Pain Management For The Elderly

Transcription

1 S45 FOCUSED REVIEW Pharmacologic Approaches to Geriatric Pain Management Joseph E. Burris, MD From the Department of Physical Medicine and Rehabilitation, University of Missouri, Columbia, MO. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors(s) or upon any organization with which the author(s) is/are associated. Reprint request to Joseph E. Burris, Univ of Missouri, DCO46.00, 1 Hospital Dr, Columbia, MO 65212, BurrisJ@health.missouri.edu /04/ $30.00/0 doi: /j.apmr ABSTRACT. Burris JE. Pharmacologic approaches to geriatric pain management. Arch Phys Med Rehabil 2004; 85(Suppl 3):S45-9. This focused review highlights pharmacologic approaches to geriatric pain management. It is part of the study guide on geriatric rehabilitation in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article specifically focuses on agespecific differences in pain assessment and use of medications for pain management in older adults. The common disorders leading to acute and chronic pain conditions in the older adult are also described. The article contains practical recommendations regarding use of acetaminophen, anti-inflammatories, opioids, antiepileptics, antidepressants, and topical counterirritant drugs for pain management in older adults. Overall Article Objective: To summarize pharmacologic approaches to geriatric pain management. Key Words: Aging; Pain; Pharmacology; Rehabilitation by the American Academy of Physical Medicine and Rehabilitation CHRONIC PAIN IS A frequent problem in up to half of the community-dwelling geriatric population, with estimates of up to 80% for the institutionalized elderly. 1-4 Skeletal pain related to osteoarthritis, rheumatoid arthritis, cervical and lumbar spondylosis, osteoporosis, and fractures with resultant deformities, including contractures, may occur. Neuropathic pain related to peripheral neuropathy from diabetes mellitus, previous stroke, and postherpetic neuralgia, as well as pain associated with peripheral vascular and cardiovascular diseases, skin ulcers, and cancer occur with greater frequency in this population. Serious consequences, including depression, insomnia, impaired mobility, delayed healing, and decreased socialization, may contribute to escalating health care costs and interventions. Delirium and dementia may complicate assessment and treatment of painful conditions in elderly persons. The perception of pain occurs via nociception, which is composed of transduction, transmission, modulation, and perception. 1,5 The nociceptive pathways are comprised of 3 components: the peripheral nerves, the spinal cord, and the cerebral system. Pain sensations may be divided into somatic, visceral, neuropathic, sympathetic, and central pain syndromes. Once the brain perceives a noxious stimulus, interpretation for an appropriate response must be determined. Emotional responses to acute pain differ from those associated with chronic pain. Acute pain is a symptom of disease. It is provoked by noxious stimulation generated by tissue injury generally injury accompanied by abnormal function of somatic or visceral structures and is followed by emotional, psychologic, and autonomic responses. Acute pain has a biologic function characterized by alerting, resting, and healing. Chronic pain is a disease itself. It persists beyond the usual course of acute disease and is provoked by chronic pathologic processes and dysfunction of the peripheral and central nervous systems. It is associated with psychologic, environmental, and, often, learned factors. Autonomic responses do not generally occur. Chronic pain does not serve a biologic function. PAIN ASSESSMENT Pain assessment in the elderly is complicated by many factors. 1,2,6,7 Vision and hearing disturbances may lead to inaccurate assessments when formal measurement scales are used. In a person with cognitive impairment caused by stroke, delirium, or dementia, it may be difficult to delineating various distressful external or internal stimuli, which confounds appropriate measurement and treatment of pain. Ageist cultural or societal beliefs, such as pain is inevitable with aging or an elderly person will simply know when they have pain, may present barriers to treatment. Pain assessment instruments for older adults should be simple, readily available to patients and staff, and in large print. They should also describe pain in language that patients may comprehend (table 1). Familiar words such as slight, mild, moderate, severe, or extreme may be preferred over the traditional 1 to 10 rating scale. 8 Pain for nonverbal or profoundly impaired patients should include observations for pain behaviors during movement or palpation of a suspected painful region. Family members may provide information regarding the patient s pain history and may assist with etiology and treatment issues. Poor appetite, Table 1: Pain Assessment Questionnaire for Geriatric Pain Management 1. How severe is your pain right now (none, mild, moderate, severe)? 2. How severe has your worst pain been over the course of the past week, month, and year (none, mild, moderate, severe)? 3. How would you describe your pain right now and over the course of the past week, month, year? 4. What treatments have you found that help relieve your pain (medications, cold pack, hot pack or heating pad, braces, positioning)? How often have you used these treatments in the past day, week, month, year? 5. What symptoms seem to accompany your pain (paresthesias, loss of appetite, loss of sleep, depressed mood, irritability, inability to concentrate)? How often have these symptoms occurred over the course of the past day, week, month, year? 6. How has your pain interfered with your activities of daily living (ADLs) such as eating, grooming, dressing, bathing, and toileting? 7. How has your pain interfered with your ADLs such as cooking, housekeeping, shopping, paying bills, and driving? 8. How has your pain interfered with your ability to participate in activities such as hobbies, travel, and socializing with friends over the course of the past day, week, month, year?

