Principles and Practice of Intraspinal Drug Infusion for Chronic Pain

1
Principles and Practice of Intraspinal Drug
Infusion for Chronic Pain

• Richard K. Osenbach, M.D.
• Director of Neurosciences and Neurosurgery
• Cape Fear Valley Health System
• Fayetteville, NC

2
History of Opiate Analgesia

• 1901 - intrathecal injection of morphine
• 1915 - antagonist of morphine discovered
• 1951 - 1st human use of morphine antagonists
• 1976 - 1st use of IT morphine in animals
• 1980 - spinal morphine used for cancer pain

3
Spinal Opiate Analgesia

• Discovery of CNS opiate receptors
• Identification of endogenous opiate peptides
• Isolation of receptors

4
Endogenous Opioid Peptides

• Proopiomelanocortin (POMC)
• Endorphins
• Beta-lipotropin
• Proenkephalin A
• Met-enkephalin, leu-enkephalin
• Other enkephalins, peptide E
• Prodynorphin
• dynorphin A B
• neoendorphins (? and ?)

5
Opioid Receptors and Ligands
Opioid Receptor Endogenous Agonist Synthetic Agonists Antagonists
Mu (70) ß-Endorphin Endomorphins Morphine DAMGO Naloxone ß-FNA
Delta (20-30) Met-Enkephalin Leu-Enkephalin DPDPE SNC-80 DSTBULET Naltrindole Naloxone
Kappa (5-10) Dynorphine A Dynorphine B
hORL1 Nociceptin/OFQ None
6
Mu Receptor

• Defined by affinity for morphine
• Less affinity for other receptor subtypes
• Most clinically important opioids selective for
  Mu receptor
• Cross react at higher doses
• ?1 - supraspinal ?2 spinal
• Most analgesic effects of systemic morphine
  mediated through ?1 effects
• 70 located pre-synaptically

7
Morphine

• High affinity for the Mu receptor
• 50x less affinity for delta receptor
• Minimal affinity for kappa, hORL1 receptor
• Most physiological effects through action at Mu
  receptor
• Non-Mu effects with very high doses
• No evidence fo Mu-Delta cross tolerance

8
Opioid Recptor Physiology

• G-protein-coupled receptor family
• Synthesized in DRG
• Second messenger using camp
• Negative coupling
• Inhibit camp via Gi-protein
• ? And ? - opening of K channels
• ? - Closing of ca2

9
Opioid Receptor Physiology

• ? And ? - opening of K channels
• ? - Closing of ca2

10
Opiate Receptors

• Distributed pre- and post-synaptically
• High affinity binding
• Binding stereospecific
• Optimal binding in ph range 7-8

11
Opioid RecetorsAnalgesia

• Dorsal horn
• Lamina I
• Substantia gelatinosa
• Brainstem
• Nucleus caudalis
• Supraspinal
• PAG
• Medial and intralaminar thalamic nuclei
• Striatum

12
Opioid RecptorsAutonomic Effects

• Cough suppression, orthostatic hypotension
• Nucleus tractus solitarius and ambiguous, locus
  ceruleus
• Respiratory depression
• Nucleus tractus solitarius, parabrachial nucleus
• Nausea/vomiting
• Area postrema
• Meiosis
• Superior colliculus, pretectal nuclei

13
Opioid ReceptorsMiscellaneous Effects

• Endocrine effects
• Posterior pituitary inhibition of vasopressin
• Hormonal effects hypothalamic infundibulum
• Behavioral effects
• Amygdala, hippocampus, nucleus accumbuns, basal
  ganglia
• Motor rigidity
• Striatum

14
Actions of Spinal Opiates

• Application to spinal cord produces rapid and
  potent analgesia
• Reduction in activity in spinal projection
  neurons in lamina V
• Increases latency of pain behavior responses in
  animals
• Effects reversed with naloxone

15
Spinal Opiate AnalgesiaPre-synaptic Actions

• Presynaptic action at neuron terminals
• C-fiber terminal zones in lamina I II
• Receptors synthesized in DRG
• rhizotomy - 70 reduction
• Activation - inhibition of nerve terminal
• Reduction in transmitter release
• tachykinins, excitatory AA, SP
• Opening of K channels
• Closing of ca2 channels

