Transcript Pain Management

Pain Management
Saurabh Narkhede
10/23/2013
Clinical Seminar II: Disease State Presentation
Objectives
 Review description of pain types
 Review pathophysiology, signs and symptoms and
diagnosis of pain
 Review non-pharmacological and pharmacological
treatment options
 Discuss pharmacist role in pain management
Definition of Pain
 “Pain is an unpleasant sensory and emotional
experience associated with actual or potential tissue
damage, or described in terms of such damage.”-The
International Association for the Study of Pain, 1979
 “Pain is whatever the experiencing person says it is,
existing whenever he/she says it does” -Margo McCaffery
 Chronic pain is defined as “a pain that persists beyond
normal tissue healing time, which is assumed to be
three months” -The International Association for the Study of Pain, 1979
Prevalence/Epidemiology
 About 9 in 10 Americans regularly suffer from pain
 Most common reason why patients seek medical
attention
 Acute pain: about 25 million Americans suffer acute
pain due to injury or surgery each year
 Chronic pain: one third of Americans experience
chronic pain at some point in their lives
Prevalence/Epidemiology
 Elderly population is affected the most
 Pain is undertreated in facilities
 Seriously ill hospitalized patients: 50% report pain
 15% have moderate to severe pain 50% of time during
hospitalization
 15% of patients are dissatisfied with overall pain control
Types of Pain
 Nociceptive:
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Direct stimulation of intact nociceptors
Classified as visceral or somatic
Respond to stimuli
Described as sharp, aching, throbbing
 Neuropathic:
 Structural damage and nerve cell dysfunction in the peripheral
or central nervous system
 Any process that causes damage to nerves can cause
neuropathic pain
 Described as burning, shooting, electrical shock-like, tingling
Classification of Pain
 Acute
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Sudden onset
Identifiable event (surgery, acute illness, trauma, labor, medical procedure)
Resolves within days to weeks
Typically nociceptive
 Chronic
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Present for at least 3 months or longer
No identifiable cause
Negative effects on QOL
Nociceptive and/or neuropathic
 Cancer
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Includes both chronic and acute pain
Multiple causes
 Disease itself, treatment, diagnostic procedures
Nociceptive Pain
Pathophysiology
 Nociceptive Pain
1)
2)
3)
4)
5)
6)
Stimulation of nociceptors and release of bradykinins, potassium ions,
prostaglandins, histamine, leukotrienes, serotonin, and substance P
Afferent nerves transfer the signal to spinal cord’s dorsal horn and
release glutamate, substance P, and calcitonin gene-related peptide
The signal reaches the brain via complex array of at least five ascending
spinal cord pathways (spinothalamic tract; thalamus is thought as relay
center for pain)
Pain perception
Modulation (body activates endogenous opiate system and release
enkephalins, dynorphins, and B-endorphins, which also inhibits synaptic
pain transmission at the dorsal horn)
Adaptive inflammation means body’s shifting from preventing tissue
damage to promotion of healing (decrease pain threshold and increase
sensitivity to promote healing)
Pathophysiology
 Neuropathic
1) Due to nerve damage
 Postherpetic neuralgia, diabetic neuropathy
 Functional Pain
1) Due to abnormal operation of nervous system
 Fibromylagia, irritable bowel syndrome, sympathetic induced
pain, tension headaches, noncardiac chest pain
Signs and Symptoms
 Joint Commission requires pain be treated as a “vital
sign”
 Subjective to each patient
 Symptoms: sharp, dull, shock-like, aching, tingling,
shooting, radiating, fluctuating in intensity, localized or
generalized
 Non-diagnostic symptoms: hypertension, tachycardia,
diaphoresis, mydriasis, pallor
 Neuropathic pain
 Symptoms: burning, shooting, numbing, tingling, or
electrical sensation
Diagnosis
 Pain is best diagnosed based on patient description
and history
 Pain assessment tools
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Wong-Baker FACES Pain Rating Scale
0–10 Numeric Pain Rating Scale
Pain Quality Assessment Scale (PQAS)
Patient Interview using PQRST Characteristics
Non-pharmacological
Treatment
 Heat
 Aromatherapy
 Ice
 Guided imaginary
 Massage therapy
 Laughter
 Physical therapy
 Music
 Transcutaneous electrical
 Biofeedback
nerve stimulation (TENS)
 Spinal cord stimulation
(SCS)
 Hypnosis
 Acupuncture
Pharmacological Treatment
NSAIDs
MOA: Inhibits Cox-1 and Cox-2 and inhibit formation of prostaglandins
BBW: Increase risk of
serious cardiovascular
thrombotic events,
myocardial infarction and
stroke, which can be fatal.
