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12 Articles in Volume 9, Issue #1
Atypical Herpetic Reactivation and Chronic Pediatric Pain
Blending Prescription Pain Treatments with Alternative Medicine
Cervical Disc Disease with Referred Pain to TMJ
Deep Cervical Muscle Dysfunction and Head/Neck/Face Pain–Part 1
In My Opinion
Laser Therapy: Treating Shoulder Pain in Hemiplegic and Spinal Cord Injured Patients
Pain Management in the Elderly
Personality Disorders in Migraineurs
Surgical Implants for Pain Management
Treating Shoulder Pain in Hemiplegic and Spinal Cord Injured Patients
Trigger Point Ablation and TMJ Syndrome
What a Decade of the Mind Affords the Decade of Pain Control and Research

Pain Management in the Elderly

Structured methods help identify and assess pain in older adults while appropriate analgesic selection and dosing can reduce adverse drug reactions.

The elderly person with pain poses many challenges for the clinician. In this review article, Dr. Elliott articulates practical assessment and therapeutic strategies that will assist the clinician in managing this special population.

Charles D. Ponte, PharmD, CDE, BCPS, FASHP, FCCP, FAPhA

As with any aspect of providing care for older adults, the management of pain can be far from straightforward. Although many people over the age of 65 perceive pain, report pain, and respond to interventions the same way that younger patients do, many others do not.

The purpose of this article is to highlight some areas of pain management that may be problematic in older populations and offer some suggestions for addressing them.

Epidemiology of Pain in Older Populations

Persistent pain is a common finding in older populations. Depending on the method used and population studied, the prevalence of pain has been reported to be from 18 to 88% among individuals over the age of 65 years.1,2Among those individuals with persistent pain, 45% to 80% report that it is undertreated.2

Regardless of its incidence, persistent pain can have important consequences for the patient. Outcomes of persistent, uncontrolled pain include loss of physical function, sleeplessness, disruption of attention, and depression.1 Patients lose function because of avoidance of activities that aggravate the painful area. However, chronic pain can also result in depressive symptoms which may lead to further loss of motivation and interest in activity. Inactivity and self-neglect can lead, in part, to a descending spiral into frailty and death.3 Consequently, it is critical to indentify persistent pain in older adults and make all reasonable efforts to control it.

Prescription Drug Abuse and Addiction

The diversion of prescription drugs for illicit purposes is often a consideration when managing patients with chronic pain. Although prescription drug abuse may be less common in older patients, it still occurs and may be more likely among those with multiple chronic medical conditions.4,5 Steps that are normally taken to ensure that opioids and other controlled substances are being used for their intended purposes should also be considered when managing patients over 65.

In addition to concerns that health professionals might have regarding prescription drug dependence or abuse, many older adults have similar concerns. As a result, some patients fail to request treatment or fail to use prescribed treatment because of a fear of drug dependence or addiction.5 Health professionals need to both use normal surveillance to detect controlled substance abuse as well as to identify situations where patients need reassurance to allay inappropriate fears regarding the risk of addiction.

Assessment of Pain

Readers of this journal are very likely to be familiar with pain assessment and probably assess older adults and their pain on a regular basis. However, it may be worth emphasizing a few things that have been discovered in studies of pain management of older adults. Elderly patients with persistent pain may deny experiencing pain.2,6,7 They may instead use such words as aching, discomfort, or hurting. Many older adults may neglect disclosing painful conditions because they believe that it is a normal result of aging or that nothing can be done to manage it. Given the high prevalence of pain in older populations, health professionals should regularly inquire about pain rather than waiting for the patient to mention it. Such an approach is consistent with the Joint Commission’s consideration of pain as a fifth vital sign.8 Pain should be assessed and monitored on a regular basis in all older patients.

As with other patients, it is critical that the pain must be assessed by its nature and potential cause. Is the pain musculoskeletal or visceral in nature? If so, then analgesics may be very effective. On the other hand, is the pain neuropathic in nature or does it have a neuropathic component? If so then, adjuvant therapy such as tricyclic antidepressants or anticonvulsants may be helpful.

Pain assessment is more complicated in patients with impaired cognition due to dementia and/or delirium. All patients, including those with dementia, should be first asked regarding their perception of pain before relying on caregiver input.9 Patients with mild to moderate dementia are usually able to communicate verbally and can describe their pain, particularly when the health worker focuses on the present. As dementia worsens, a patient’s recall of pain in the past hours or days becomes less reliable and input from a family member or professional caregiver may be necessary to complete a pain assessment. Patients with severe dementia or those with delirium may not be able to express themselves verbally so that other cues of pain need to be considered. Behaviors that may indicate the presence of pain in a patient unable to communicate verbally include: facial expressions, vocalizations, body movements, changes in interpersonal interactions (e.g. increased aggression), changes in routines (e.g. refusing food), and mental status changes.2 An important aspect of assessing pain in a patient who has limited ability to communicate is the institution of a trial of an analgesic (see Figure 1 for an algorithm for Pain assessment in older adults with severe cognitive impairment).