16
Spinal Opiate AnalgesiaPost-synaptic Actions

• Receptors on neuronal cell body or dendritic
  projections
• Post-synaptic hyperpolarization
• identical ionic mechanisms
• Reduction in evoked electrical activity
• 25 Mu and Delta receptors located on neurons
• Requires higher doses of systemic morphine
• eg. A-fiber mediated allodynia

17
Spinal Opiate AnalgesiaDisinhibitory Effect

• Indirect post-synaptic action involving 3 neuron
  circuit
• Enkephalin neurons in SG
• GABA effect
• Inhibition of inhibitory interneuron
• Increased activity of second inhibitory
  interneuron (release from inhibition)
• Depression of activity in output neurons

18
Supraspinal Descending Modulation

• 1) wall transection of spinal cord results in
  increased activity of lamina V neurons to noxious
  input ? Bulbospinal pathway exerts tonic
  inhibitory control on nociceptive neurons
• 2) stimulation of specific brainstem sites
  produces a highly specific suppression of the
  responses to noxious stimuli that is reversed by
  monoamine receptor antagonists
• 3) discreet lesions of the DLF block the
  inhibitory effects of stimulation-produced
  analgesia
• 4) microinjection of local anesthetics into the
  NRM blocks stimulation-produced analgesia from
  PAG stimulation

19
Descending Modulation
20
Rationale for IT Drug Delivery

• Provide high concentration of drug at the site of
  interaction with spinal receptors and minimize
  spread to other regions in the brain

21
Factors Affecting Drug Distribution

• Patient characteristics
• CSF properties
• Drug properties
• Injection technique

22
Injection Factors

• Site of injection
• Subarachnoid vs. Epidural
• Velocity of injection
• Turbulence (barbotage)
• Bolus vs. continuous infusion

23
Drug Properties

• Lipid solubility
• Dose and volume
• Baricity
• Vasoconstrictors

24
Pharmacokinetics of IT Opioids

• Uptake by spinal cord
• Depends lipid solubility of drug
• Rostral - caudal distribution by bulk flow
• Transdural absorption - systemic uptake

25
Continuous IT Drug InfusionHydrophilic Drugs

• Concentration gradually increases and
  concentration gradient develops
• 5 -7 half-lives to reach steady state
• Distribution ratio constant regardless of drug
  concentration
• Final steady state concentration proportional to
  dose infused

26
Continuous IT Drug InfusionLipophilic Drugs

• Rapidly absorbed after contacting cell membranes,
  blood vessels, BBB
• Rapidly lost from CSF and systemically
  redestributed
• Localized distribution
• catheter tip must be close to intended site of
  action or high infusion dates must be used

27
Epidural Infusion

• Epidural space acts as a reservoir for slow
  release of drug
• Release variable
• Timing of drug effects more unpredictable
• 2 - 3 epidural morphine crosses dura into CSF
• Equi-analgesic effect requires 10x the amount of
  drug given epidurally

28
Intraspinal MorphineConversion Ratios

• 300 mg oral morphine
• 100 mg parenteral morphine
• 10 mg epidural morphine
• 1 mg intrathecal morphine
• May not be accurate at high doses

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Alternative Agents

• Alpha-2 agonists
• clonidine, tizanidine, dexmedotomidine
• Local anesthetics
• Bupivicaine, ropivicaine
• Somatostatin analogs
• octreotide
• Calcium channel blockers
• SNX-111 (zicontide)
• NMDA Antagonists
• ketamine, dextrmethorphan, methadone
• Miscellaneous agents
• Adenosine, midazolam, gabapentin, aspirin

31
? - 2 Adrenergic Agonists

• Inhibition of SP release
• Inhibition of nociceptive neurons
• Site of action separate from opiates and local
  anesthetics
• Synergistic with opiates
• Approved for medium-term epidural infusion for
  cancer pain
• Daily dose 50 - 900 ?g
• Side effects hypotension

32
Calcium Channel Blockers SNX-111

• Antagonists of N-type Ca2 channels
  anti-nociceptive in animals models of acute,
  chronic, neuropathic pain
• synthetic form of ?-conopeptide MVIIA
• Inhibits evoked nociceptive behavior in rats when
  given IT

33
Staats Et Al, 1998Chronic,intractable
neuropathic Pain Marked Analgesic Efficacy of
ziconotide

• Randomized, prospective, double-blind,
  placebo-controlled trial
• N102, VASPI score ? 50
• Response ? 30 reduction in VASPI from baseline
  without an inc. in opiate requirements

