of chronic opioid therapy in chronic noncancer pain. J Pain. 2009 Feb;10(2):113-30.
Cramer GW, Galer BS, Mendelson MA, et al. A drug use evaluation of selected opioid and nonopioid analgesics in the nursing facility setting. J Am Geriatr Soc 2000;48:398-404.
Herr KA, Garand L. Assessment and measurement of pain in older adults. Clin Geriatr Med 2001;17(3):457-475.