Pain in older adults is often undertreated, leading to serious effects on physical and psychological functioning and overall quality of life. Studies have shown older adults, particularly older adults who are cognitively impaired, receive significantly less analgesic medication than younger cognitively intact cohorts (Bernabei et al., 1998; Feldt, Ryden, & Miles, 1998; Honari et al., 1997; Kaasalainen et al., 1998). Although empirical study documenting the most effective approaches and techniques is still in its infancy with this population, recommendations are available to guide intervention in the management of chronic pain in this often-neglected population.
Management of chronic pain in the older adult is a challenging process; however, treatment approaches that are tailored to the uniqueness of each individual patient and include a multimodal treatment approach can be very effective (Gibson, Farrell, Katz, & Helme, 1996; Luskin et al., 2000). A multidisciplinary approach to pain treatment of the older adult often is also necessary to address the various aspects of the pain experience. The overall goal of pain management is to maximize the older adult's function and quality of life. Although most pain management in older patients is pharmacological, nonpharmacoIogical or non-drug therapies should be used in conjunction with pharmacological strategies whenever possible.
Because the focus of this article is primarily on pharmacological approaches to pain management, the reader is referred to other reviews for a more complete discussion of nondrug methods (DePalma & Weisse, 1997; Mobily, 1994; Patt, 1992; Urba, 1996). Some of these approaches may require modification to address specific cautions and concerns in older patients.
In general, there are two classes of nonpharmacological interventions: physical pain relief approaches, such as transcutaneous electrical nerve stimulation, application of heat and cold, and massage therapy; and cognitive-behavioral approaches, which are aimed at altering the patient's perception of pain and improving coping strategies (Herr & Mobily, 1996; Keefe, Beaupré, Weiner, & Siegler, 1996). Cognitive-behavioral approaches include techniques such as relaxation and distraction therapy, guided imagery, hypnosis, and biofeedback. Use of nonpharmacological approaches can, in combination with analgesics, result in more effective pain management and less dependence on medications (Ferrell, Grant, Padilla, Vemuri & Rhiner, 1991; Hofmann, Farnon, Javed, & Posner, 1998; Mobily, 1994; Tait, 1993).
Educating older adults, and often their caregivers, on the techniques to manage pain is an important intervention, regardless of the approach to pain management. Although many health care providers perceive older adults as unwilling to use nondrug interventions, studies reveal they are actually very responsive to many of these interventions (Middaugh, Levin, Kee, Barchiesi, & Roberts, 1988; Sorkin, Rudy, Hanlon, Turk, Si Steig, 1990). However, there are individual differences in the acceptance and ability to use nonpharmacologic interventions. For example, relaxation and imagery techniques require high levels of cognitive function to be used effectively, thus they may not be a good choice for older adults who are cognitively impaired. Physical and mental fatigue may interfere with some techniques, such as distraction and relaxation. Other factors to be considered when selecting nondrug interventions include the pathophysiologic basis of the pain, functional status, social and financial support, existing coping strategies, and the older adult's preference for selected interventions. The older adult's use of home and folk remedies should be evaluated and supported, unless contraindicated.
ANALGESIC USE IN OLDER ADULTS
The use of analgesics in older adults is common treatment for pain and can be safe and effective (American Geriatrics Society, [AGS] 1998). Although the American Pain Society has documented the appropriateness of opioid use in treating chronic pain, opioids are likely underused in older adults (Popp & Portenoy, 1996). Evaluating the benefits and risks of analgesic use is an important step in selecting appropriate analgesic treatments for older adults.
Selecting the appropriate medication for use with older patients is often complicated by multiple illnesses and multiple medications. The potential is high for drug-drug and drug-disease interactions, and the health care professional must bear this in mind when choosing an analgesic or assessing its effectiveness or side effects (AGS, 1998; Ferrell, 1996; Stein, 1996). Polypharmacy in older patients may increase the risk of adverse effects, and a complete medication history is necessary to assess effectiveness of current medications and prevent drug interactions.