34
Penn et al, 1992Octreotide for Cancer Pain
35
Drug Selection
36
Patient Selection

• Observable concordant pathology
• Opioid-responsive pain
• Failure of less invasive, complex therapy
• Failure of long-acting oral opioids
• Surgically-correctable pathology excluded
• Psychological clearance
• Successful screening trial
• Life expectancy gt 3 months (cancer pain)

37
Exclusion Criteria

• Major psychological issues
• Substance abuse history
• Unresolved secondary gain issues
• Medical contraindication for surgery
• Spinal pathology precluding catheter placement
• Allergy to opiates

38
Principles of Screening

• Accurately select candidates for long-term IT
  drug delivery
• Physician and patient should define goals for IT
  drug delivery BEFORE proceeding with a trial
• Goals defined on a case-by-case basis
• Theoretically, the trial should approximate as
  closely as possible the conditions of long-term
  therapy
• IT drug delivery is represents only a SINGLE
  element in overall long-term pain management for
  a given patient

39

• A SUCCESSFUL TRIAL DOES NOT GUARANTEE LONG-TERM
  SUCCESS OF IT INFUSION

40
Trial AssessmentGoals of Screening

• Success of an IT drug trial must be defined in
  the context of the goals that are set
• Analgesic response
• What is significant?
• One mans junk is
• another mans treasure
• Drug-related side effects
• Mood
• Functional improvement

41
Trialing for IT Therapy
What do we know about screening?

• Multiple accepted methods
• No consensus as to the single best method

42
Screening Methods

• Single bolus
• Multiple boluses
• Continuous infusion, functional trial

Intrathecal or epidural
43
Survey of Trialing Methods

• Continous epidural infusion 35.3
• Bolus IT injection 33.7
• Bolus epidural injection 24.5
• Continuous IT infusion 6.4

1999 Survey of Academic Teaching Programs 52
using continuous infusion 59 using IT route 17
using epidural route only 22 using both routes
44
Single IT Bolus Trial

• ADVANTAGES
• Procedurally simple
• Low cost
• Low risk and morbidity
• DISADVANTAGES
• Sub-analgesic drug levels false negative trial
• Side effects may obscure analgesic response
• Higher likelihood of placebo response
• Inability to determine accurate starting dose
• Inability to evaluate ADL

45
Multiple Bolus Injections

• ADVANTAGES
• Ability to titrate dose
• Establish dose-response curve
• Placebo injections for comparison with active
  drug administration
• DISADVANTGES
• Increased incidence of side effects
• Transient vs. sustained
• Lack of correlation with continuous infusion
• Multiple dural punctures required for IT delivery
  unless temporary catheter used
• More costly and time-consuming

46
Functional (Continuous) Trial

• ADVANTAGES
• Controlled dose titration
• Assess starting dose for IT therapy
• Reduce risk of drug-related side effects
• Dissipates placebo effect over time
• Assessment of functional outcome
• DISADVANTGES
• Procedurally more complicated
• Requires greater expertise
• Higher morbidity
• More costly

47
Epidural vs. Intrathecal
CRITERIA EPIDURAL INTRATHECAL
Onset of Action Slower onset of analgesia Faster onset of analgesia
Systemic Effects Greater systemic effects Minimal systemic effects
Duration of Effect Shorter-lasting Longer-lasting
Dose Higher dose to achieve effect Lower dose required (1/10 epidural dose)
Adverse Effects/Risks Higher incidence of systemic side effects Risk of epidural abscess Post-LP headache Respiratory depression Meningitis
48
Placebo Administration

• Rationale reduce the likelihood of a false
  positive trial
• Normal individuals may exhibit a placebo response
• Difficulty interpreting placebo response
• A positive placebo response should not
  necessarily mean no pump
• Functional trialing with dose titration
  dissipates the placebo response over time

49
Dosing

• Primary determinants
• Route of administration
• Current dose of systemic opioids
• Large doses of systemic opioids will confer some
  degree of tolerance
• Higher IT dose tolerated (required)
• Convert total daily dose of opioid to intraspinal
  morphine equivalent
• Epidural 10 systemic dose
• Intrathecal 0.5-1 systemic dose

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Oral Opioids During Trial

• No consensus on alteration of systemic opioids
  during the trial
• Maintaining the patient on a portion of their
  daily dose will lessen the likelihood of
  withdrawal
• Withdrawal from systemic opioids may result in
  reduction in opioid-induced hyperalgesia
• May produce a false positive result
• 50-75 reduction in systemic dose
• Liberal use of breakthrough medication
• Minimal use of breakthough medication can be
  taken as one objective measure of pain relief

