PAIN MANAGEMENT
From Family Medicine: Pearls, Perils, and Practice Guidelines, sponsored by the Loma Linda University School of
Medicine
Gina Mohr, MD, Assistant Professor of Family Medicine and Director of Palliative Medicine, Loma Linda
University School of Medicine, Loma Linda, CA
Goals and Objectives of Palliative Care
| Goals: relieve suffering; improve quality of life (QOL) in patients with severe complex life-limiting illnesses;
achieve best QOL for patients and family members; defined by World Health Organization as active total care of
patients whose disease not responsive to curative treatment; control pain and other symptoms; implementing—can
be applied early in disease; never tell patient, “I’m sorry, there is nothing more I can do for you”; begin palliative
care at presentation of illness (how patients given diagnosis can affect how illness proceeds); increase amount of
palliative care as curative treatment becomes less effective
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Barriers to Pain Management
| Physician barriers: failure to ask about pain; incomplete assessment; lack of knowledge about opioid use; lack of
time; fear of addiction and regulatory oversight; in California, 12 hr of continuing medical education about pain
management and end-of-life care required (physicians can be sued for over- and underprescribing [as in, eg, cases
of elder abuse]); medical boards rarely investigate physicians without proper cause; cases in media usually involve
gross mishandling by physicians
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| Patient barriers: unwillingness to complain about pain; fear physicians may not treat pain or may lower doses of
chemotherapy or radiation; not wanting to bother physician; not expecting relief from pain; fear of opioids, addiction,
and side effects; inability to afford costs; cultural views; family members (can present barriers)
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| Institutional or regulatory barriers: low priority for pain in medicine; lack of emphasis on symptom management
in medical education; state requirements for prescribing with triplicates (no longer required in California; security-prescription
forms used instead of triplicates for better access to pain management); abuse of prescription
medication; lack of cause and effect between prescribing medications for appropriate use and diversion; possibility
of addiction (may be overemphasized)
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Physical Dependence vs Addiction
| Physical dependence: process of neuroadaptation; occurs with long-term opioid use; abrupt withdrawal (does not
indicate addiction); tolerance—over time, effectiveness of dose decreases and may need to be increased (common
in long-term dosing); with, eg, cancer patients, often indicates progression of disease; in patients with chronic pain,
dose may keep patients comfortable for years
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| Addiction: psychologic dependence; compulsive use; patients no longer in control of use of medication; loss of interest
in pleasurable activities; continued use despite harm (eg, losing job); rare outcome of pain management, particularly
in patients with no history of substance abuse; ≈10% of patients treated for chronic pain may become
addicted; addiction lessens QOL; pseudoaddiction—first seen in patients with sickle cell disease; drug-seeking behavior
(eg, patients complain of pain although they appear comfortable) for psychologic use; many patients may be
undertreated (respond well to appropriate titration); addiction directly converse to goal of pain management; appropriately
treat addiction
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| Personal nature of pain: explore previous treatment experiences; meaning or impact of pain on physical, social,
emotional, and spiritual life; expectations for relief
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| Pathophysiology of pain: acute—relatively easy to treat; caused by injuries that can be seen (eg, fractured leg
from skiing); treat appropriately; chronic—difficult to see underlying cause; failure to treat acute pain aggressively
may result in chronic pain; different patients deal with pain in different ways
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Evaluation of Analgesic Medications
| Over-the-counter medications: eg, acetaminophen (eg, Tylenol), ibuprofen; readily available; side effects—
liver damage with >4 g daily of acetaminophen; anti-inflammatory agents have ceiling effects (ie, using more than
recommended dosage does not increase analgesic effect, but increases side effects, particularly gastrointestinal, renal,
and bleeding problems); more people annually present to emergency department for perforated gastric ulcers
from nonsteroidal anti-inflammatory drugs (NSAIDs) than for overdose of opioids
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| Not recommended: meperidine (Demerol)—highly abused; causes most euphoria; poorly absorbed orally; breaks
down into metabolite (normeperidine; has no analgesic effect and longer half-life; can cross blood-brain barrier and
