Chronic pain Management

1. CHRONIC PAIN ----
Management Update
Dr. Md. Hilalul Islam
Asso. Prof. Of Physical Medicine
M A G Osmani Medical College
Sylhet

2. INTRODUCTION
 Pain is an unpleasant sensory & emotional
experience.
 There are no objective biological markers of
pain.
 It is recognized as a complex phenomenon
derived from sensory stimuli & modified by
individual memory, expectations & emotions
 PAIN MANAGEMENT IS AN ESSENTIAL
REHABILITATION

3. DEFINITION
 Chronic pain can be described as persistent
or recurrent pain lasting beyond the usual
course of acute illness or injury or more
than 3 to 6 months & which adversely
affects the individual well-being.

4. CLASSIFICATION
 NOCICEPTIVE------due to ongoing tissue
injury.
 INFLAMMATORY ------due to chronic
inflammation.
 NEUROPATHIC ------resulting from
damage to the brain, spinal cord or
peripheral nerves.
 MIXED.

5. INCIDENCE IN OLDER
PEOPLE
 One in five older Americans (18%) are
taking analgesic medications regularly
 45% of patients who take pain medications
regularly had seen 3 or more doctors for
pain in last 5 years.
 45 to 80% of nursing home residents have
substantial pain that is undertreated.

6. INCIDENCE IN POST-
SURGICAL PATIENTS
 Amputation ------------30-50%
 Breast surgery--------20—30%
 Thoracotomy--------30----40%
 Inguinal hernia repair-----10%
 CABG-----------------30---50%
 Cesarean section-----------10%

7. RISK FACTORS
 Genetic susceptibility
 Preceding pain
 Psychosocial factors
 Age & sex

8. Genetic susceptibility
 Sensitivity to physiological nociceptive & clinical pain
differs considerably between individuals
 Functional genetic polymorphisms of COMT are
associated with altered sensitivity to pain.
 High COMT activity correlates with a risk of
developing TMJ pain.
 Single neucleotide polymorphisms(SNP) in multiple
candidate genes are with the risk of developing
post-injury neuropathic pain
Differential heritable susceptibility both to the
generation & experience of pain as well as to the
response to analgesics is a recognized fact.

9. PRECEDING PAIN
 Previous pain correlates with the development
of chronic neuropathic pain.
 Severe post herpetic neuralgia is often
preceded by severe zoster pain.
 Amputees with severe phantom limb pain had
more often preamputation pain.
 Similar association is noted with subsequent
development of chronic pain after breast
surgery, thoracotomy & inguinal hernia repair.

10. Psychosocial factors
 In chronic pain of non-surgical origin
psychological, social & economic factors play
a major role.
 Theories about the development of chronic
pain have shifted from a biomedical model to
a biopsychosocial one.
 Preoperative anxiety is correlated with
postoperative pain experience.

11. AGE & SEX
 In postherniorrhaphy pain older patient have
a reduced risk of developing chronic pain.
 In contrast, with post herpetic neuralgia
increasing age is a risk factor.
 Findings of several studies show that women
have higher postoperative pain than men.

12. Guidelines for Management
1. Medical history & physical examination
2. Diagnostic, therapeutic & laboratory results
3. Evaluation & consultations
4. Treatment objectives
5. Discussions of risks & benefits
6. Medications & other treatments
7. Instructions
8. Periodic review

13. Pharmacological treatments
 NSAIDs & analgesics
 Opioid analgesics
 Antidepressants
 Anticonvulsants & Antiepileptics
 Oral antiarrythmics
 Topical pain relievers
 Sedatives & tranquilizers
 Muscle relaxants
 Antihypertensives
 NMDA inhibitors

14. NSAIDs & ANALGESICS
 Most common method of chronic pain treatment
but prolonged use increases the possibility of
adverse reactions.
 Each patient responds differently than the next
patient to the same dose.
 Their use should be determined by benefit, cost,
potential side effects & the patients other
medical problems.

15. OPIOID ANALGESICS
 Opioids are morphine like substances that have
been available for centuries to relieve pain.
 There are endogenous opioids called
endorphins,enkephalins & dynorphins
 Opioids are formulated as both short & long
acting.
 Most opioids are agonists but there are some
partial agonists & agonists/ antagonists.

16. Examples of medical opioids
 Hydrocodone
 Codeine
 Dihydrocodeine bitartrate
 Hydromorphone
 Morphine
 Pentazocin
 Buprenorphine

17. OPIOID DILEMMA
 There are several schools of thought about long term use
of opioid medication
 One believes that it is the right of the patient to have
adequate pain relief even if that requires large amount of
opioids for a long period of time.
 Others believe that there is no real benefit from chronic
use of opioids. The major objections to this treatment
have been concern about tolerance, loss of efficacy, side
effects, functional impairment & tolerance.