Drug
Usual dosing
Aspirin
325-650mg q4hr max 4
grams
Ibuprofen (Advil, Motrin)
400-800mg q6-8h max 3.2
grams
Naproxen (Aleve, Anaprox)
220-550 q8-12hr
Contraindicated for treatment Diclofenax (Voltaren)
of perioperative pain in
Indomethacin (Indocin)
setting of CABG.
Piroxicam (Feldene)
Increase risk of GI adverse
events (bleeding ulceration,
and perforation of
stomach/intestines)
Avoid in pregnancy
50-75mg BID
25-50mg q8-12hr
10-20mg QD
Ketorolac (Toradol)
10-20mg q6-8h max 40mg
Meloxicam (Mobic)
7.5-15mg QD
Etodolac (Lodine)
300-500mg q6-8hr
Nabumetone (Relafen)
1000-2000mg QD
Celecoxib (Celebrex)
100-200 BID
NSAIDS
Notes
Side effects
 Dyspepsia
 Heartburn
 Increase blood pressure
 GI irritation/bleeding
 Photosensitivity
 Tinnitus (aspirin overdose)
 Take with food to decrease
nausea
 Ketorolac maximum 5 days
of duration
 Celecoxib is highly selective
toward COX-2
 Can be used with
misoprostol, PPIs, H-2
antagonists to decrease GI
irritation
acetaminophen (Tylenol, Ofirmev)
 Usual dose: 325-650mg q4-6hr max 4 grams/day
 Available in combination with hydrocodone, codeine,
oxycodone, tramadol for moderate to severe pain
 Ofirmev- IV formulation; used in inpatient setting to enable
lower opioid doses
 Side effects: Rare but overdose can lead to hepatic damage
 Overdose antidote: N-acetylecysteine
 PO LD: 140mg/kg; then 70mg/kg q4hr for 17 doses
 IV: 150mg/kg over 1 hr; then 50mg/kg over 4 hr; then 100mg/kg
over 16 hours
Opioids
 MOA: Mu receptor agonist
 BBW: Schedule II; monitor for signs of misuse, abuse,
and addiction; risk of fatal respiratory depression.
 Contraindications: respiratory depression, severe/acute
asthma, hypercarbia, and paralytic ileus
 Do not exhibit a ceiling effect with increasing dose…
NO MAXIMUM DOSE
 But recommended to rotate high doses with other opioids
to reduce tolerance
Drug
Strength
Morphine (MS Contin, Avinza, Kadian,
Oramorph SR, Roxanol)
IR: 10-30mg q4hr prn
ER: 15-200mg q8-12hr
Hydromorphone (Dilaudid)
IR: 2-4mg q4-6hr prn
Oxycodone (OxyContin)
IR: 5-15mg q4-6hr prn
ER: 10-30mg q12hr
Oxymorphone (Opana)
IR: 5-10mg q4-6hr prn
ER: 5-30mg BID
Fentanyl (Duragesic, Actiq, Abstral,
Fentora)
Patch: 12-100mcg/hr q3days
*Chronic pain management only
Meperidine (Demerol)
50-150mg q2-4hr
*Avoid in chronic pain management
Methadone (Dolophine)
2.5-10mg q8-12hr
Drug
Strength
Hydrocodone + APAP (Lorcet, Lortab,
Vicodin, Norco)
2.5-10mg with APAP
Codeine + APAP (Tylenol #2, 3, 4)
15-120mg q4-6hr prn
Miscellaneous Opioids:
MOA: Mu-receptor agonist as well as 5-HT and NE reuptake inhibitor
Drug
Tramadol (Ultram, Ryzolt)
Tramadol + APAP (Ultracet)
IR: 50-100mg q4-6hr prn max 400mg/day
ER: 100mg QD max 300mg/day
Tapentadol (Nucynta)
IR: 50-100mg q4-6hr prn max 700mg/day
ER: 50mg q12hr max 500mg/day
Side Effects
• All opioids share same side effect profile
• Most resolve after 24-72 hours after steady state is reached
• Except constipation
Adverse Effects
Constipation
Pruritis
Myoclonus
Respiratory depression
Urinary retention
Sedation/cognitive impairment
Nausea and vomiting
Delirium
Opioid Allergy
 True opioid allergy is rare (<1%)
 Adverse effects of opioids are often mistaken for
allergic reaction
 IF true allergy:
 Cross-reactivity between classes (avoid medications in
same class)
 Morphine-group: morphine, oxymorphone, codeine,
hydromorphone, oxycodone, nalbuphine, butorphanol,
levorphanol, pentazocine
 Meperidine-group: meperidine, fentanyl, alfentanil,
remifentanil
 Methadone-group: methadone, propoxyphene
Equianalgesic Table
Opioid
IM/IV
Oral
(mg)
(mg)
10
30
Not Available
20
1
10
Hydromorphone
1.5
7.5
Fentanyl
0.1
Not Available
Meperidine