2 S46 PHARMACOLOGIC APPROACHES TO GERIATRIC PAIN MANAGEMENT, Burris Table 2: Pharmacotherapy Recommendations for Pain Management in Elderly Persons Medication Initial Dose Maximum Dose Adjustment Comments Acetaminophen (Tylenol) 650mg PO every 6h 4000mg/24h Monitor liver function, precaution with known or potential liver disease or drug-liver interaction. Nonselective COX inhibitors Ibuprofen (Motrin) 200mg PO every 8h 3200mg/24h Monitor renal and liver function, Salsalate (Disalcid, Salflex) 500mg PO every 3000mg/24h Monitor renal and liver function, Naproxen (Naprosyn, Aleve) 200mg PO every 1500mg/d Monitor renal and liver function, Meloxicam (Mobic) 7.5mg PO daily 15mg/d Monitor renal and liver function, Nabumetone (Relafen) 500mg PO daily 2000mg/d Monitor renal and liver function, COX-2 inhibitors Rofecoxib (Vioxx) 12.5mg PO daily 25mg/d or 50mg/d NTE 5d Higher doses associated with lowerlimb function, Valdecoxib (Bextra) 10mg PO daily 10mg/d None Higher doses associated with lowerlimb function, Celecoxib (Celebrex) 100mg PO daily 400mg/d Higher doses associated with lowerlimb function, Opioids Tramadol (Ultram) codeine (Tylenol #3) Morphine sulfate immediate release Morphine oral (MS Contin) oxycodone (Percocet) hydrocodone (Vicodin) Oxycodone sustained release (OxyContin) Fentanyl (Duragesic) Corticosteroids Prednisone (Deltasone, Sterapred, Sterapred DS) 25mg PO every 6h 300mg/30mg, h 15mg PO every 4h 400mg/24h; 300mg/24h if age 75y Monitor renal and liver function as dose adjustments required for renal and liver disease. May lower seizure threshold. Serotonin syndrome with SSRIs, triptans, and others. Sedation risk. 12 tabs/24h Schedule III drug. Monitor liver NA Schedule III drug. Sedation risk, constipation, 15mg PO every NA Schedule III drug. Sedation risk, constipation, 5mg/325mg (other 12 tabs/24h Schedule II drug. Monitor liver strengths available) h 500mg/5mg (other strengths available) h 10mg PO every 25 g/h patch, topical every 72h 8 tabs/24h Schedule II drug. Monitor liver Generally 160mg/24h 100 g/h patch After 3 6 doses Schedule II drug. Monitor liver Do not crush or chew medication. Schedule II drug. Sedation risk, constipation, Do not cut or alter patch, rotate sites. 5mg PO daily 60mg/d Monitor GI side-effects (consider PPI), glucose intolerance, peripheral edema, behavior changes. Use short-term only if possible.