cause myoclonus, seizure, or death); single dose may be appropriate for patients undergoing procedure (eg, esophagogastroduodenoscopy
[EGD], colonoscopy); frequent dosing (eg, q3-4h) for pain can be harmful, particularly in
patients with renal failure; propoxyphene plus acetaminophen (Darvocet)—shown no better than placebo; can
cause some euphoria; breaks down into toxic metabolite at high doses; mixed agonist-antagonists—pentazocine
(Talwin); alternating with morphine partially reverses effects of morphine
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Opioid Pharmacology
| Available opioids: hydrocodone—eg, hydrocodone and acetaminophen (Vicodin; Norco; Lorcet); short-acting
oral medications; widely abused in California; morphine (MS Contin)—gold standard; oral or intravenous (IV);
short- or long-acting; oxycodone (OxyContin)—oral; long-acting; OxyContin is oxycodone in slow-release tablet;
addicts crush capsule for euphoric effect (may lead to overdose and respiratory depression); oxycodone and acetaminophen
(Percocet) short-acting; hydromorphone (Dilaudid)—oral or IV; short- or long-acting; Palladone
(long-acting) removed from market
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| Pharmacology: excreted in kidneys; conjugated in liver; undergo first-order kinetics; oral medications—onset
within 30 min; peak at ≈1 hr; half-life ≈3.5 hr; effect of bolus dosing (patients begin to feel pain after 3.5 hr, but
cannot take next dose until 4 hr [results in peaks and troughs of pain relief followed by pain]); IV medications—
peak higher and sooner (10-15 min) and wear off more quickly (1-2 hr); steady state of medications—oral medications
usually dosed every 4 hr; steady state reached in ≈24 hr; steady state reached in 2 to 3 days with long-acting
medications (eg, morphine or oxycodone)
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| Equianalgesic doses: oxycodone, hydrocodone, and morphine have roughly 1:1:1 conversion ratio (hydrocodone
probably slightly less potent than morphine; morphine slightly less potent than oxycodone); IV morphine 3 times
as potent as oral morphine (when converting from IV to oral morphine, multiply by 3 for same amount)
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| Routine oral dosing: immediate-release preparations—usually dosed every 4 hr; if patient has mild to moderate
pain, increase 24-hr dose by 25% to 50%; if patient has severe or uncontrolled pain, increase 24-hr dose by 50% to
100%; extended-release preparations—typically dosed every 12 hr; in some cases of high doses, interval can be
decreased to every 8 hr; tell patients crushing or chewing medications negates long-acting properties and can lead
to overdose; adjust dosing after 2 to 4 days (ie, wait for steady state before increasing)
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Case Studies
| Case 1: woman 45 yr of age with breast cancer and metastasis to bone; taking Vicodin (5 mg hydrocodone/500 mg
acetaminophen; 12 tablets daily); pain rating 8 to 9 on 10-point scale; management—because short-acting medications
dosed every 4 hr and have bolus effect, switch to long-acting agent; calculate current amount of hydrocodone
(5 mg x 12 = 60 mg daily) and acetaminophen (500 mg x 12 = 6000 mg daily; patient at risk for acetaminophen
toxicity and liver problems); acetaminophen content limits use of Vicodin, Norco, Lorcet, and Percocet; available
long-acting oral medications include morphine or oxycodone; since patient’s pain severe (pain rating >7), increase
24-hr dose by 50% to 100%; patient should receive equivalent of 120 mg hydrocodone daily (ie, MS Contin 60 mg
po q12h); breakthrough dosing—use immediate-release opioids; patients should get 10% of 24-hr dose, dosed every
1 to 2 hr (because short-acting opioids peak at ≈1 hr); goal to avoid using >3 doses of breakthrough medication
in one day; in this case, patient should use 10 mg of immediate-release morphine (10% of 24-hr dose = 12 mg
[rounded to 10 mg]) q1-2h for breakthrough pain; if patient requires >3 doses for breakthrough pain in one day, increase
dose of long-acting medication
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| Case 2: woman with metastatic cancer (primary cancer unknown); patient stable on MS Contin 300 mg q8h for 6 to
8 wk, then developed severe acute back pain; management—switch from oral morphine to IV morphine to treat
acute pain (ratio 1:3; 900 mg oral morphine daily divided by 3 = 300 mg IV morphine daily); since pain severe, increase
dose by 100% (patient needs 600 mg IV morphine daily); IV medications given hourly (for this patient, 25
mg/hr); opioid-dependent patients require more than opioid-naive patients; subcutaneous (SQ) line—patient lost
IV access and could no longer swallow; disease progressed; goal included being home with family; SQ line started;
IV to SQ conversion ratio 1:1; limited by volume (higher concentration required); patient switched to Dilaudid (≈4
times as potent as IV morphine); 24 mg/hr IV morphine divided by 4 = 6 mg/hr of Dilaudid; patient lived comfortably
