2. ความปวด ***** PAIN
An unpleasant sensory and emotional
experience associated with actual or potential
tissue damage, or described in terms of such
damage
ประสบการณ์ที่ไม่สบายกาย ไม่สบายใจ ที่เกิดจากการ
บาดเจ็บของเนื้อเยื่อหรือศักยภาพที่จะทาให้มีการบาดเจ็บของ
เนื้อเยื่อ หรือประหนึ่งว่ามีการบาดเจ็บ
3. FACTS ABOUT CANCER PAIN
Frequency of occurrence varies with ;
• stage of the disease
• primary site of the tumor
Moderate or severe pain occurs in 30 - 40%
of the patients at the time of diagnosis and
60 - 100% with advanced cancer
Most cancer patients have more than
one pain
5. CAUSES OF PAIN
1. Due to tumor involvement 78%
• bone, nerve, soft tissue, viscera
2. Associated with treatment 19%
• diagnosis and staging procedures
• surgery
• chemotherapy; mucositis, phlebitis,
tissue necrosis, myalgia, arthralagia
• radiotherapy; mucositis, neuropathy,
myelopathy
6. CAUSES OF PAIN
3. Due to general illness but not cancer (10%)
• constipation
• pressure
• gastric distention
• reflux esophagitis
• bladder spasm (with catheterization)
• musculoskeletal pain
• thrombosis and embolism
• mucositis
• post herpetic neuralgia
4. Unrelated to cancer or its treatment(10%)
14. KEY TO
SUCCESSFUL PAIN MANAGEMENT
• Comprehensive pain assessment and diagnosis
• Formulate treatment plan
• View the treatment as a dynamic process
• Explanation
• Rx of the underlying cause
• Elevation of the pain threshold
• Interruption/destruction/stimulation of the pain
pathways
• Change of life style
15. KEY TO
SUCCESSFUL PAIN MANAGEMENT
• WHO guidelines are the
mainstay
• But !!! Not the only solution
• Talk to the patient and care-
givers will
• Reinforce patient autonomy
• Increase pain tolerance
• Improve coping skills
• Allay misconceptions
16. HOW TO ACHIEVE MAXIMUM BENEFIT
FROM ANALGESIC LADDER
• Choose the drug according to severity of pain
• Only one drug in a class
• Combine one drug from each of different classes
• Multimodal analgesia – polypharmacy
• Use coanalgesics or adjuvants
17. HOW TO ACHIEVE MAXIMUM BENEFIT
FROM OPIOIDS
• For opioid naive patient with moderate pain
• Codeine 90-120 mg/day
• Tramadol 150-200 mg/day
• Morphine 15-20 mg/day
• Oxycodone 10 mg/day
• Titration for patient with severe pain
• Morphine immediate release (MIR)
• Morphine sustained release (MST)
• Big dose tramadol?
• Fentanyl TTS
18. HOW TO ACHIEVE MAXIMUM BENEFIT
FROM OPIOIDS
• Start with any appropriate route of administration
• Oral MIR 10 mg q 6 h (60 mg/day)
• IV bolus titration
• IV PCA
• Rescue dose 16% of total daily dose
• Increase dose by 33-50% or rescue dose + in
suitable interval
• Switch to oral dose of MST or Fentanyl TTS
19. BREAKTHROUGH PAIN, INCIDENTAL
PAIN AND RESCUE ANALGESIC
• Incidence 19-95%
• Medications:
• MIR: MSS, tablet
• Tramadol
• Dose 10-15% of total daily dose
• Mismatch between breakthrough pain profile and opioid
pharmacokinetics:
• Methadone
• Various routes of administration; IV, nasal, sublingual,
effervescent morphine, oral transmucosal fentanyl
20. HOW TO ACHIEVE MAXIMUM BENEFIT
FROM OPIOIDS
• Aware of the inter- and intra-individual response to
opioids
• Problematic start!!!!