* Examples: grimacing, guarding, combativeness, groaning with movement; resisting care ** Examples: agitation, fidgeting, sleep disturbance, diminished appetite, irritability, reclusiveness, disruptive behavior, rigidity, rapid blinking † Examples: toileting, thirst, hunger, visual or hearing impairment Sources: American Geriatrics Society. The management of persistent pain in older persons. J Amer Geriatr Soc 2002; 50(6, Suppl): S205–S240; andWeiner D, Herr K, Rudy T, eds. Persistent Pain in Older Adults: An Interdisciplinary Guide for Treatment, 2002, Copyright Springer Publishing Company, Inc., New York 10036.

Figure 1. Pain assessment in older adults with severe cognitive impairment. From: Reuben DB, Herr KA, Pacala JT, et al. Geriatrics At Your Fingertips. 2008-2009, 10th Edition. New York. The American Geriatrics Society. 2008. Reprinted with permission.

“Reduced liver and kidney function due to chronic diseases is common and result in altered drug pharmacodynamics and pharmacokinetics.”10

An important component of assessment includes an evaluation of the medication process in a patient being treated for pain. How are the analgesics being administered? Does the patient with persistent pain have separate orders for receiving an analgesic on a regular schedule in addition to as needed? How often is the patient receiving an as needed medication? Are the products being administered properly? Are there any problems with acquiring the products? Can the patient or their family afford the therapy that has been ordered? Most older adults have fixed incomes and many rely on a Medicare Part D prescription drug plan to assist with their medication-related expenses. Analgesics that are not available generically increase the patient’s out-of-pocket expenses as a result of higher co-pays. More costly products also accelerate a patient’s entry into their Medicare Part D plan’s coverage gap or “donut hole.”

Special Considerations in Drug Therapy

The general approach to regimen design in older adults is the same as in younger patients. However, there are a couple of issues that should be noted. Older adults are less predictable in their reaction to medications than younger patients for a number of reasons. Reduced liver and kidney function due to chronic diseases is common and result in altered drug pharmacodynamics and pharmacokinetics.10 Consequently, each older patient’s hepatic and renal function needs to be assessed before starting any new treatment. Most older patients are also receiving other medications so that potential drug interactions need to be assessed in each patient. Most older patients also have one or more chronic conditions that may influence their response to any new treatment for pain. And finally, any older adult with known or subclinical cognitive impairment will be more susceptible to CNS impairment caused by drugs with sedative or anticholinergic properties and so the use of such drugs needs to be minimized, if possible, or their effects carefully assessed when treatment is initiated.

Acetaminophen

Little is known of the changes in analgesic pharmacokinetics and pharmacodynamics that occur as a result of healthy aging. Detailed studies of pharmacokinetics and pharmacodynamics are difficult to conduct in older patients and have not been done for most drugs. For example, consider the most commonly used analgesic of all, acetaminophen. The recommended daily maximum dose of acetaminophen is 4000mg for adult patients with no known hepatic or renal impairment and no history of alcohol abuse.2 No specific studies have been done to determine if this maximum dose is safe or unsafe in older adults. Despite a lack of evidence, some authors empirically recommended lowering the maximum daily dose to levels such as 2600mg. Another approach might be to monitor hepatic function in any patient receiving daily doses of acetaminophen on a chronic basis. A patient whose pain is inadequately controlled and has no underlying hepatic or renal disease could have their daily dose increased to 4000mg per day prior to adding another analgesic. No patient should receive more than 4000mg per day on a chronic basis. Since acetaminophen is contained in many drug products, healthcare professionals need to take a careful inventory of all of a patient’s prescription and nonprescription products when estimating daily exposure to acetaminophen.

Propoxyphene

Some controlled trials have indicated that propoxyphene is no more effective than acetaminophen and yet it may have a greater risk of toxicity.2 Propoxyphene has been included on the Beers’ list of drugs that are potentially inappropriate for use in older patients since it was first published in 1991.11,12 However, products containing both propoxyphene and acetaminophen (e.g. Darvocet®) are among the most commonly prescribed analgesics for older adults with moderate pain. Perhaps a reasonable strategy is to listen to the patient and carefully monitor the effects of therapy. Prior to using propoxyphene, consider instituting an adequate trial of scheduled doses of acetaminophen up to 4000mg per day. If that is not entirely effective, propoxyphene could be added prior to progressing to a nonsteroidal anti-inflammatory drug (NSAID; e.g. ibuprofen) or a product containing a more effective opioid (e.g. hydrocodone). Propoxyphene should be discontinued if pain relief is less than desired.