18. ANTIDEPRESSENTS
 Pain signals go up the spinal cord to reach the
brain but there are some signals coming down
the spinal cord & that can increase or reduce
pain transmission
 By increasing levels of norepinephrine &
serotonin at nerve endings antidepressants
appear to strengthen the system that inhibits
pain transmission

19. Antidepressants commonly
used for chronic pain
 Amitriptyline
 Nortriptyline
 Desipramine
 Imipramine
 Desipramine is considered to have the lowest
side effects profile of the TCAs.
 SSRI are less effective for treating chronic pain.

20. Benefits of Antidepressants in
chronic pain
 Do not produce gastric irritation as NSAIDs
 May help to reduce depression
 May help to relieve anxiety & panic attacks
 May increase the effect of other pain relieving
drugs
 Non-addictive
 Have a record of long term safety

21. Pain states that may respond to
Antidepressants
 Post herpetic neuralgia Fibromyalgia
 Diabetic neuropathy IBS
 Phantom limb pain RA
 Neuroma pain CLBP
 Central pain following stroke
 RSDS
 Migraine & Tension headache
 Chemotheraphy induced peripheral neuropathy

22. Anticonvulsants & Antiepileptics
used in chronic pain
 Carbamazepine
 Valproic acid
 Gabapentine
 Phenytoin
 Clonazepam
 Lamotrigine
 Tiagabine
 Topiramate
 Levetiracetam
 Oxcarbazine

23. Pain states that may respond
to Anticonvulsants
 Trigeminal neuralgia
 Post herpetic neuralgia
 Damage to nerve plexus
 Diabetic neuropathy
 Multiple sclerosis
 Neuroma
 RSDS
 Migraine

24. Oral Antiarrythmic Drugs
 They are approved for the prevention of
disturbance in heart rhythm but just as they
interrupt premature firing of heart fibers, they also
premature firing of damaged nerves.
 Mexiletine & Flecanide are used.
 They reduce pain in diabetic neuropathy, post
stroke pain, RSDS & traumatic nerve injury

25. TOPICAL ANALGESICS
 Used as topical antiinflammatory agents or
counterirritants.
 Topical salicylates----reduce inflammation
 Capsaicin & EMLA cream ------used in OA,
Diabetic neuropathy & post herpetic
neuralgia

26. MUSCLE RELAXANTS
 Carisoprodol
 Cyclobenzaprine
 Methocarbamol
 Chlorzoxazone
 Baclofen
 Dantrolene
 Tizanidine
 Orphenadrine

27. ANTIHYPERTENSIVES
 Clonidine------a centrally acting alpha
agonist have pain relieving properties in
RSDS.

28. NMDA INHIBITORS
 NMDA inhibitors appear to help prevent
sudden acute pain from progressing into
chronic pain. eg.
 Methadone
 Ketamine
 Dextromethorphan

29. RED SIGNALS DUE TO
PAIN MEDICATION
 Sleeping too much
 Decrease in appetite
 Inability to concentrate
 Mood swings (especially irritability)
 Lack of involvement with others
 Lack of attention to appearance &hygiene.

30. Specific recommendations in
Older Peoples
 All older patients with diminished quality of life
as a result of chronic pain are candidates for
pharmacological therapy.
 The least invasive route should be used.
 Fast-onset, short-acting analgesic drugs should
be used for episodic pain.
 Acetaminophen is the drug of choice for mild to
moderate musculoskeletal pain
 NSAIDs should be used with caution.

31. (continued)
 Opioids for episodic pain should be prescribed as
needed rather than around the clock.
 Titration should be based on the pharmacokinetics &
pharmacodynamics of specific drugs in the older person
& the propensity for drug accumulation
 Constipation should be prevented.
 Patients with long- term NSAIDs should be periodically
monitored for GI blood loss, renal insuffifficiency, &
other drug-drug or drug-disease interaction.

32. NON-PHARMACOLOGICAL
MANAGEMENT
 Education programs
 Cognitive behavioral therapy
 Exercise programs
 TENS
 Thermo therapy
 Massage
 Relaxation

33. Specific recommendations for
Older People
 Nonpharmacological interventions can be used alone or
in combination with pharmacological strategies for
chronic pain management.
 Patient education should be provided for all patients
with chronic pain.
 Cognitive-behavioral therapy should be applied as a
structured program that includes components of
education, rationale for therapy, coping skills& relapse
prevention.

34. (continued)
 Exercise should be a part of care of all older
patients with chronic pain.
 Exercise should be tailored to the need &
preferences of the patient in consultation of the
primary clinician.
 A trial of physical or occupational therapy is
appropriate for the rehabilitation of impaired range
of motion, specific muscle weakness or other
physical impairment associated with chronic pain.