Transcript Document

We are all ignorantjust on different subjects.
- Will Rogers
7/18/2015
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Managing Chronic Pain
Hospice of St. Tammany
Palliative Care Institute of
Southeast Louisiana
Covington, LA
7/18/2015
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Introduction
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50 million people suffer from
chronic pain
Treatment with opioids is safe and
effective
New understanding of CNS
changes in chronic pain provides
rationale for treatment
Relief from suffering is our goal
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How to Manage Pain
Effectively and Efficiently
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Assessing Pain
Difference between Acute and
Chronic
Treatment of Pain
Specific Opioids
Adjuvants for Pain
Side-effects
Importance of Teamwork
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Assessing Pain
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Detailed description of pain
What makes it better or worse
Effect on emotional, social status
Do a physical assessment
Review diagnostic and lab data
Reassess often to adjust treatment
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Acute Pain
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Pathway for acute pain perception
is conventional
Duration is short
Endorphins and enkephalins are
released by CNS to block pain
perception
Opioids are effective for acute pain
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Chronic Pain
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Prolonged pain impulses cause
“burn-out” of the AMPA receptors
involved in pain transmission in the
spinal cord
Endorphins become less effective
NMDA receptors, normally
quiescient, are ACTIVATED,
causing changes in pain
transmission and behavior
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NMDA Effects in Chronic
Pain
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Windup
Neural remodeling
Activation of NK-1 receptors
Afferent becomes efferent
Neurogenic inflammation
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Treating Pain with Opioids
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Nociceptive(Somatic and Visceral) and
Neuropathic Pain
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WHO 3-step analgesic ladder
Step 1: Mild analgesics: APAP,
Propoxyphene, NSAIDS
Step 2: Moderate analgesics:
Codeine, Hydrocodone/APAP,
Oxycodone/APAP, Tramadol
Step 3: Strong Opioids
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Prescribing Opioids for
Chronic Pain- General
Principles
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Use WHO pain ladder to select analgesic
Around-the-clock, q. 3-4 hr.
Assess frequently, adjust dose
Add up total opioid taken q. 24hr.
Select long-acting opioid q. 12 hr.
Use short-acting opioid for breakthrough
pain prn.
Use one short- and one long-acting
Reassess to titrate dose
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Equianalgesic Doses if
Morphine = 10 mg p.o.
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Dilaudid(hydromorphone= 2mg
Oxycodone
= 5-10 mg
Hydrocodone =15 mg
Codeine
= 60mg
Ultram(tramadol) =50 mg
Demerol(merperidine) =50 mg
Fentanyl(duragesic)=see slide 16
Levorphanol
= 1-2 mg
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Number of Analgesic Prescriptions:
United States est. 2002 (millions)
WHO Stepladder
Total
Morphine
Fentanyl
Meperedine
Total
173.32 Hydromorphone
Propoxyphene 28.94 Methadone
Hydrocodone 91.83 All others
28.95
Total
135.30 Oxycodone
22.61
COX-2
52.94 Codeine*
Other NSAIDs 65.98 Dihydrocodeine 0.32
0.67
Tramadol
16.38 Pentazocine
*Includes Fiorinal with codeine combinations
13.03
3.67
4.35
1.78
.77
1.66
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Source:
IMS Health’s National Prescription Audit (NPA) Retail Phcy., LTC & M.O.
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Step 3 Strong Opioids
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Morphine
Oxycodone
Dilaudid (Hydromorphone)
Fentanyl
Methadone
Levorphanol
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Morphine
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Usual 1st. choice for moderate,
severe pain. Begin low, 15mg q 3-4
hr. Titrate ,reassess often.
No ceiling
Resp. depression rare in chronic
pain patients.
High doses: metabolites =
nausea,dysphoria, muscle jerks
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Dilaudidhydromorphone
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Beginning dose 2-4 mg q 3-4 hr.
Very effective, similar to MS.
Less nausea. No ceiling. Often
used orally for breakthrough pain
and i.v.
No sustained-release form.
2 mg = 10 mg MS
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Oxycodone
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Starting oral dose 5-10 mg q 3-4 hr. Very
effective
Less nausea, less troublesome
metabolites.Combined with ASA and
APAP (Percocet,etc.), limits ceiling.
Expensive sustained-release form
(Oxycontin), no ceiling. Watch for illegal
diversion. Oxycontin 10,20,40,80mg.
Liquid concentrate 20mg/ml useful
buccally in the dying, as is MS(Roxanol).
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Duragesic (Fentanyl)
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Duragesic patch: use care in
opioid- naïve patient-use 25
mcg/hr first, after pain controlled by
short-acting opioid.
To calculate dose, convert any
and all opioids to their morphineequivalent/24 hr first.
12 hr delay in onset and offset due
to skin reservoir absorption.
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Duragesic (cont’d)
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Fever increases absorption rate.
Avoid skin with scant subcut. fat.
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25mcg patch= 50 mg MS /24 hrs
50 ‘
‘ = 100 mg “
75 “
“ = 150 mg “
100 “
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(approx.)
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Methadone and
Levorphanol
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Under-used, not marketed
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NMDA receptor-blocking activity
makes these, especially
methadone, the best choice for
neuropathic and complex chronic
pain
Levorphanol is 4-8x stronger than
MS: longer ½ life (q 6 hrs)
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Advantages of
Methadone
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Long duration of action
Short initial distribution half-life
No active metabolites
No ceiling dose
NMDA receptor-blocker action in spinal
cord (important in neuropathic and
chronic pain)
Cost: approx. $20-25/month( vs. $200500/mo. for hydromorphone,sust.act.
morphine,oxycodone,fentanyl patch.