for another 3 wk at home (with hospice care) before dying
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| Ongoing assessment: continue assessment; increase analgesics until pain relieved; when side effects unacceptable
(eg, myoclonus, hallucinations), convert to another opioid; be prepared for sudden changes in pain; driving—safe
if patient on stable dose of opioid, without sedation; unsafe if dose being titrated; clearance concerns—in patients
with dehydration, renal failure, or liver failure, increase dosing interval or decrease dose size; if patient anuric, stop
routine dosing and give prn dose only
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| Case 3: woman with gastric cancer unable to swallow due to obstruction in stomach; comfortable on morphine drip
of 5 mg/hr; patient’s goal to return home without IV line; intramuscular dosing painful and not recommended; SQ
or transdermal medication helpful; transdermal fentanyl—expensive (use appropriately); onset 12 hr, peaks at 24
hr, and lasts 48 to 72 hr; ensure patch adheres to skin and patient has enough SQ fat to absorb drug; 25-µg patch =
≈50 mg oral morphine; management—patient on 120 mg IV morphine daily, or 360 mg (round to 400 mg) oral
morphine daily; patient needs 200 µg of transdermal fentanyl (two 100-µg patches q72h); start patch 1 to 2 days before
discharge
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Opioid Side Effects
| Common side effects: dry mouth; constipation—common to all opioids; effects on central nervous system (CNS;
spinal cord) and myenteric plexus; easier to prevent than to treat; dietary approach usually not sufficient, particularly
in inactive palliative care patients; bulk-forming agents (eg, psyllium [eg, Metamucil]) require greater water
intake and not recommended; stimulant laxatives (eg, sennosides [eg, Senna-Gen; Senokot]) combined with stool
softener (eg, docusate [eg, Colace]) recommended (1 tablet bid may not be enough; highest dosage of Senokot 4
tablets bid); another agent may be needed; aim for regular soft comfortable bowel movements; nausea and
vomiting—particularly common when initiating opioids; tolerance develops within few days; patients who continue
to have nausea may need premedication with metoclopramide (eg, Reglan; 10 mg, 20-30 min before taking
opioid); haloperidol (Haldol) powerful antiemetic and helpful in patients who do not respond to Reglan, prochlorperazine
(eg, Compazine), or promethazine (eg, Phenergan); sedation—usually occurs during initiation of opioids;
must be distinguished from exhaustion due to pain; tolerance occurs within few days; if fatigue continues, low
doses of psychostimulants (eg, 5-10 mg of methylphenidate [eg, Ritalin]) in morning can boost energy, elevate
mood, and maintain pain control
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| Uncommon adverse effects: delirium; hallucinations; myoclonus (usually with higher doses); respiratory
depression—consider goals (eg, keeping patients comfortable as they die); pain potent stimulus to breathe; when
patients become sleepy from opioids, giving naloxone (Narcan) can catapult them into wakefulness (but also pain);
sedation occurs well before respiratory depression; Narcan may be needed in cases of error (eg, nurse reads 5 mg
morphine as 50 mg and gives large bolus); when opioids appropriately titrated, respiratory depression rare; if patient
appears sedated, decrease opioid or increase interval and monitor; small doses of opioids may help relax
patients who have respiratory distress due to pneumonia, exacerbation of congestive heart failure, or chronic obstructive
pulmonary disease
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| Institutional promises to patients: often from marketing efforts (eg, slogan “where miracles happen every
day”); patients may become disappointed; goals—manage pain; keep patient comfortable in private room so family
can be there; provide spiritual care; pet therapy
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Questions and Answers
| How to handle dry mouth? use scopolamine to dry secretions and to reduce gurgling; patients often have cracked
lips; aggressive oral care; IV fluids not necessarily helpful; fluids may produce more discomfort and harm by causing
pulmonary or peripheral edema or ascites; stop fluids and perform good oral care (eg, swabbing with ice water;
white petrolatum [Vaseline] on lips); few sips of cold water or ice chips
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| When to involve palliative care? from beginning of serious illness; important to establish relationship with patients
as they undergo curative treatment; as curative treatment becomes less effective, palliative care may become
primary service; integrate when managing patients with severe and potentially life-limiting illnesses; focus on goal
planning to keep patients comfortable; discuss advanced directives; “earlier the better”
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Suggested Reading
Auret K et al: Underutilisation of opioids in elderly patient with chronic pain: approaches to correcting the problem.
