PAIN CONTROL
| PAIN MANAGEMENT IN THE ELDERLY —Brandon Koretz, MD, Assistant Clinical Professor of Medicine, Division of
Geriatrics, The David Geffen School of Medicine at the University of California, Los Angeles
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| Case scenario: Mrs. Quan, 75 yr of age, presents to emergency department (ED) after experiencing sudden worsening of
chronic back pain after falling; pain managed in past with oxycodone/acetaminophen (Percocet) 1 tablet po q4h prn (<6
doses/wk usually required); after fall, pain unrelieved, even with 2 Percocet tablets q4h; in ED, pain so severe patient unable
to move onto x-ray table for lumbar spine series; ED physician ordered morphine sulfate (MS) 15 mg po Q6h prn
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| Pain assessment: be clear about diagnosis and review it as clinical situation warrants, eg, if changes in quality or location
of pain occur, or changes in response of pain to medication; patient and proxy reports— no objective measures of
pain; what patient says most reliable indicator of extent and severity of pain; factors influencing how patient perceives
and reports pain include comorbid conditions and impairments, eg, cognitive or sensory impairment; proxies (eg, caregivers,
family members) helpful in reporting patient’s pain in qualitative terms; functional status—patient with 10/10 pain
who walks regularly in much better shape than one who has 10/10 pain and cannot get out of bed; patient
expectations—if patients expect pain and ascribe it to aging process, they may not report pain; if patients expect procedure
to be painful, they may not want it; note patient’s satisfaction or dissatisfaction with current level of analgesia; pain
scales—can be numbered scales (eg, 0 to 3; 0 to 10) or gradations of discomfort; helpful for patients with cognitive impairment
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| Age-related physiologic changes: hepatic function—decrease normal in elderly; hepatic blood flow decreased;
phase 1 metabolism decreased; in addition, patient may have cirrhosis or be in low-flow state, eg, left ventricular (LV)
dysfunction; decreased renal metabolism—about two thirds of elderly have decreased renal function; also affected by
certain disease states, eg, diabetes, renal artery stenosis; Cockroft-Gault equation helpful in assessing creatinine clearance
(women have lower creatinine clearance for same serum creatinine); meperidine (Demerol)—can induce seizures in patients
with renal problems; normeperidine (metabolite) responsible for seizures and delirium in patients with renal insufficiency
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| Drug interactions: likelihood of interaction increases with number of drugs used; patient on ≥7 drugs almost guaranteed
interaction problems; drug interactions can impair clearance of drugs and promote toxicity; codeine—pro-drug; patient
with very low cytochrome P450 2D6 isoenzyme levels in liver unable to metabolize codeine; remarks—hand-held
programs for assessing drug interactions helpful; www.drug-interactions.com helpful Web site for physicians
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| Route of administration: consider time to peak effect (drugs given via different routes act at different speeds); time to
peak effect ≈5 min for narcotics given intravenously (IV) and 1 to 2 hr for those given orally; therefore, IV route preferred
for acute pain crisis and least invasive route advised for chronic pain; time to peak effect for rectal and sublingual narcotics
probably closer to IV route; subcutaneous (SQ) and intramuscular (IM) administration routes have variable (unreliable)
absorption
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| Schedule of administration: prn dosing—disliked by speaker; patients with cognitive problems may not be able to
communicate with others about pain; scheduled dosing—effective in reducing total dosage and improving pain scores;
breakthrough dosing—important; dosing adjustments required regularly; adjusting dosing interval—often necessary,
because people metabolize drugs at different rates; end-of-dose pain may occur sooner in those who metabolize rapidly,
while slow metabolizers may have relief longer; critical to know when pain starts to recur (time to adjust dosing interval);
time to maximal effect vs duration—physician should give analgesics as quickly as possible and know how long effects
will last
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| Drug dosing and drug conversion: methadone—while its analgesic half-life ≈2 hr, half-life for prevention of side
effects and withdrawal much longer; avoid use, particularly in frail and elderly patients; comments on Mrs. Quan’s
case—morphine equivalent of 2 tablets of Percocet q4h 90 mg/day, was ineffective; therefore, 60 mg/day of morphine
ordered by ED physician (15 mg q6h) ineffective also; caveat—conversion tables only estimations; when switching
from one opioid to another, reasonable to decrease dose of second agent to allow for incomplete cross-tolerance; dosing
rule in geriatrics—start low, go slow, but titrate to pain relief
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 | Titration: in pain crisis, always use short-acting agents; increase dose by 20% to 50% for moderate pain; consider doubling
dose for severe pain; once patient pain-free, take 24-hr drug totals and convert to long-acting morphine equivalent;
always use short-acting agents for breakthrough doses (good rule to give 10% of 24-hr requirement every hour);
as 24-hr requirements increase, breakthrough dose requirements also increase