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Advantages (cont’d)
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Potency at least equal to morphine
Oral, rectal absorption excellent
Low incidence of side-effects
Less constipating
Lower incidence of tolerance
Available for iv infusion use
Most important,methadone is both a mu
opioid agonist and an NMDA receptor
antagonist as it relates to pain relief
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Disadvantages
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Stigma and association with
substance-abuse
Accumulation due to long and
variable elimination half-life in
some persons
Said to be hard to convert to and
from other opioids
Fear of regulators
Lack of education and experience
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Cost Comparison of
Opioids ( 30 day supply)
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Duragesic Patch 25mcg/hr $ 140
Duragesic Patch 100 mcg/hr $ 430
Oxycontin 40 mg q 12 hr
$ 250
MS contin 60 mg q 12 hr
$ 210
Dilaudid 4 mg q 4 hr ATC
$ 118
Percocet 5 mg q 4 hr ATC $ 210
Levorphanol 2 mg q 6 hr
$ 120
Methadone 10 mg q 8 hr
$ 20
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108 outpatients with cancer
pain on opioids 103
successfully switched to
methadone – oral q 8 hrs
with significant reduction of
pain
• Bruera E et al, Proceeding of the 9th
World Congress on Pain, 2000,
p. 957
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52 prospective, consecutive
patients with either
uncontrolled cancer pain on
opioids or intolerable side
effects switched to
methadone. All had
significant reduction of pain
and significantly less
nausea, vomiting,
constipation and
drowsiness.
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• Mercandante S et al, Journal of
Clinical Oncology. 2001; 19:2898290425
Personal experience:
Prescribing Methadone
2001-2003
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Palliative Care Consults(total) 140:
Methadone for Chronic pain: 88
Excellent relief( pain reduced
from 7-10 to 0-3) : 50
Fair relief (pain reduced to 46):
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No benefit or side-effects: 20
( Nausea 6, Sedation 12, Depression 2)
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Adjuvants for Pain
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For Neuropathic pain:
Tricyclic antidepressants
Anticonvulsants
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For bone and soft-tissue pain:
NSAIDs,corticosteroids,palliative
radiation,biphosphonates, tricyclics
For visceral pain: corticosteroids,H-2
blockers,metoclopropamide
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The doctor is
the
most powerful
adjuvant.
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DOCTOR AND
PATIENT WORK
TOGETHER TO
ACHIEVE
INCREMENTAL
IMPROVEMENT
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Good sleep
Pain free at rest
Pain free during activities
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Nociceptive pain
 Tissue
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Neuropathic pain
 Nerve
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damage
damage
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CANCER
PATIENTS
65% nociceptive
 5% neuropathic
 30% mixed
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TCA
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Tertiary amine
Amytriptaline (Elavil)
 Impramine (Tofranil)
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Secondary amine
Nortriptyline (Pamelor)
 Desipramine (Norprimine)
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Secondary
amines have equal 5HT,
NE potency
Secondary amines have half the
side effects
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ADJUVANTS
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One adjuvant at a time, targeted to the
specific symptom
Tricyclic antidepressants (amitriptyline,
nortriptyline, desipramine, venlafaxine) for
pain described as “constant burning pain”
Anticonvulsants (Gabapentin, valproate,
carbamazepine, clonazepam) for pain
described as “shooting, stabbing, electric
shock pain”
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WHY AED?
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Inhibit excessive neuronal activity
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Inhibit excitatory systen
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glutamate
Activate inhibitory
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Na channel blockade
GABA
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GABAPENTIN:
CANCER PAIN
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N = 22 cancer patients with refractory pain
Gabapentin was added to opioid treatment
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800 mg to 1800 mg/day
Results
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Pain decreased from 6.4 to 2.1 (0 - 10
scale)
Burning pain decreased from 5.1 to 2.0
Shooting pain decreased from 7.2 to 2.2
Allodynia disappeared in 7 0f 9
 Caraceni
et al j Pain Sympt Manag
1999; 17:441-445
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DIABETIC PERIPHERAL
NEUROPATHY PAIN
GABAPENTIN VS.
AMITRIPTYLINE
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N = 28, double-blind, cross-over
Gabapentin 900-1800 mg/day
Amitriptyline 25-75 mg/day
Results: No difference in pain relief or
global pain score data
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Moderate or greater pain relief in 52% of
GBP vs. 67% (AMT)
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Arch Intern Med 1999;159:1931-1937
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TCA – 10 - 100 mg
AED – full dose, except
Valproic acid(usually
250 mg once daily
hs.)
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Side-effects of Treatment
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Opioid adverse effects:
nausea,constipation,somnolence,
dysphoria, muscle jerks, itching,
respiratory depression
Neuropathic adjuvant side-effects:
dizziness ,sleepiness, low BP, liver
toxicity(uncommon)
NSAID side-effects: nausea, GI
ulcer or bleeding,
edema,decreased renal function
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Importance of Teamwork
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Complex chronic pain, especially if
caused by life-threatening disease,
is best treated by a team.
The diverse talents of physician,
nurse, social worker, chaplain,
working together offers
comprehensive control of physical,
emotional, and spiritual pain.
Palliative care is for ALL patients
who are suffering.
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