51
Monitoring During Trial

• Vital signs, pulse oximetry, apnea monitor
• Pain reduction
• VAS
• Percent pain relief
• Assessment of mood
• Functional assessments
• SF-36
• MPQ
• Oswestry disability index
• Drug-related side effects
• Supplemental opioid use

52
Side Effects of Spinal Opioids

• Pruritis
• Urinary retention
• Nause/vomiting
• Sedation
• Respiratory depression

53
Continuous Epidural Infusion Trial

• Tunneled epidural catheter
• Morphine infusion, 0.2mg/cc
• Starting dose, 0.2mg/hr (1cc/hr)
• Dose titration for 36-48 hours
• Final dose 4.8-48mg/day
• IT dose 0.48 4.8mg MS/day

54
Continuous IT Trial

• Tunneled IT catheter
• Algoline catheter, 33.5 inches
• .0156 m./in 0.5226 ml catheter volume
• Calculate IT equi-analgesic dose
• Morphine used as 1st line agent
• Reduce systemic opioids by 50
• Assess VAS scores every 2 hours
• Monitor development of side effects
• Titrate infusion to analgesic effect

55
Quantitative Crossover Double-blind IT Trial
Phase I Dose Escalation Trial

• Baseline VAS score
• Bolus injections of IT morphine separated by 30
  minute
• Drop in VAS lt 3, repeat IT morphine
• Drop in VAS gt 3, proceed to Phase II

Levy R, M.D, Ph.D.
56
Quantitative Crossover Double-blind IT Trial
Phase II Double-Blind Crossover Trial IT
Morphine vs. Saline

• Day 1
• Drug A VAS scores for 6 hours
• VAS scores within 1 point of baseline
• Drug B
• Day 2
• Drug A VAS scores for 6 hours
• VAS scores within 1 point of baseline
• Drug B

Levy R, M.D, Ph.D.
57
IT Bolus (ITB) vs. Continuous Epidural Infusion
(CEI)

• 86 patient screened for inclusion
• 28 excluded from inclusion
• 58 patients approached
• 18 declined inclusion
• 40 patients randomized
• ITB (n18) or CEI (n19)
• 27 successful trial - pump implantation
• ITB, 67 (12/18) CEI, 79 (15/19)
• 3 patients lost to follow-up
• ITB (n10), CEI (n14

Anderson V, Burchiel K, Cooke B A Prospective
Randomized Trial of Intrathecal Injection vs.
Epidural Infusion in the Selection of Patients
for Continuous Intrathecal Opioid Therapy.
Neuromodulation, 2003
58
IT Bolus vs. CEI

• No significant difference in 6 month outcomes
  between ITB and CEI
• ITB 60 successful response
• CEI 64 successful response
• Drug-related complications more common in ITB
  group (88) vs. CEI group (70)
• CEI 2.5 times more costly (4,762 vs. 1,862)

CONCLUSION Differences in pain and functional
response to long-term IT opioids among patients
selected by either trial method are not large
59
IT Bolus vs. CEI
Anderson V, Burchiel K, Cooke B A Prospective
Randomized Trial of Intrathecal Injection vs.
Epidural Infusion in the Selection of Patients
for Continuous Intrathecal Opioid Therapy.
Neuromodulation, 2003
60
Questions Regarding Trialing

• Screening method
• Duration of trial
• Drug and dose
• Use of placebo
• Systemic opioids
• Criteria for success

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Pump Implantation

• Catheter insertion
• Tunneling and anchoring of catheter
• Pump pocket preparation
• Preparation and filling of pump
• Connection of catheter to pump
• Anchoring of pump

62
Catheter Complications

• Fractures
• Occur around spinous processes with midline
  catheter placement
• Withdrawal of catheter through needle
• Kinks
• Occur at connections and anchors from lack of
  slack and/or not using a strain relief sleeve
• Holes
• Missing or failed strain relief sleeve at pump
  connector on one-piece catheter
• Several reports of small holes in one-piece
  catheter under pump. No reports of holes under
  the pump with the two-piece catheter
• Dislodgements
• Occur from pump movement and lack of slack at
  pump and catheter causing the catheter to slip
  through anchor
• Occur from ligament motion or CSF pressure and no
  anchor or purse string suture at fascial entry
  point

