Post on 21-Jan-2017
PAIN MANAGEMENT IN CANCER
• Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage
• Somatopsychic phenomenon modulated by
Patients moodPatients moraleMeaning of pain for the patient
• 75% of advanced cancer patients experience pain
• One third has single pain• One third has 2 pain• One third has 3 or more pain
pain
psychological
Spiritual
Social
Physical
PAIN MANAGEMENT
• Evaluation• Multidimensional process
• Begins with locating the pain• ‘where exactly is your pain?’• Duration
Characteristics
• Palliative factors• Provocative factors• Quality• Radiation• Severity• Temporal factors
Causes of pain
• Cancer
• Treatment-mucositis
• Debility-constipation, muscle tension
• Concurrent disorder-spondylosis, osteoarthritis
Mechanism
• Functional• Somatic muscle tension pains-tension head
ache, cramp• Visceral-distension, colic
• Pathological• Nocioceptive-tissue distortion or injury
• Neuropathic-compression or injury
• Causes • Cancer-
nerve compression or infiltrationPlexopathySpinal cord compressionThalamic tumor
• Treatment-surgical incision pain phantom limb pain
peripheral neuropathy brachial plexopathy
• Debility-post herpetic neuralgia
• Concurrent disorder-diabetic neuropathy, post stroke pain
AGGREVATING FACTORS
• Discomfort boredom• Insomnia mental isolation• Fatigue social abandonment• Anxiety• Fear • Anger• Sadness• depression
DECREASED• Relief of other symptoms • Sleep • Understanding• Companionship• Creative activity• Relaxation• reduction in anxiety• elevation of mood• drugs
managementModification of
pathological process
analgesics
Non-drug methods
psychological
Interruption of pain pathways
Modification of way of life and
environment
• Modification of pathological process-Radiation therapyHormone therapyChemotherapysurgery
Non-drug methods-massage, heat pads
Psychological-relaxation, cognitive behavioral therapy,
• Interruption of pain pathways local anaesthesia neurolysis-chemical(alcohol, phenol)
cryotherapy thermocoagulation
neurosurgery-cervical cordotomy
• Modification of way of life and environment• Avoid precipitating activity• Immobilisation of painful part-cervical collar,
slings, surgery• Walking aid
ANALGESICS
• Non-opioid• Opioid• Adjuvant
• Principles governing the analgesic use• By the mouth• By the clock-persistent pain needs preventive
therapy• By the ladder-if after optimising the dose of
drug fails to relieve, move up the ladder• Individualised treatment-right dose is the one
which relieve the pain• Use of adjuvant drugs-relieve pain in specific
situation
Strong opioid+non-opioid±adjuvant
Weak opioid+non-opioid±adjuvant
Non-opioid ±adjuvant
Non opioidParacetamol,NSAID
OpioidsCodeine(weak)
Morphine(strong)
AdjuvantSteroids, anti
depressants, anti-epileptics, anti-
spasmodics, muscle relaxants
NON-OPIOID ANALGESICS
• Paracetamol n NSAIDs• Paracetamol-anti-pyretic analgesic inhibits
COX in CNS• Lack anti-inflammatory effect• Undesirable effect uncommon• Does not cause gastritis• Does not affect plasma uric acid• No effect on platelet function
NSAIDs
• Pain associated with inflammation-soft tissue infiltration, bone metastasis
• Non selective Inhibition of COX
• Its prolog use is limited by its adverse effect
• Gastritis• Antoganise urocosuric drugs• Salt and water retension• Renal failure and interstitial nephritis• Platelet dysfunction• Aspirin may cause tinnitus and deafness
WEAK OPIOIDS
• Codeine, dextroprpoxyphene, dihydrocodeine, tramadol
• Codeine is 1/10 as potent as morphine• More constipating than morphine• Tramadol is 1/10 to 1/5 as potent as morphine• Dual mechanism of action partly via opioid
receptor partly by inhibiting PRE SYNAPTIC reuptake of 5-HT and NA
• Less constipating• More effective in neuropathic pain than
morphine• Lower seizure threshold• TCA and SSRIs
Strong opiods
• Morphine, dimorphine, methadone• Oral morphine(tablets and aqeous solution)
• Guidelines for starting morphine
• Indicated in patients in patients who does not respond to optimised combined use of non-opioid and weak opioid
• Start with 10mg q4h or m/r 20-30mg q12h
• Lower dose 5mg q4h in elderly and frail and in renal failure