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| World Health Organization (WHO) analgesia ladder: step 1 (start with nonopioids, eg, acetaminophen, ibuprofen);
step 2 (give weak opioid or combination agent, eg, acetaminophen with codeine); step 3 (involves use of strong opioid
for severe pain); comments—sometimes necessary to start with strong opioid; adding nonopioids may have
synergistic effects
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| Acetaminophen: for mild to moderate pain; has analgesic ceiling; has favorable side-effect and toxicity profiles; may be
no better than placebo for treating osteoarthritis (OA)
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| Nonsteroidal anti-inflammatory drugs (NSAIDs): have analgesic ceilings; toxicity mainly involves gastrointestinal
(GI) tract and kidneys; drugs for minimizing GI toxicity include proton-pump inhibitors and misoprostol (difficult
to tolerate); cyclooxygenase (COX)-2 inhibitors supposedly less toxic to GI tract than nonspecific COX inhibitors,
but have other problems; future of COX-2 inhibitors unclear, but some patients feel they cannot function without celecoxib
(Celebrex); while indomethacin may be good drug for acute exacerbations of gout, speaker reluctant to use it in
frail patients; salicylates have fairly favorable side-effect profile, but individual dosing required
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| Opioids: no ceiling effect for analgesia; can continue to titrate until pain relieved; side effects all dose related (patients can
adapt to all, except constipation; therefore, bowel regimen required); naloxone (Narcan) indicated only for life-threatening
respiratory depression
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| Issues of addiction: tolerance—characterized by need to use higher doses of drug to achieve same effect; dependence—
develops after prolonged use of drug; uncomfortable effects when drug withdrawn; addiction—pattern of compulsive
use, continued craving, or drug use for purposes other than analgesia
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| Meperidine (Demerol): long-term use associated with falls and delirium; avoid in frail elderly patients
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| Propoxyphene (Darvon): equally analgesic to aspirin, but has potential for dependence; try to avoid use
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| Fentanyl transdermal system (Duragesic): reservoir in subcutaneous space, ie, removing patch does not stop absorption
for 18 to 24 hr; problems with use include long half-life and erratic absorption; avoid in narcotic-naïve patients; difficult
to titrate; use shorter-acting agents for breakthrough pain in patient on patch
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| Speaker’s approach to managing Mrs. Quan: give loading dose of morphine 5 mg IV; continue with 1 mg every
5 min via patient-controlled analgesia (PCA); before discharge, calculate total morphine dose, convert to sustained-released
formulation (perhaps in 30-mg pills), and prescribe morphine immediate release or elixir every 4 hr for breakthrough
pain
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| CANCER PAIN —Barbara A. Murphy, Associate Professor of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University
School of Medicine, Knoxville, Tennessee
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| Initial approach for patient with cancer pain: 1) assess pain severity; 2) look at etiology; 3) determine type of
pain
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| Assessment of pain severity: numeric rating scales generally used (0 to 10); establish outcome measures; ask patient
about 1) current level of pain, 2) average level of pain, 3) worst pain level, and 4) pain relief from medication; outcome
parameter most closely correlated to quality of life and physical functioning is worst pain level
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| Etiology: treatable causes include pathologic fractures, bone metastases, and chest wall problems; emergent causes include
cord compression as manifested by isolated thoracic back pain and brain metastases as manifested by headache
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| Types of pain: nociceptive—most common pain type in cancer patients; subdivided into somatic and visceral; somatic
pain most common subtype, and bone metastases most common cause (NSAIDs helpful in treating); neuropathic—
treatment often requires opioids and adjunctive nonopioids, and sometimes referral to pain specialist; pain syndromes
include postamputation limb pain, postthoracotomy pain, postmastectomy pain, brachial plexopathy (head
and neck tumors), lumbosacral plexopathy (rectal or ovarian or cervical carcinoma), and celiac infiltration (pancreatic
carcinoma)
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| Assessment of cancer patients with pain: other medical problems (eg, inability to detoxify opioids) and psychologic
problems, (eg, depression that can exacerbate pain); physical function; cognitive function, eg, “chemo brain,” short-
term memory deficits and alterations in executive functioning that prevent patients from following instructions; availability
of support services; financial status (ability to pay for opioids); education (ability to read and understand labels and
carry out complicated treatment regimens)
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| Writing prescription: involves writing fixed-dose regimen, calculating breakthrough doses, calculating how to convert
from one opioid to another, dose titration, and understanding issues of substance abuse