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Catheter ComplicationsMedtronic Clinical Study
64
Catheter Complications
Proper catheter placement is probably the single
most important aspect of pump implantation for
avoiding device-related complications

• 20-25 incidence
• 20,000 implants annually
• 5,000 catheter revisions annually
• Estimated revision cost 10,000
• 50,000,000 yearly revision cost

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Catheter Fracture - Midline Insertion
Midline
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Two Piece Catheter (8731)
Pre-attached catheter anchor/connecting pin
Sutureless strain relief sleeve (distal)
Pre-attached proximal strain relief sleeve
Pre-attached pump connector
8711 catheter
8731 Catheter
67
Catheter Insertion Technique

• Paramedian entry
• 1.5-2 cm off midline toward side of pump pocket
• 1 to 1 ½ vertebral levels caudal to dural entry
• Avoid midline insertion
• Shallow angle of insertion, 30 degrees
• Facilitates catheter insertion
• Position catheter just below conus

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Catheter Insertion
30
69
Catheter Insertion
70
Catheter Fracture/Tears

• Pulling the catheter back through the introducer
  needle may shear or create holes in the catheter
• Gently remove stylet with catheter fully
  stretched Using excessive force can produce
  tears in the catheter

71
Expose Lumbodorsal Fascia

• 5-6 cm incision down to fasica
• Leave needle in place to avoid cutting catheter
• Undermine each side to facilitate anchoring

72
Pump Pocket

• Upper quadrant of abdomen 2 inches
  below/parallel to costal margin
• Big enough, but not too big
• AVOID
• incision directly over refill port
• site of current/future surgery
• site of previous radiation
• iliac crest, rib cage
• placing directly beneath beltline

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Tunneling and Anchoring
Back-to-Front
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Strain relief loop of catheter
Anchor at fascial insertion site
75
Anchoring Pump

• Connect catheter to pump and secure
• Coil excess tubing behind pump
• Place pump in pocket and secure with
  non-absorbable sutures
• Suture loop
• Dacron pouch
• Aspirate/inject through CAP to confirm patency

76
Catheter tip
Pump anchored with sutures or pouch
Dural puncture
Paramedian Oblique Entry
V-wing anchor
Loop of excess catheter under pump
5 cm of slack in catheter
Catheter connector which also functions as the
primary anchor
77
Complications

• Infection
• most often occurs at pump pocket
• REMOVE the system
• Post-dural puncture headache
• CSF leak
• Mechanical problems
• Misplaced catheter
• Catheter disconnection
• Catheter migration
• Pump pocket seroma

78
Spinal Opiates for Benign Pain

• Accepted yet controversial
• Mixed reviews and results
• Long-term effectiveness is unclear given the
  non-uniformity of reporting outcomes
• No definitive end-point for therapy

79
Spinal Opiates For Non-Cancer Pain

• PAIN DISTRIBUTION
• Axial lower back pain
• Diffuse bilateral leg pain
• Unilateral leg pain
• failed trial of spinal cord stimulation

80
Spinal OpiatesNon-Malignant Pain

• U.S. experience, 1981-1992
• 14 authors, 156 patients
• 69 (107) good-excellent pain relief
• 75 (126 of 169) with cancer pain had
  good-excellent pain relief

Krames E Spinal Administration of Opioids for
Nonmalignant Pain Syndromes A U.S. Experience
81
Spinal Opiates Non-Malignant Pain

• 120 patients
• 63 (n76) with FBSS or LBP
• Mean age 54.0 11.2 years (28-79)
• Follow-up period
• mean 3.4 1.3 years (0.5 - 5.7 years)

Winkellmuller et al. J Neurosurgery 85458-467,
1996
82
Spinal OpiatesNon-malignant Pain

• Mean morphine dose
• initial 2.7 mg/day (0.3-12 mg/day)
• after 3.4 years 4.7 mg/day (0.3-12 mg/day)
• 28 patients followed more than 4 years
• 64 (n18) constant dosage history
• 36 (n10) increase in morphine dose gt 6mg/day
  after 1 year

Winkellmuller et al. J Neurosurgery 85458-467,
1996
83
Mean Pain Scores

• 74 benefit from therapy
• Avg. pain reduction
• 67 at 6 months
• 58 last follow-up
• 81 improve quality of life
• 92 satisfied

Winkellmuller et al. J Neurosurgery 85458-467,
1996
84
Mean Daily Morphine Dose
Winkellmuller et al. J Neurosurgery 85458-467,
1996
85
Multicenter Review of Spinal Opiates