Many drugs may also be subject to altered pharmacokinetics because of decreased renal and hepatic function in older patients (Herr & Mobily, 1997; Lavand'Homme & De Kock, 1998; Stein, 1996). Dosing requires careful títration, including frequent assessment and dosage adjustments to promote optimal pain relief (AGS, 1998).
Several key recommendations in analgesic use for chronic pain in older adults include (AGS, 1998; Ferrell, 1991; Stein, 1996):
* Use of the least invasive route of administration.
* Use of short-acting analgesic drugs for episodic pain.
* Use of around-the-clock administration for continuous pain.
* Use of long-acting or sustained-release analgesic preparations for continuous pain only.
* Dosing carefully, "starting low and titrating slow."
* Anticipation, prevention, and treatment of adverse effects.
An aspect of analgesic pharmacotherapy, which is often overlooked, is a discussion with the patient and family of the desired clinical end points. Determinants of analgesic efficacy, in addition to decreases in the patient's pain, include improvements in function and quality of life issues, such as sleep and mood (AGS, 1998). The following discussion will highlight considerations in the use of selected opioids and nonopiods with the older adult.
SELECTED ANALGESICS FOR THE MANAGEMENT OF CHRONIC PAIN
Acetaminophen and Nonsteroidal Anti-inflammatory Drugs (NSAIDs)
In accordance with current pain management guidelines, acetaminophen and NSAIDs are most often used for mild to moderate chronic pain (AGS, 1998). In designing treatment regimens and balancing side effects, it is important to note that treatment of chronic (as opposed to acute) pain with acetaminophen and NSAIDs may require higher dosing during an extended period (Schnitzer, 1998). The difference between the therapeutic dose and the toxic dose of these medications, as well as of opioids, is smaller in older adults, requiring more judicious assessment and monitoring.
When choosing between an NSAID and acetaminophen, the underlying physiological mechanisms (i.e., inflammatory, noninflammatory) should be considered. For most patients with mild to moderate pain from noninflammatory musculoskeletal conditions, acetaminophen provides effective pain relief with lower risk of side effects (AGS, 1998). The NSAIDs are best indicated for the treatment of inflammatory conditions (Luggen, 1998; Popp & Portenoy, 1996; Schnitzer, 1998), and are therefore frequently used for the management of arthritis in older patients. However, their use may be complicated by an increased risk of gastric and renal toxicity (Leland, 1999; Popp & Portenoy, 1996; Roth, 1989).
In older patients, NSAIDs may also have other significant side effects and are very often the cause of adverse drug interactions (Leland, 1999; Popp & Portenoy, 1996; Verbeeck, 1 990). More than one NSAID should not be taken, and ceiling dose limitations should be expected because of toxicity at higher doses (AGS, 1998). Any patient with abnormal renal function, a history of peptic ulcer disease, or a bleeding diathesis should not take NSAlDs (AGS, 1998). This is of particular importance because NSAIDinduced gastrointestinal tract ulcers may be asymptomatic, causing potentially life-threatening complications Popp & Portenoy, 1996). In general, the high-dose, long-term use of NSAIDs in older patients should be avoided (AGS, 1998; Leland, 1999). The increased risk of these NSAID-induced side effects necessitates judicious evaluation of gastrointestinal complaints, frequent monitoring for bleeding, and regular screens for blood urea nitrogen and creatinine levels to detect renal insufficiency (Herr Si Mobily, 1997). The advent of new classes of NSAIDs (e.g., cyclooxygenase-2 inhibitors) may provide options that can ameliorate the side effect concerns of the NSAIDs while providing effective analgesia (Kaplan-Machlis & Klostermeyer, 1999).
