Courtesy of PainEDU Newsletter, Vol.33, No.1.  To visit the Pain EDU website, go to http://www.painedu.org.

June 30, 2003. The undertreatment of chronic pain in general remains a significant public health issue. In particular, even though there has been a plethora of new analgesics, even though there are numerous available non-pharmacologic approaches to pain management, and despite the fact there have been guidelines established for the treatment of chronic pain in the geriatric population, the undertreatment of chronic pain in the elderly persists (J Am Geriatric Soc, 2002). This article will review several key issues not only in the assessment of pain in the elderly but also in the treatment of pain in the elderly.

It is important to recognize that age by itself does not result in impaired pain sensitivity. In addition, age itself does not change the quality of the pain experience for an individual. Pain may be a source of or an exacerbating factor of depression in the elderly. The inability for an older person to perform basic activities of daily living as the result of the pain can be quite disturbing and depressing to the older person with chronic pain. Cognitive impairment in the geriatric population may limit the full assessment of pain as well as impair the ability to fully treat the condition. The elderly are likely to have other diseases/illnesses to contend with, increasing their frailty and at the very least complicating the treatment approaches. As a result, it is especially important when prescribing analgesic medications for elderly patients, that specific attention is paid towards choosing regimens that are least likely to cause organ toxicities, have significant drug-drug interactions or have other adverse effects such as somnolence or ataxia that would severely limit their use and safety in this population (Harkins, 1996).

Osteoarthritis is one of the most common pain disorders in the elderly. Radiographic severity of osteoarthritis of the knee for example correlates well with increased pain, impaired function and psychological dysfunction. The prevalence of knee pain appears to be greater in older women compared with older men. Data from a national survey indicates that the prevalence of musculoskeletal pain affecting the neck, back, hip and knee is greater in older persons (mean age 75) than in younger persons (mean age 40). Of interest is that in this study, even when the prevalence of pain in a particular location was similar in the two groups, the effect of the pain on impairing activities of daily living and in disturbing quality of life was greater in the older group. (National Health Nutrition Survey, 1982-1984). There have been mixed results in studies looking at altered pain thresholds in the elderly compared with younger subjects; some studies have demonstrated lower sensory thresholds and others have demonstrated higher; thus no conclusions can be made.

In one study of chronic pain in elderly nursing home residents, pain was associated with the inability to enjoy social activities in 54%, depression in 32%, impaired cognition in 12% and anxiety of 26% of residents (Teno et al., 2001). A key step in the treatment of pain in the elderly is actually recognizing the pain. The elderly patient may not always volunteer the information and therefore they must be asked routinely whether or not they are experiencing any pain. There are no specific biological markers or blood tests for the measurement of pain; therefore, the clinician must rely on the patient’s self-report as the best objective measure of the pain as well as of its severity (AGS Panel on Chronic Pain in Older Persons, 1998).

The pharmacological treatment of pain in the elderly has some unique aspects to it. No single dose of analgesic is appropriate for all patients with chronic pain. The elderly may metabolize certain medicines more slowly than a younger patient would. It is therefore recommended in general that starting treatment with a low dose of medication and slowly titrating the dose upwards is the best way to achieve satisfactory analgesia and minimize side effects. In general, using the least invasive route of administration and reassessing the patient’s complaint of pain frequently is advisable. The scope of this article does not permit a detailed description of each of the currently available pharmacologic therapies for elderly patients with chronic pain but choices include non-opiate analgesics such as non-steroidal anti-inflammatory agents, Cox 2 specific drugs, antidepressants, anticonvulsants and topical therapies as well as the opiate analgesics.

Non-opioid analgesics including acetaminophen and NSAIDs are commonly used to treat pain in the elderly. While the tolerability of acetaminophen may make it appear to be an ideal choice as an analgesic for mild to moderate pain, long-term use of acetaminophen must be very carefully monitored because of the potential for hepatic and renal toxicities – even with use of the recommended doses. In particular in managing pain in the elderly, care must be taken to maximize benefit and minimize harm; therefore, ideal analgesic choices might include topical therapies such as the lidocaine patch, Cox 2 specific drugs and certain anticonvulsants such as gabapentin. Certain pharmacotherapeutic agents should be avoided in the elderly including NSAIDS with a known predilection for gastrointestinal or renal side effects, antidepressants such as amitriptyline which are known to have significant risk of cardiac toxicity and certain anticonvulsants such as valporic acid and carbamazepine which are known to have adverse hepatic and bone marrow effects.

Opiate analgesics have clearly emerged as an acceptable treatment for chronic non-cancer related pain. Their use should be strongly considered in the elderly as single entity opiates do not have a ceiling effect with respect to organ toxicity and low doses of a variety of opiate analgesics can be extremely helpful in the management of pain in the elderly. Perhaps most important are the avoidance of medications which have come to be recognized as inappropriate in the elderly. These include: meperidine, pentazocine, propoxyphene, indomethacin, cyclobenzaprine, amitriptyline and doxepin (Beers, 1997). The treatment of pain in the elderly poses certain challenges but these can be overcome and effective management can be realized.

References:
American Geriatric Society. The management of chronic pain in older persons. AGS Panel on Chronic Pain in Older Persons. Geriatrics 1998; 53 (suppl 3) s8-s24.
Beers, MH. Explicit criteria for determining potentially inappropriate medication use by the elderly. An update. Arch Intern Med 1997; 157: 1531-1536.
Guidelines for Treatment of Pain in the Elderly. J Am Geriatric Soc 2002 June; 50 (6 Suppl): S205-224