• If patients requires two or more p.r.n dose in 24h increase dose by 30-50% every 2-3 days
• Titrate till pain relieves or intolerable effects limits further escalation
• Add drugs which relieves its adverse effects
• Anti emetic haloperidol 1.5mg stat and sos, metaclopramide
• Prophylactically prescribe laxative to prevent constipation
• Warn all patients about initial drowsiness
• For outpatients write out drug regimen in detail time, amount to be taken and arrange for follow up
• Ordinary morphine and modified release morphine(m/r)
• Once we get the stable q4h ordinary morphine dose
• Replace it with q12h m/r morphine(3 times q4h dose)
• Continue to give p.r.n ordinary morphine 1/6 th of total daily m/r dose
Adverse effects
• Gastric stasis- epigastric fullness, flatulence, nausea, anorexia, hiccup-metoclopramide
• Sedation• Cognitive failure-haloperidol
• Myoclonus and Hyperexcitability -abdominal muscle cramps, whole body allodynia, symmetrical jerking of pain
• Vestibular stimulation- movement induced nausea and vomiting
• Pruritus-ondansetron
• Histamine release- broncho constriction
• Dimorphine• More soluble than morphine• Large amount can be in small volume• It is used instead of morphine when injections
are necessary• Twice as potent as morphine in iv
Alternative strong opioids
• buprenorphine• fentanyl• hydromorphone• methadone• Oxycodone these are used when patients are intolerant
to morphine
Indication of methadone-• Severe intolerable side effects with morphine
at any dose• Severe pain despite increasingly high doses• Neuropathic pain not responding to typical
regimen of NSAIDs, morphine, TCA and valproate
• Renal failure
• Stop morphine abruptly
• 1/10 dose of 24h oral morphine up to maximum 30 mg
• Allow the patient to take the dose in q3h p.r.n
• On day6 amount of methadone taken over previous 2 days is converted into regular q12h dose
• If p.r.n dose is still neededincrease the dose of methadone by 1/3-1/2 every 4-6 days
• 2nd scheme• Stop morphine abruptly
• 5-10mg methadone q4h and q1h p.r.n
• After12-24h if frequent p.r.n dose is needed
• 10-15mg and q1h p.r.n
• After 72 h convert to q8h and q3h p.r.n
• Increase the dose every 4-5 days
ADJUVANT ANALGESICS
• They are add on drugs supplementing the impact of NSAIDs and opioids
• Its main use is in neuropathic pain
CLASS INDICATIONS
MOA EXAMPLE TYPICAL REGIMEN
ADVERSE EFFECTS
STEROIDS Nerve compression
Reduce peri tomor edema
Prednisolonedexamethasone
15-30mg om8-16 mg o.m
Hyperglycemia,anxiety,steroid psychosis
ANTIDEPRESSANTS
Nerve injury pain
Potentiation of GABA inhibition
Amitriptylineimipramine
25-100 o.n
Antimuscarinis effects,drowsiness,
ANTI EPILEPTIC
Nerve injury pain
Potentiation of GABA inhibition
Valproate
gabapentine
400-1000mg o.n100-300mg tds
drowsiness
NMDA RECEPTOR CHANNEL BLOCKER
Pain poorly responding to analgesics
Nmda receptor block
Methadone
ketamine
10-60mg bd
10-20mg q6h
Drowsiness
dysphoria
Anti spasmodics
Bowel colic Relax smooth muscles
Hyoscine 60-160mg/24h sc
Peripheral anti muscarinic effect
Muscle relaxants
Muscle spasm
Relax somatic muscle
baclofen 10mg tds
bisphosphonates
Metastatic bone pain
Osteoclastic inhibition
Zolendronic acid
4mg every 4-8 week
pyrexia
• ADJUVANT ANALGESICS FOR NEUROPATHIC PAIN
• STEP1-CorticosteroidsT• STEP2-TCA or anti EPILEPTICS
• STEP3-TCA and anti EPILEPTICS
• STEP4-NMDA receptor blocker
• STEP5-Spinal analgesia
ALTERNATIVE ROUTES OF ADMINISRATION
• Dispersible tablets
• Liquids or sprinkling
• Sublingual tablets or suppository or transdermal patch
• Injections
Continuous SC infusions
• Battery driven portable syringe drivers
• Useful in patients with severe nausea and vomiting who cannot swallow drug due to various reason
• Upper chest, upper arm, abdomen, thighs-sites for infusion
• Advantages
• Better control of nausea and vomiting
• Constant analgesia
• Minimum no of injections
• Does not limit mobility
Topical morphine
• 0.1% gel• Pain associated with Cutaneous ulceration
• Oral mucositis
• Vaginal inflammation associated with fistula
• Rectal ulceration
Spinal morphine
• Epidurally or intrathecally
• Much lower dose with greater analgesic effect
• Intractable pain inspite of standard and adjuvant treatment