Drugs Aging 22:641, 2005; Blake S et al: Experiences of patients requiring strong opioid drugs for chronic non-cancer
pain: a patient-initiated study. Br J Gen Pract 57:101, 2007; Clemens KE et al: Symptomatic therapy of dyspnea
with strong opioids and its effect on ventilation in palliative care patients. J Pain Symptom Manage 33:473, 2007;
Estfan B et al: Respiratory function during parenteral opioid titration for cancer pain. Palliat Med 21:81, 2007; Fine
RL: Ethical and practical issues with opioids in life-limiting illness. Proc (Bayl Univ Med Cent) 20:5, 2007; Glare P
et al: The adverse effects of morphine: a prospective survey of common symptoms during repeated dosing for chronic
cancer pain. Am J Hosp Palliat Care 23:229, 2006; Kyle G: Constipation and palliative care - where are we now? Int
J Palliat Nurs 13:6, 2007; Litkowski LJ et al: Analgesic efficacy and tolerability of oxycodone 5 mg/ibuprofen 400
mg compared with those of oxycodone 5 mg/acetaminophen 325 mg and hydrocodone 7.5 mg/acetaminophen 500 mg
in patients with moderate to severe postoperative pain: a randomized, double-blind, placebo-controlled, single-dose,
parallel-group study in a dental pain model. Clin Ther 27:418, 2005; Miller NS et al: Patient characteristics and risks
factors for development of dependence on hydrocodone and oxycodone. Am J Ther 11:26, 2004; Rodriguez RF et
al: Incidence of weak opioids adverse events in the management of cancer pain: a double-blind comparative trial. J
Palliat Med 10:56, 2007; Swegle JM et al: Management of common opioid-induced adverse effects. Am Fam Physician
74:1347, 2006; Ziegler PP: Addiction and the treatment of pain. Subst Use Misuse 40:1945, 2005.
Educational Objectives
| The goal of this program is to improve quality of life in patients with severe life-limiting illnesses through optimal
pain management and palliative care. After hearing and assimilating this program, the participant will be better able
to:
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 | 1. Recognize barriers to pain management.
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| 2. Discuss over-the-counter medications and their side effects.
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| 3. Evaluate properties of opioids to prescribe the best treatment.
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| 4. Use the equianalgesic table to calculate opioid conversions.
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| 5. Prevent and treat side effects of opioids.
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Faculty Disclosure
In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty members to disclose
relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any
identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary
business or commercial interest. For this program, the faculty reported nothing to disclose.
Acknowledgements
Dr. Mohr spoke on June 25, 2006, in Loma Linda, CA, at Family Medicine: Pearls, Perils and Practice Guidelines,
presented by the Loma Linda University School of Medicine. The Audio-Digest Foundation thanks Dr. Mohr and the
Loma Linda University School of Medicine for their cooperation in the production of this program.
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