Nonsteroidal Anti-Inflammatory Drugs vs Opioids

Older patients may not tolerate NSAIDs because of gastric irritation or adverse effects on renal function. Patients with persistent pain who are considered to be poor candidates for an NSAID should receive a product containing an opioid if they require more analgesia than can be provided by acetaminophen or acetaminophen with propoxyphene.2 Most opioid analgesics can be considered for use in older patients with some important exceptions. Meperidene is a poor choice for any patient requiring an analgesic, particularly the elderly. It has a duration of action of only about three hours and its metabolite, normeperidine, accumulates in patients with renal impairment. Drugs that have actions as partial agonists, or mixed agonists-antagonists with activity at the kappa opioids receptor, should be avoided in the elderly because of an increased risk of cognitive impairment and dysphoria.13 Drugs with these effects include butorphanol (Stadol®), nalbuphine, and pentazocine (Talwin®). Methadone is a special case. It is a very effective analgesic that also has efficacy in managing neuropathic pain. Its duration of action is prolonged in many patients allowing convenient dosing regimens. However, methadone is very difficult to dose due to its unpredictable pharmacokinetics and myriad of drug interactions. Most authorities recommend that only physicians with substantial experience with the drug should prescribe it as an analgesic.2,7

Drug Selection for Neuropathic Pain

A wide range of drugs are commonly used in the management of neuropathic pain and are mostly either antidepressants or anticonvulsants. Amitriptyline is the most commonly used tricyclic antidepressant used for neuropathic pain. Unfortunately, it is often poorly tolerated in older adults because of its sedative and anticholinergic effects. Nortriptyline is a tricylic antidepressant that should be considered in place of amitriptyline for older adults. Nortriptyline is less likely to product adverse effects in older adults and has been demonstrated to be effective in treating neuropathic pain.14

Anticonvulsants are also commonly used in the management of neuropathic pain. Clonazepam has been categorized as an anticonvulsant for use in pain management by the American Geriatrics Society persistent pain guidelines.2 However, clonazepam is actually a long-acting benzodiazepine and shares the same risk of producing confusion and sedation in older adults as do other long-acting benzodiazepines such as diazepam.15 In the United States, gabapentin is probably the first drug that is most commonly started for a patient with a painful neuropathy. A closely related drug is pregabalin. These two drugs are fairly similar with respect to efficacy and adverse effects. Pregabalin is different from gabapentin primarily in the pharmacokinetics of its absorption and elimination.14 With pregabalin, increases in oral doses result in similar increases in serum concentrations of the drug. Pregabalin is also less dependent on renal elimination of the unchanged drug so dosing is simpler in patients with renal impairment. However, pregabalin is not available generically, is much more expensive, and is often not a preferred drug by prescription drug plans. Therefore, for most patients, gabapentin would seem to be a better choice as initial therapy.

Topical Analgesics

The topical route of administration of analgesics should also be considered when managing pain in older adults. Topical administration needs to be distinguished from transdermal delivery. A drug that is delivered transdermally is administered on the skin with the intent that the drug will be absorbed to produce a systemic effect.16 Examples of transdermal delivery include fentanyl and nitroglycerin patches. Topically-administered products, on the other hand, are applied to the skin to produce a local effect. Although some systemic absorption occurs, the intent of the therapy is to minimize systemic effects while producing a localized response. Topically administered analgesics are most likely to be effective if pain is isolated to one or a few areas such as a joint or individual nerve distribution. Some products are commercially available while others are compounded by some pharmacies as topical gels. A lidocaine patch (e.g. Lidoderm®) may be very effective in assisting with control of localized neuropathic pain and it is often better tolerated than orally administered anticonvulsants or antidepressants. Topical formulations of antidepressants have also been used to manage neuropathic pain and, although none are available commercially in the United States, they are available from some compounding pharmacies. Topical formulations of NSAIDs have been used more frequently in other countries and may be useful for localized pain due to inflammation such as osteoarthritis. Diclofenac is commercially available in the United States as a topical patch that is administered twice daily. Ketoprofen is an NSAID that has been used topically in other countries and is also available in a gel formulation from compounding pharmacies in the U.S.

Conclusion

Healthcare professionals can improve the function of older adults and their quality of life by using structured methods to identify and assess pain in each older patient that they see in their professional setting. Also, keeping in mind a few considerations in analgesic selection and dosing can reduce the chance that an older patient will experience adverse outcomes as a result of drugs used to manage pain.

Last updated on: December 20, 2011
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