3 PHARMACOLOGIC APPROACHES TO GERIATRIC PAIN MANAGEMENT, Burris S47 Table 2 (Cont d): Pharmacotherapy Recommendations for Pain Management in Elderly Persons Medication Initial Dose Maximum Dose Adjustment Comments Anticonvulsants Gabapentin (Neurontin) Carbamazepine (Tegretol) Divalproex sodium (Depakote) Phenytoin (Dilantin) Tricyclics Amitriptyline (Elavil, Endep) Nortriptyline (Pamelor, Aventyl HCL) Topicals, other Capsaicin (Zostrix) Lidocaine transdermal (Lidoderm) 100mg PO every 8h 3600mg/24h, slow 100mg PO every 250mg PO every 100mg PO every 10mg PO nightly at bedtime 10mg PO nightly at bedtime.025% cream topical to affected area 3 times daily 5% patch topical to affected area, for up to daily 1600mg/24h 60mg/kg every 24h 1500mg/24h, slow, slow, slow Total daily dosing dependent on creatinine clearance. Seizure risk with abrupt drug withdrawal. suppression (pancytopenia), hyponatremia. suppression (pancytopenia), hyponatremia. Delerium, tremor, and toxic drug levels. suppression (pancytopenia). Delerium, tremor, and ataxia with toxic drug levels. 150mg/d Every 2 3wk Generally not recommended in elderly persons. Anticholinergic side effects. Cardiac conduction risk. 150mg/d Every 2 3wk Anticholinergic side effects. 4 times daily,.075% cream also available 3 patches at 1 time After at least 3 6 applications After at least 3 6 applications Burning, erythema, thermal hyperalgesia. Avoid touching mucous membrane regions until hands are thoroughly washed with soap and water. Test initially on small skin region. May cut to size. Do not apply to broken or inflamed skin. Caution if impaired liver function. May increase risk of cardiac arrhythmias with class I antiarrhythmic drugs. Abbreviations: COX, cyclooxygenase; GI, gastrointestinal; NA, not applicable; NTE, not to exceed; PO, by mouth; PPI, proton pump inhibitor; SSRI, selective serotonin reuptake inhibitors. depression, insomnia, anxiety, agitation, aggression, refusal of care, moans, groans, or crying should be documented as possible evidence of pain. New behavioral problems in dementia patients may reflect a number of uncomfortable situations, including urinary tract infections, constipation, or discomfort from falls or injuries. Treating the person s pain may reduce his/her use of anxiolytics and antipsychotics prescribed for agitation or aggressive behavior in cognitively impaired patients. PAIN TREATMENT RECOMMENDATIONS Pharmacologic Approaches Physiologic changes with aging, including slowed absorption and metabolism, and changes in medications may lead to excess sedation, confusion, constipation, and urinary retention in geriatric patients. 1,2 Judicious use of medications provides balance between relief of elderly patients pain and suffering with avoidance of the potentially life-threatening side effects of many analgesic medications. Whenever possible, the least invasive route of administration of pain medications should be used. Intramuscular medications do not offer specific advantages over oral medications, and absorption of intramuscular medications is less predictable in older patients. Specific medications useful for pain management in the geriatric population are discussed below. Table 2 serves as a quick reference guide for several medications, with dosage recommendations and comments regarding specific medications. Acetaminophen. Acetaminophen is the analgesic of choice to relieve most types of mild to moderate pain. 1,2 Scheduled dosing versus as-needed dosing of this medication improves

4 S48 PHARMACOLOGIC APPROACHES TO GERIATRIC PAIN MANAGEMENT, Burris efficacy for treatment of chronic pain. Total daily doses of 3000 to 4000mg taken every 6 to 8 hours are recommended, with cautions regarding liver disease and drug interactions with medications that are eliminated through liver mechanisms (eg, coumadin). The maximum recommended total daily dose of acetaminophen is 4000mg. Caution should also be advised regarding the presence of acetaminophen in other combination medications, such as narcotic-acetaminophen drugs (eg, Percocet, Vicodin). Such drugs must be accounted for with total acetaminophen daily dosage guidelines. Nonsteroidal anti-inflammatory drugs. Nonsteroidal antiinflammatory drugs (NSAIDs) should be used with caution in geriatric patients, particularly with any documented history of renal insufficiency; peptic ulcer disease; concurrent use of anticoagulant, antiplatelet, or corticosteroid medications; and bleeding diatheses. 1,9-13 Short-acting medications, given in lower dosages, for short-term use, can be considered. Traditional NSAIDs, often referred to as COX-1 and COX-2 NSAIDs, bind reversibly and nonspecifically to cyclooxygenase (COX) isoforms 1 and 2, which limit inflammation in muscular tissues, although, unfortunately, they also limit COX-1 protective activity in the gastric mucosal lining. COX-2 inhibitors avoid this COX-1 inhibitory effect and therefore have reduced gastrointestinal side-effect risk, although renal toxicity, hypertension, and limb edema side effects must continue to be monitored. Misoprostol, a synthetic prostaglandin, reduces risk of peptic ulcer development, though the side effect of diarrhea limits compliance. Proton pump inhibitors reduce the risk of developing peptic ulcer disease and should be considered if patients are placed on NSAIDs. Opioids. Opioid analgesic medications are generally indicated for moderate to severe pain. 1-3,13 Opiates may be titrated for effect and are available in a variety of