75
300
Not Available
30
130
200
Morphine
Oxycodone
Oxymorphone
Hydrocodone
Codeine
Patient Controlled Analgesia
(PCA)
 Patients self administer a preset
dose of IV opioids via an infusion
pump
 Provide better pain control and
avoids overdosing
 No difference between side effects
from PCA or traditional route
Antidote
 S/S of acute opioid overdose
 Somnolence, respiratory depression with shallow
breathing, cold and clammy skin, constricted pupils
 Treatment: Naloxone (Narcan)
 MOA: Opioid receptors antagonist
 Dose: 0.4-2mg q2-3 mins or IV infusion at 100ml/hr
(0.4mg/hr)
 Cause withdrawal syndrome: pain, anxiety, trouble
breathing, tachycardia
 Alternative: naltrexone IV (Vivitrol)
Opioid Addiction
 FDA approved:
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Methadone
Buprenorphine (Subutex)
Buprenorphine + Naloxone (Suboxone)
Naltrexone (Vivitrol)
Muscle Relaxant/Spasticity Agents
Drug
Dosing
Comments
Carisoprodol (Soma)
250-350mg QID prn
C IV
Baclofen (Lioresal)
5-20mg TID-QID prn
Cyclobenzaprine (Flexeril)
5-10mg TID prn
Anticholinergic effects
Metaxalone (Skelaxin)
800mg TID-QID prn
Cognitive impairment,
hepatotoxicity
Methocarbamol (Robaxin)
1500-2000mg QID prn
Hypotension
Tizanidine (Zanaflex)
2-4mg q6-8hr prn
Chlorzoxazone
250-760mg TID-QID prn
Urine discoloration (orangered)
Diazepam (Valium)
2-10mg TID-QID prn
C IV
• All muscle relaxant cause excessive sedation, fatigue,
dizziness, and confusion
• Avoid concurrent use of alcohol, sleeping pills, antihistamine,
sedatives, and tranquilizers
Neuropathic Pain
Drug
Dosing
Comments
Pregabalin (Lyrica)
75-150mg BID
C IV
Adjust for renal function
S/E: dizziness, somnolence,
euphoria, blurred vision, peripheral
edema, weight gain
Gabapentin (Neurontin)
600-3600mg/day
Same as Lyrica except not C IV
Duloxetine (Cymbalta)
30-60mg/day
SNRI
Amitriptyline (Elavil)
10-50mg qHS
TCA
Topical Agents
Drug
Notes
Lidocaine 5% patch
(Lidoderm)
Apply up to 3 patches for up to 12 hrs/day
Can cut into smaller pieces
Capsaicin (Zostrix)
Apply TID-QID
Diclofenac topical
(Voltaren gel)
Apply TID-QID
Remove for MRI
Others: OTC menthol, methylsalicylate, camphor, and trolamine salicylate
Special Population
 Pregnancy
 DOC: Tylenol
 Opioids are pregnancy category C except oxycodone is B (use
when benefit > risk and travels through breast feeding)
 Avoid NSAIDs
 Elderly
 DOC for mild to moderate pain: Tylenol
 Opioids titrate up slowly due to risk of hepatic and renal
impairment
 NSAIDs increase risk of stomach irritation and GI bleeding and
increase risk of serious cardiovascular event
Pharmacist Role
 Responsibilities:
 Interviewing patient regarding pain and assessing need of
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pain medications
 Assessing between addiction and actual need
Dispensing of medications
Counseling patient on medications and its adverse effects
Proper conversion of medications (opioids)
Follow up on pain relief
Counseling on proper disposing of medications and
possible consequences of drug diversion
References
 Baumann TJ, Strickland J. Pain Management. In: DiPiro JT, Talbert
RL, Yee GC, Matzke GR, Wells BG, Posey LM, eds.
Pharmacotherapy: A Pathophysiologic Approach. 7th ed. New
York, NY: McGraw-Hill; 2008:989-1003.
 Joint Commission on Accreditation of Healthcare Organizations
National Pharmaceutical Council. Pain: current understanding of
assessment, management, and treatments. 2001:1-92
 Fudin J. Opioid Pain Management: Balancing Risks and Benefits.
Drug Topics. 2011:46-58.
 Drugs for pain. Treat Guidel Med Lett. 2013;11(128):31-42.
 Shapiro K, Brown SA. Pain. RxPrep Course Book. 2013: 416-439.