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| Basic rules for opioid administration: goal is controlled pain, ie, pain level ≤4 on scale of 0 to 10 using ≤4 breakthrough
doses in 24 hr; escalate dose to point of controlled pain as quickly as possible; no maximum opioid dose exists;
warn patients about side effects (advise them not to stop opioids when problems arise, but to tell physician about them;
accomodation to most side effects occurs over 7 to 10 days, except constipation (prescribe bowel regimen); use oral or
transdermal formulations as long as possible; start with immediate-release (IR) formulations in patients with significant
pain; use medications around-the-clock; fixed dose always based on t½ of agent; base rescue dose interval on time to peak
effect (usually 1-2 hr); avoid prescribing meperidine because of seizure risk
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| Fixed dosing: goal is to maintain opioid levels within therapeutic window; fixed dosing allows for achievement of steady
state; once steady state achieved, make dose modifications in calculated fashion; comment—prn dosing not advised (associated
with more pain and more side effects)
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| Half-lives of commonly used opioids: 3 to 4 hr for immediate- release morphine, oxycodone, and hydrocodone; hydromorphone
(Dilaudid) ≈2 hr; sustained release (SR)—morphine sulfate (MS Contin 8-12 hr, Avinza 24 hr); OxyContin
(SR oxycodone) 8 to 12 hr; fentanyl (Duragesic) 72 hr
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| Writing fixed doses: morphine q4h; MS Contin q12h; Dilaudid q3-4h; Duragesic q72h; OxyContin q12h
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| Writing breakthrough doses: use fast-acting formulations; base dosing intervals on time to peak effect; total dose
10% to 15% of 24-hr total fixed dose; example—breakthrough morphine dose 30 mg po q1-2h for patient on IR morphine
60 mg po q4h (24-hr total 360 mg); if patient has not achieved pain relief with rescue dose in 1 to 2 hr, relief will
not occur; if patient has pain and due for SR opioid, tell him or her to take it, and also take IR breakthrough dose
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| Equi-analgesics: morphine considered bedrock agent; general rule—if patient has controlled pain, but needs to switch
due to toxicity, decrease dosage by 25%; equi-analgesic ratios—morphine to Dilaudid 5:1; morphine to hydrocodone
1:1; morphine to oxycodone 1:1; morphine to Duragesic 2 to 3:1, depending on size of patient
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| Converting from one opioid to another: step 1 (calculate 24-hr fixed-dose total); step 2 (convert, if necessary, to
morphine equivalents); step 3 (calculate 24-hr fixed-dose equivalent of new agent); step 4 (divide 24-hr fixed-dose total
by total number of doses per day); example—to convert patient on morphine 30 mg po q4h to Dilaudid; 24-hr fixed dose
is 180 mg; Dilaudid 5 times more potent than morphine, so 24-hr dose of Dilaudid is 36 mg; Dilaudid dosed q4h, so correct
dose 6 mg po q4h
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| Dose titration: dosage adjustment usually required once patient given initial fixed dose and initial rescue dose; for moderate
pain, increase by 25%; for severe pain, increase by 50% (based on 24-hr total dose (fixed opioid total plus rescue total)
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| Long-acting formulations: use only in controlled pain; determine needs with short-acting opioids, then convert to
long-acting agents; if pain becomes uncontrolled, switch back to short-acting agents
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| Conversion example: patient on maintenance dose of morphine 60 mg po q4h and rescue dose 30 mg—has 1/10
pain, but does not like taking pills; can be switched to MS Contin 180 mg po q12 hr, but still needs IR opioid for rescue
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| Fentanyl (Duragesic) patches: provide better pain relief than morphine; patches come in 25, 50, 75, and 100 µg; consider
for patients who are noncompliant, unable to take oral agents, or have cognitive problems; decrease potential for
substance abuse by patient or family
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| IV narcotics: indicated for pain emergencies, patients unable to take drugs orally, those with very high narcotic needs,
and those vulnerable to toxicity from po use; conversion ratio from pills to IV 3:1; write for continuous infusion, with bolus
for rescue; peak effect of IV narcotics <10 min vs 1 hr for oral form; keep hourly rescue dose equal to hourly infusion
dose; patient satisfied on MS 60 mg po q4h—coming in for surgery and must be npo; place on IV infusion rate of 5
mg/hr, plus 1 mg every 10 min prn for breakthrough pain; patient who presents with pain emergency—give IV opioid
until pain level reduced by 50% to 75%, then reduce load by 2.5 times half-life to achieve maintenance level; also consider
use of high-dose dexamethasone (Decadron) and seek anesthesia and neurosurgery consultations
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Educational Objectives
| The goal of this program is to educate the listener about pain management. After hearing and assimilating this program, the
clinician will be better able to:
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| 1. Control pain in geriatric patients.
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| 2. Prescribe narcotic analgesics.
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| 3. Comprehend the limitations and potential hazards of acetaminophen and nonsteroidal inflammatory drugs (NSAIDs)
in controlling pain.