preparations, such as oral immediate and sustained release, as well as transdermal delivery systems. Pain severity, medical and cognitive status, and side-effect tolerance may guide selection of this class of medications. Episodic moderate to severe pain may be treated with as-needed medications, although continuous pain should be treated with either long-acting or sustained-released preparations. Scheduled doses of short-acting medications should be titrated for desired effect, and then conversion to long-acting formulas may be performed. Morphine equivalency charts allow equianalgesia among various preparations. Side effects such as constipation, sedation, impaired cognition, and urinary retention must be noted and addressed. Neuropathic pain medications. Neuropathic pain is often described with a burning or pins and needles quality and may be associated with uncomfortable numb sensations. 1-4,14-16 Previously nonpainful stimuli, such as light touch to an affected area, may be perceived as painful. Neuropathic pain may occur with intracranial injuries such as stroke or traumatic brain injury (TBI). Resultant hemiparesis may be associated with spasticity, defined as a velocity-dependent increase in muscular resistance with attempted joint movements in the affected limb. The central pain syndrome, formerly known as thalamic or Dejerine-Roussy syndrome, is actually a relatively rare phenomenon producing pain on the stroke-affected side of the body and may occur with strokes outside of the thalamic region. Peripheral neuropathy, most commonly associated with diabetes mellitus, may result in painful conditions. Patients suffering limb amputation may develop phantom limb pain or pain resulting from neuroma formation in the residual limb. Seizure medications. Seizure medications may reduce neuropathic pain after stroke or TBI or with painful peripheral neuropathy. 1-4,14-16 Gabapentin, with its low side-effect profile, is commonly prescribed. Renal clearance reduces interactions with other medications, and monitoring of drug levels and liver function is not necessary. The dosage must be adjusted on the basis of creatinine clearance and must be used with caution in patients who have progressive renal insufficiency. Other seizure medications, such as phenytoin, valproate, and carbamazepine, also may be prescribed for neuropathic pain. Pain reduction at the lowest dosage should be a goal, rather than aiming for drug level ranges used for seizure control in laboratory settings. However, periodic monitoring of drug levels to ensure lack of toxicity or deleterious toxic side effects, as well as monitoring of liver function, is necessary. Tricyclic antidepressants. Tricyclic antidepressants (TCAs) are efficacious in the treatment of pain related to neuropathic conditions. 1-4,14-16 Amitriptyline, nortriptyline, and desipramine may be prescribed at much lower doses than those previously used to treat psychiatric conditions, making drug level monitoring generally unnecessary. TCAs may, however, be associated with significant side effects, including proarrhythmic properties and anticholinergic properties that may lead to cognitive impairment as well as bowel and bladder dysfunction. Topical neuropathic pain medications. Capsaicin cream, which depletes pain fiber nerve terminals of substance P, may be used to treat neuropathic pain. 17 Care must be used to avoid accidental placement of the medication in undesired locations, such as mucous membranes and eyes, which may result in a potentially significant untoward complication. Careful handwashing and careful movement of clothing, bed linens, or dressings over treated regions reduces this risk. Lidocaine patches are approved for treatment of neuropathic pain related to postherpetic neuralgia, and reports of use in other painful conditions have been noted as well The side-effect profile is minimal, with prudent use minimizing any risk of systemic lidocaine absorption and resultant cardiac arrhythmias. Nonpharmacologic Approaches A comprehensive approach to management of painful conditions should include nonpharmacologic methods. 1,2,21 Appropriate referrals to physical and occupational therapists for exercise training and use of therapeutic modalities may significantly reduce pain and improve patient function. Speech therapists may develop strategies for improving cognition and communication, as well as treating dysphagia to improve nutritional status and to ensure safe consumption of oral medications. Psychologists may assess cognitive status, evaluate for the presence of mood disorders, and assist with development of behavioral pain management strategies, all of which may reduce patients pain and suffering. CONCLUSIONS Pain is a common and complex issue for older adults. Achieving the goal of improved patient comfort requires frequent reassessment, use of multiple and complementary approaches, and careful monitoring of medical and functional status. When successful, however, improvement in the quality of life may be achieved with benefits for individual patients as well as for the health care system and society as a whole. References 1. AGS Panel on Persistent Pain in Older Persons. The management of persistent pain in older persons. J Am Geriatr Soc 2002;50: S Gloth FM 3rd. Pain management in older adults: prevention and treatment. J Am Geriatr Soc 2001;49: Ferrell BA. Pain evaluation and management in the nursing home. Ann Intern Med 1995;123:681-7.

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