• Sedation
• Nausea
• Patients with excruciating pain
• Fast titration
• Test dose IV morphine
• Re-evaluate the pain syndrome
21. HOW TO ACHIEVE MAXIMUM BENEFIT
FROM OPIOIDS
• Patients with poor respond;
• Wider opening therapeutic
window by aggressive side
effects treatment
• Opioid rotation
• Coanalgesics or adjuvants
• Non-pharmacological
approaches
23. PAIN ASSESSMENT
• Location of all the pain
• How the pain feels
• Intensity of the pain
• When, frequency, duration
• What ease the pain, what worsen
the pain
• Medications taking
• Side effects of pain medications
• Quality of life issues
•Pain diary!
24.
25. PAIN ASSESSMENT
• Chronicity: Acute vs Chronic pain
• Pain intensity
• Pathophysiology:
somatic vs. visceral
nociceptive vs. neuropathic
• Course of the disease: continuous,
breakthrough, incident pain.
• Pain syndrome: brain metastasis,
bone pain
26. CHRONICITY
Acute pain Chronic
pain
Onset well-defined ill-defined
Cause acute injury or
illness
chronic
progress
Duration days/weeks
predictable
months/years
unpredictable
Physiologic
al
sympathetic over
activity
no sympathetic
over activity
27. Acute pain Chronic
pain
Affective anxiety depression
Cognitive meaningful meaningless
Behavioral inactivity until
recovery
changes in life
style
changes in
functional
ability
withdrawn
Treatment cause
temporary
analgesics
supportive
regular
analgesics
28. CATEGORAL SCALES
• Verbal rating scale (VRS)
(verbal descriptor scale)
• 2 – 7 words
None Mild Moderate Severe
• Pain relief
None Slight Moderate Good Complete
33. PATHOPHYSIOLOGY
• Nociceptive ( somatic and visceral )
• constant and well localized
• aching, throbbing, gnawing
• vague in distribution and quality, deep, dull, aching,
dragging, squeezing, pressure-like
• Neuropathic
• may be constant, steady, and spontaneously
maintained, intermittent, shock-like, shooting,
lancinating, electrical, burning, tingling, numbing,
pressing, squeezing, and itching
• dysesthesia, hyperalgesia, allodynia, hyperesthesia,
hyperpathia
34. NEUROPATHIC PAIN
• Hardest mechanism to treat
• Diagnose straightforward: nerve or
dermatome distribution, no local tenderness
but referred
• Two types
• Mixed: nociceptive/neuropathic due to tumor
invasion or compression of nerve pathway;
brachial, lumbosacral plexus, chest wall invasion,
spinal cord compression
• Pure (Deafferentation): no nociceptive element;
PHN, post-thoracotomy syndrome, phantom pain
35.
36.
37.
38. BONE PAIN
• Most common cause of pain in advanced
cancer
• Most common malignancies metastasize to
bone: breast, prostate, lung, kidney, thyroid
• Common problems: chronic bone pain, pathologic
fracture, hypercalcemia
• Treatment includes: NSAIDs, opioids, radiotherapy,
Strontium-89, bisphosphonate, corticosteroids, calcitonin.
• Early Orthopedic consultation and treatment is
important
41. PRINCIPLE OF ANALGESIC USE
• Define the nature of pain
• Maximize the current regimen
• Understand the drug Pharmacology
• Speed of onset and duration of action
• Management of side effects
• Beware of the drug interactions
• Emphasize patient education
43. WHO ANALGESIC LADDER (1992--)
Non-opioid
+ Adjuvants
Opioid for
mild to moderate pain
+ Non-opioid + Adjuvants
Opioid for
Moderate to severe pain
+ Non-opioid + Adjuvants
Pain
Pain persist
Pain persist
Freedom from
cancer pain
45. ESSENTIAL CONCEPTS IN THE WHO
APPROACH TO DRUG THERAPY
•By the mouth
•By the clock
•By the ladder
•For the
individual
•With attention
to detail
46. PRINCIPLES OF ANALGESIC USED
• Administer on strict schedule to
prevent pain, not PRN
• Give instructions for treatment of
breakthrough pain
• Following analgesic ladder
• Review & assess
47. GENERAL
RECOMMENDATIONS
• Oral medications should be used as
the first line approach.
