Download Adjuvant pain medication

Adjuvant Pain Treatments
Elizabeth Whiteman, M.D.
Goals and Objectives
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Understand the physiology of pain
Assess for different causes of pain
Pain in special populations
Use of adjuvant drugs
Non pharmacologic methods
Non physical causes of pain
Adjuvant medications
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Acetaminophen and non opioids
Anti-inflammatory
Antidepressants
Anti seizure medication
Anticholinergics
Local anesthetics
Corticosteroids
Other: calcitonin, bisphosphonates
Muscle relaxants
NMDA inhibitors
• Adjuvant medications can be used alone or in
conjunction with other pain medication
(opioids)
• Medication can be titrated to pain relief and
avoid side effects
• A patient may benefit most from adjuvants in
pain symptoms more neuropathic or visceral
Case 1
Mary is a 60 year old female with a history of
metastatic breast cancer. She has had increased
pain in her Right flank , radiating around her
chest. She is on Morphine SR 15mg BID. But the
pain is getting worse. She describes it as sharp.
Differential Diagnosis?
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Bone metastasis spine
Nerve impingement
Herpes Zoster
Localized bone metastasis
Fracture
• You examine her and there is no localized rash
or blisters. She has hypersensitivity to touch but
no localized pain.
• X ray is negative for rib fracture, shows
osteopenic bone.
• MRI T spine shows Mets to her T spine and
compression fracture with nerve impingement
Treatment options?
Acetaminophen
• Acetaminophen can be used for mild to
moderate pain .
• 650mg-1000mg q6hr. Max dose 4000mg/24 Hr.
• Acetaminophen IV has been effective in
immediate post op pain control. Only approved
for Post op use now. Less need for narcotics.
Anti-inflammatories
• NSAIDS and Cox 2 inhibitors
▫ Can be used for inflammation, bone pain and as
an adjuvant to narcotics
▫ Risk vs. benefit in thrombotic risk for CAD or CVA
patients
▫ Risk GI bleed or renal insufficiency, inhibit
platelet aggregation
▫ Poor choice for patients with poor PO intake and
risk GI side effect.
▫ Consider GI prophylaxis
Corticosteroids
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Often useful as adjuvant in pain control
Bone metastasis
Increased intracranial pressure
Nerve impingement
Acute internal inflammation (visceral pain)
• Also caution for GI bleed, glucose control and
Altered mental status and delirium especially in
elderly or patients with neurologic dysfunction
Antidepressants
• Tricyclic Antidepressants( amitryptiline,
nortriptiline, desipramine)
▫ For neuropathic pain
▫ High side effects- Anticholinergic
▫ Use with caution in elderly, often sedating
• SSRI’s, SNRI’s (venlafaxine, duloxetine)
▫ Can be used as adjuvant medication
▫ Duloxetine is approved for diabetic neuropathy (off
label for post herpetic neuralgia)
Anticonvulsants
• Anti seizure medications
▫ Carbamazepine, phenytoin
 Monitor LFT
 Monitor CBC with carbamezepine (risk aplastic
anemia)
 Risk for sedation
▫ Pregabalin (lyrica)
 Approved for diabetic neuropathy and post herpetic
neuralgia
 25-100mg tid dosing
 Need to renal dose
Gabapentin
• Good results for neuropathic pain
▫ Sharp shooting pain, numbness, burning
• Usual effective dose 900-3600mg/day
in 3 divided doses
• Slow and gradual dose increase
▫ 100mg QD to start, increase by 100mg every 3-5
days as tolerated
▫ 100mg bid-100mg tid etc…
Anticonvulsant side effects
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Monitor for dizziness
Altered mental status
Lethargy
Anorexia or nausea
Alpha-2 Receptor Agonists
• Clonidine- tablets, patch, epidural
▫ Post op use showed decreased narcotic
consumption
▫ Increased time to next analgesic need
▫ Risk of sedation and bradycardia, but no increased
risk hypotension
▫ Side effects dizziness, CNS depression, xerostomia
▫ Rebound hypertension, withdraw gradually
Antispasm drugs
May help in muscle spasm eg: MS, spinal cord injuries
• Muscle relaxants
▫ May be helpful in muscle spasm
 baclofen, carisoprodol, cyclobenzaprine, methocarbamol
 Monitor for side effects: sedation, confusion
• Benzodiazepines
▫ clonezepam, lorazepam, diezepam
▫ Risk for sedation, confusion
NMDA Receptor Antagonists
• Methadone
• Ketamine
▫ -Opioid sparing
▫ Studies show reduced opioids need
▫ Start 10-15mg q6hr PO or 0.04mg/hg/hr iv
(max 0.3mg/kg/hr)
▫ Side effects dizziness, hallucinations
Parental lidocaine
 Can be an effective agent to treat severe pain
especially when neuropathic and thus has potential
to improve a patient’s quality of life
 side effects are short lived (usually lightheadedness, nausea, phlebitis at site of infusion)
with no untoward long term effects
 Use of opioid medications can often be reduced,
minimizing their side effects
 Start with a lidocaine bolus/loading dose, then start
a continuous IV or SC infusion, the goal is the lowest
dose possible that still controls the pain
Non Pharmacologic Strategies
• Topical anesthetics
▫ Ice, heat ,massage
▫ Heated rubs (BenGay, icy hot etc.)
▫ topical NSAID creams
▫ Lidocaine Patch
▫ Capsaicin cream
Non Pharmacologic
• Physical interventions
▫ Heat/cold
▫ Massage
▫ Repositioning, bracing
▫ Acupuncture/Acupressure
▫ Physical therapy
Non pharmacologic Therapy
• Other
▫ Relaxation
Guided imagery
Distraction
▫ Cognitive therapy
▫ Support group
▫ Spiritual
Anticancer Therapies
• Radiation
• Chemotherapy
• Bisphosphonates
▫ Pamidronate, zolendronate, ibandronate
▫ Full benefit usually takes 7-14 days
• Surgery
• Radiopharmaceutical agents
▫ Stronium 89
Calcitonin/ Bisphosphonates
• Calcitonin not recommended for pain relied in
metastatic disease
• Bisphosphonates
▫ reduce bone absorption and formation by
inhibiting adhesion of tumor cells and inhibiting
osteoclast function
Case
Mary’s MRI had metastatic lesions in her ribs and
t spine. Her pain is still not controlled on A PCA
pump and she is very sleepy and delirious when
her basal PCA is increased .
Treatment options??
steroids
bisphosphonates
NSAIDS
radiation treatment
• After treatment with all the above Mary
completes her radiation treatment in the
hospital and pain is stable on MS Contin 60mg
bid and Decadron 4mg po bid
• She is discharged to home on hospice and lives 2
more months with pain controlled.
References
• Chang VT, Jain S, Chau C, Update in cancer pain
Syndromes, Journal of Palliative med 2006;9(6):1414-1434
• Foley KM, Acute and Chronic cancer pain syndromes In:
Doyle D, Hank GW, Cherney N et al. Oxford Textbook of
Palliative medicine, 3rd edition, New York, NY, Oxford
University Press: 2005.
• Janjan N, Lutz S, Bedwinek J et al. Therapeutic Guidelines
for the treatment of Bone Metastasis: A report from the
American College of Radiology, Appropriateness Criteria
Expert Panel, Journal of Palliative Medicine, 2009;12(5):
417-426.