The short-acting opioids are most often administered as oral preparations and occasionally in intravenous or suppository form. Morphine, hydromorphone, oxycodone, hydrocodone, and fentanyl are choices for the management of moderate to severe chronic pain in older patients (AGS, 1998; Dellasega Si Keiser, 1997). Codeine and oxycodone are often used in combination with acetaminophen or aspirin for the treatment of moderate pain and may be the drugs of choice for the transition to opioids from other analgesics (Dellasega & Keiser, 1997). It should be noted, however, that combinations with codeine, hydrocodone, or oxycodone may be dose-limiting because of the toxicity at high doses of acetaminophen or NSAIDs (AGS, 1998).
A newly approved short-acting opioid, oral transmucosaJ fentanyl citrate, formulated as a raspberry-flavored lozenge on a stick, is an option for the treatment of breakthrough pain with onset in 5 to 10 minutes and a short period of activity (approximately 1 hour) Coluzzi, 1998). This potentially could be of great advantage to provide relief of pain to the older adult for anticipated short-term discomfort from physical or emotional Stressors.
Common side effects of the opioids include constipation, nausea, vomiting, sedation, and possible respiratory depression (Hofmann et al., 1998; Leland, 1999). Constipation is a significant side effect of most opioids, and most older patients are predisposed to this condition because of limited activity and decreased fluid intake (Popp & Portenoy, 1996; Stein, 1996). Management and prophylaxis are therefore a necessity. It is important to begin bowel regimens when opiate therapy is initiated, and increased fluids, lubricating agents, and bowel stimulants may be required (Ferrell et al., 1991a).
Other, more dangerous, side effects such as respiratory depression, can be minimized by careful assessment of each patient's response to the drug, with adjustments in dose or timing of administration if necessary (Herr & Mobily, 1997). Urinary retention, intestinal obstruction, delirium, and cognitive impairment are also side effects of some opioids and may be particularly problematic in older patients. Careful monitoring and prophylactic treatment can reduce the severity of these events if they should occur. Once titration has achieved the required analgesic dose, side effects of most opioids can be minimized (Leland, 1999). Because of the short-acting nature of these medications, risk of accumulation and toxicity in older patients is minimal.
Opioid therapy does present problems for older patients who have gastrointestinal tract disturbances or difficulty taking oral medications. For older patients who cannot use oral medications, other appropriate routes include suppository preparations, transdermal patches, subcutaneous, intravenous and Computerized Ambulatory Drug Delivery (CADD®, Deltec Systems, St. Paul, MN) pumps. Although these options are available, they may not always be amenable to patient or caregiver administration, especially in the home or community setting.
Sustained -Release Opioid Preparations
Sustained-release opioids are effective and convenient for patients and caregivers, permitting aroundthe-clock dosing with reduced frequency compared with conventional morphine tablets (AGS, 1998; Dellasega & Keiser, 1997; Hofmann et al., 1998; Leland, 1999). Long-acting agents may be appropriate for older adults with continuous pain whose opioid dosing has been stabilized with short-acting agents. Regular monitoring for side effects and drug effects continues to be an essential part of analgesic management. Two pharmacological options for prolonged opioid dosing in the management of chronic pain are sustained-release oral preparations and transdermal fentanyl.
Sustained-release morphine has generally the same indication as its short-acting form. Dosing is every 8 to 24 hours, and dosages must be titrated to achieve the required analgesia. Doses of sustained-release morphine must be escalated slowly because of the potential for drug accumulation (AGS, 1998). Patients with difficulties taking oral analgesics also experience problems with sustained-release morphine, because sustained-release forms also cannot be crushed or dissolved for dosing reasons. Side effect profiles are similar to those of other morphine preparations.
Sustained-release oxycodone is another, more recently introduced long-acting opioid option for chronic pain relief (AGS, 1998; Cleary & Carbone, 1997). Dosing is every 8 or 12 hours, and this opioid has similar prescriptions against crushing or dissolving. Long-acting agents may assist with medication compliance, a concern with older adults because of the easier administration regimen.