• Any proposed systemic regimen must
be individualized.
• There is no predetermined maximum
dose of an opioid.
• Dose titration may be required
periodically.
49. NAUSEA
• Moderate to severe 8.3 – 18.3%
• Direct effect of opioids on CTZ
• Decrease quality of life, limit food
intake
• Other underlying conditions; electrolyte
imbalance, dehydration, brain metastasis,
intestinal obstruction, ileus, chemotherapy,
tumor of the GI, constipation, infection,
blood poisoning, kidney problems, anxiety,
etc.
50. NAUSEA
• Usually subside within few days
• Treatment;
• Metoclopramide ( block in GI tract and CTZ)
• Butyrophenones (haloperidol, droperidol) (at
CTZ)
• Phenothiazine (CTZ, GI, vestibular)
• Antihistamine (dramamine,hydroxyzine) (H1
blockade and VC)
• Hyoscine, scopolamine (VC and GI)
• Ondansetron (5HT3 in GI and CTZ)
• Benzodiazepine (lorazepam) GABA agonist
51. CONSTIPATION
• The most troublesome, almost everyone is involved,
will not develop tolerance
52. TREATMENT OF CONSTIPATION
• Stimulant laxatives
• Senokot 1 tab hs – 4 tab tid orally
• Dulcolax 1 tab hs – 3 tab tid orally
• Bulk-forming laxatives
• Metamucil 1 tsp in 8 oz water OD – tid
• Bran
• Saline or osmotic cathartics
• MOM 15 – 40 ml OD – bid
• Magnesium citrate solution 240 ml OD
53. CNS EFFECTS
• Aggravating factors;
• High doses opioid
• Psychoactive drugs
• Renal failure
• Slow down of cognitive function, sedation,
hallucination and delirium, fluctuation of
consciousness, change in sleep-wake cycle,
agitation, myoclonus.
• Improve spontaneously
54. CNS EFFECTS
• Role of M-3-G
• Management;
• Opioid rotation
• Dose reduction
• Circadian modulation
• Hydration
• Psychostimulants
• Other drugs; haloperidol, midazolam, baclofen,
clonazepam,clonidine
56. ADJUVANTS
DRUGS
- Anticonvulsants
- Antidepressants
- Local anesthetics
- Corticosteroids
- Antihistaminics
- Muscle relaxants
- Psychostimulants
- Drug action on bone
INDICATIONS
- neuropathic pain
- neuropathic pain
- neuropathic pain
- multiple
- coanalgesic, antiemetic
- muscle spasm
- opioid sedation
- bone pain
57. ANTIDEPRESSANTS
• Used in neuropathic pain ; several studies in
Diabetic neuropathy, Post-herpetic neuralgia,
phantom limb pain, migraine headache
• Reduce insomnia and anxiety
• 1-2 weeks lag time for clinical effects
• Start 10-20 mg hs
• Escalated 4-5 day intervals to doses 100- 150
mg
• Abrupt escalation not recommended
82. PLEA OF A
PATIENT
When I come to you in pain
’This for comfort and not for gain
Should I need a narcotic
Lebel me not a drug addict
And when the pain is phenomenal
Don’t forget the non-steroidal
With the H2 blocker
or anti-ulcer
83. PLEA (คาขอร้อง)OF A
PATIENT
And if it’s time for the adjuvants
Do remember the antidepressants
Seek the cause of my pain
And ponder not if I feign
So when the pain fills me with dread(น่ากลัว)
Please don’t say it is in my head
When it’s time for eternity
Allow me to leave with dignity