• Retrospective review of 429 patients
• 66 non-malignant pain
• Physician assessment
• global pain relief scores
• percent pain relief
• VAS scores for pain intensity
• ADL, overall activity level
• Employment

Paice J Pain Symptom Management, 1996
86
Global Pain Relief

• Excellent 52.4
• Good 42.9
• Poor 4.8

Paice J Pain Symptom Management, 1996
87
Changes in ADL

• Increased 82
• No Change 14
• Decreased 4

Paice J Pain Symptom Management, 1996
88
Daily Opiate Dosage

• Mean daily dose, 9.2 mg/day
• Initial dose higher for non-malignant pain
• Gradual linear dose escalation in non-malignant
  pain
• At 24 months, dosages similar in patients with
  non-malignant and cancer pain

Paice J Pain Symptom Management, 1996
89
Conclusions of Multicenter Review

• Nociceptive pain responds best to spinal opiates
• Neuropathic pain responds to spinal opiates but
  may require higher dosages
• Addition of local anesthetics may by synergistic
  in neuropathic pain

90
Prospective Study - Spinal Opiates

• 40 patients with non-malignant pain
• mostly FBSS with gt 3 operations
• Mean duration of pain, 8 9 years (6mos-40yrs)
• 30 (75) had successful screening trial
• minimum of 50 pain reduction by VAS
• Follow-up 6, 12, 18, 24 months
• complete data for 20 patients followed for 2
  years
• Outcome by VAS, CIPI, BDI, MPQ

Anderson V,Burchiel K Neurosurgery, Feb. 1999
91
Results

• VAS for pain and pain coping scores remained
  improved
• CIPI and MPQ scores improved and persisted
• Initial morphine dose 1.96 1.8 mg/day, inc. to
  6.0 7.0 at 3 months, 9.43 8.8 at 15 months
• Device complications, 20

Anderson V,Burchiel K Neurosurgery, Feb. 1999
92
Visual Analog Scores

• Mean initial VAS
• 78.5 15.9 (39-100)
• Percent change in VAS significantly decreased at
  each interval
• Decrease in VAS greatest during the initial 3
  months
• Reduction in VAS remained relatively constant

Anderson V,Burchiel K Neurosurgery, Feb. 1999
93
McGill Pain Scores
Anderson V,Burchiel K Neurosurgery, Feb. 1999
94
CIPI Scores

• CIPI improved for 12-18 months
• Several CIPI subscales showed trends toward
  sustained improvement

Anderson V,Burchiel K Neurosurgery, Feb. 1999
95
Medication Intake

• Daily IT morphine dose ? 25mg
• Mean equianalgesic opioid dose increased
  significantly over time
• initial 1.96 1.75 mg/day
• 24 months 14.59 20.52 mg/day
• Dose escalation most rapid during initial 3
  months
• Oral narcotic intake
• initial 90 (28/30)
• 24 months 30 (6/30)

96
Spinal Opiates for Benign PainMaron J, Loeser J
The Clinical Journal Pain, 1996

• Data insufficient to permit formal analysis
• The proper role of intraspinal opioids in the
  treatment of non-malignant pain cannot be
  determined from the existing literature
• Spinal opiates for benign pain should be
  considered experimental
• All patients who receive such therapy should be
  part of a clinical protocol

97
Unresolved Issues

• How should outcome be measured?
• Management of tolerance
• Question of neurotoxicity
• Development of hyperalgesia
• Indefinite requirement for medical care

98
The Dilemma of Outcomes

• A lack of consensus complicates the
  interpretation of many if not the majority of
  efficacy studies

99
The Bottom Line

• There can be no substitute for sound clinical
  judgement based on a detailed assessment of each
  patient !

100
Conclusions

• Intraspinal opiates can be safely used in
  patients with non-malignant pain syndromes
  without fear of drug abuse
• Intraspinal opiates are effective in reducing
  pain in carefully selected patients with
  non-malignant pain syndromes including FBSS
• Most patient with non-malignant pain express
  satisfaction with the therapy
• Patients experience improvements in ADL
• Whether intraspinal opiates improve return to
  work rates in patients with FBSS remain
  unresolved

101
Conclusions

• Spinal opiates are effective in patients with
  pain due to cancer
• Long term issues regarding tolerance,
  neurotoxicity, etc. are generally irrelevant
• Choice of device depends on anticipated life
  expectancy