Transdermal fentanyl, a sustained-release option for chronic pain management providing continuous pain relief for up to 72 hours, does not rely on oral administration. The transdermal system offers some distinct advantages over conventional oral and parenteral opioids because it is noninvasive, is simple to use, and eliminates the need for frequent continuous dosing and complicated drug regimens (Woodroffe & Hays, 1997; Yee & Lopez, 1992). Use of transdermal patches has resulted in less interruption of patients' daily activities and those of their families and caregivers (Ahmedzai & Brooks, 1997). This agent may be particularly appropriate for long-term care facility and home use because it uses a less invasive drug delivery route and is associated with greater patient satisfaction than morphine (Payne et al., 1998; Woodroffe & Hays, 1997).
Clinical studies in distinct patient populations have demonstrated that transdermal fentanyl is safe, well tolerated, and effective for the treatment of various forms of chronic pain (Ahmedzai & Brooks, 1997; Donner, Zenz, Strumpf, & Raber, 1998; Payne et al., 1998; Woodroffe Si Hays, 1997). The side effect profile of transdermal fentanyl is generally similar to other opioids (e.g., constipation, nausea, vomiting). However, a number of studies have reported a decreased incidence of adverse effects, including confusion, drowsiness, and, particularly, constipation (Ahmedzai & Brooks, 1997; Allan et al., 1998; Donner et al., 1998; LoRusso, Hardy, Finîay, Davis, & Hinshaw, 1998; Payne et al, 1998; Woodroffe & Hays, 1997). This favorable side effect profile is especially relevant in older patients. Studies that specifically examine the drug's use in older adults are still needed.
Adverse events, such as respiratory depression, may be a concern during the transition of treatment from short-acting to long-acting opioids (LoRusso et al., 1998). The switch from short-acting opioids to sustained-release morphine or transdermal fentanyl was recently addressed. No significant adverse reactions, such as respiratory depression, were noted with the shift in treatment regimens (LoRusso et al., 1998).
Recommendations for effective use of long-acting opioids, whether sustained- release oral or transdermal fentanyl, include the availability of a short-acting analgesic for breakthrough pain, pain assessment at least every 8 hours, and regular monitoring and managing of side effects (Ferrell, Ferrei!, & Rivera, 1995; Wakefield, Johnson, Kron-Chalupa, & Paulsen, 1998).
Adjuvant medications are not pain medications per se, but they may be used in the course of analgesic therapy. Antidepressants (e.g., amitriptyline) and anticonvulsants (e.g., valproic acid) may enhance analgesic effects in specific disease contexts, such as neuropathic pain, when administered alone or in conjunction with other pain medications (Ferrell et al., 1995; Popp & Portenoy, 1996). Adjuvant medications may be well tolerated in some patients and may allow decreased analgesic dosing (and thereby reduced side effects) when used in combination with other analgesics (Cleary & Carbone, 1997).
Their efficacy can often be unpredictable, however, and side effects are a major concern with their use, especially in older patients (Cleary & Carbone, 1997; Popp & Portenoy, 1996). In particular, tricyclic antidepressants, such as amitriptyline, have potent anticholinergic properties that can further complicate pain management and lead to dangerous side effects in older patients (Ferrell, 1996; Hofmann et al., 1998). These complications, and the risk of drug interactions, support the general rule that caution should be used when prescribing these adjuvant medications in the older adult.
For a list of drugs to be avoided for use in older patients, see the Sidebar on page 31.
Effective pain management in older patients requires careful use of available pharmacological and nonpharmacological pain therapies. Depending on the individual's pain problem and history of analgesic use, pharmacological options for the management of pain in older patients may include acetaminophen, NSAIDs, and both short- and long-acting opioids. For persistent pain problems, a long-acting opioid (e.g., transdermal fentanyl) may provide a more convenient option, especially useful in nursing homes, long-term care facilities, and community settings. Possible opioid side effects must be anticipated and managed, especially in older adults. Treatment regimens must also be tailored to each patient's specific needs and medical condition. Finally, whenever possible, pharmacological and nonpharmacological therapies should be incorporated into a long-term pain management plan, which will allow for both decreased pain and improved quality of life for older patients.
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