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| 4. Care for patients with cancer-related pain.
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| 5. Convert patients on immediate release opioids to long-acting and intravenous (IV) opioids.
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Discussed on This Program
Acetaminophen (N -acetyl-P -aminophenol; APAP) [Tylenol, others]
Acetaminophen with codeine (several trade names)
Celecoxib [Celebrex]
Codeine PO4
Codeine SO4 Dexamethasone [Decadron, others]
Fentanyl transdermal system [Duragesic-25, Duragesic-50, Duragesic-75, Duragesic-100, others]
Hydrocodone bitartrate (several trade names)
Hydromorphone HCl [Dilaudid, Dilaudid-5, Dilaudid-HP, Palladone]
Ibuprofen (several trade names)
Indomethacin [Indocin, Indocin SR, Indomethacin Extended-Release]
Meperidine HCl [Demerol]
Methadone HCl [Dolophine HCl, Methadone HCl Diskets, Methadone HCl Intensol, Methadose]
Misoprostol [Cytotec]
Morphine sulfate [Avinza, MS Contin, others]Naloxone HCl [Narcan]
Oxycodone and acetaminophen [Percocet, others]
Oxycodone HCl (OxyContin, others)
Propoxyphene (dextropropoxyphene) [Darvon-N, Darvon Pulvules]
Salicylic acid (several trade names)
Suggested Reading
Bloodworth D: Issues in opioid management. Am J Phys Med Rehabil 82(3 Suppl):S42, 2005; Breivik H: Opioids in
chronic non-cancer pain: indications and controversies. Eur J Pain 9:127, 2005; Brown R et al: Methadone: applied
pharmacology and use as adjunctive treatment in chronic pain. Postgrad Med J 80:654, 2004; Chelminski PR et al: A
primary care, multi-disciplinary disease management program for opioid-treated patients with chronic non-cancer pain and
a high burden of psychiatric comorbidity. BMC Health Serv Res ;13:3, 2005; Collins SD, Chessell IP: Emerging therapies
for neuropathic pain. Expert Opin Emerg Drugs 10:95, 2005; Dean M: Opioids in renal failure and dialysis patients.
J Pain Symptom Manage 28:497, 2004; Dews TE, Mekhail N: Safe use of opioids in chronic noncancer pain.
Clev Clin J Med 71:897, 2004; Gottschalk A, Smith DS: New concepts in acute pain therapy: preemptive analgesia.
Am Fam Physician 63:1979, 2001; Hanks GW, Reid C: Contribution to variability in response to opioids. Support
Care Cancer 13:145, 2005; Harden RN: Chronic neuropathic pain: mechanisms, diagnosis, and treatment. Neurologist
11:111, 2005; Jage J: Opioid tolerance and dependence—do they matter? Eur J Pain 9:157, 2005; Kalso E et al: Opioids
in chronic non-cancer pain: systemic review of efficacy and safety. Pain 112:372, 2004; Kress HG, Kraft B: Opioid
medication and driving ability. Eur J Pain 9:141, 2005; Lebovitz A: Ethics and cancer pain: why and for whom?
Pain Med 2:92, 2001; Rhiner M et al: Managing breakthrough pain: a clinical review with three case studies using oral
transmucosal fentanyl citrate. Clin J Oncol Nurs 8:407, 2004; Rubey RN: Treatment of chronic pain in persons with dementia:
an overview. Am J Alzheimer’s Dis Other Demen 20:12, 2005; Scanlon MN, Chugh U: Exploring physicians’
comfort level with opioids for chronic noncancer pain. Pain Res Manag 9:195, 2004; Stolee P et al: Instruments
for assessment of pain in older persons with cognitive impairment. J Am Geriatr Soc 53:319, 2005; Sullivan M, Ferrell
B: Ethical challenges in the management of chronic nonmalignant pain: negotiating through the cloud of doubt. J Pain 6:2,
2005; Swenson JD et al: Postoperative care of the chronic opioid-consuming patient. Anesthesiol Clin North Am
23:27, 2005; West CM et al: The PRO-SELF©: Pain Control Program—an effective approach for cancer pain management.
Oncol Nurs Forum 30:65, 2003; Wotton M: Morphine is not the only analgesic in palliative care: literature review.
J Adv Nurs 45:527, 2004.
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. For this issue, the faculty reported
nothing to disclose.
Dr. Koretz was recorded May 31, 2005, at the annual Family Practice Refresher Course, sponsored by the David Geffen
School of Medicine at the University of California, Los Angeles. Dr. Murphy spoke March 18, 2005, at the annual
Review Course for the Family Physician, sponsored by the University of Tennessee College of Medicine, Memphis.
The Audio-Digest Foundation thanks the speakers and the sponsors for making this program possible.
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