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Pain and its treatment in psychiatric practice (2) (1)

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Pain and its treatment in psychiatric practice (2) (1)

  1. 1. CHRONIC PAIN IN PSYCHIATRIC PRACTICE DEFINITION OF ACUTE AND CHRONIC PAIN, NOCICEPTIVE AND NEUROPATHIC PAIN, PERIPHERAL AND CENTRAL SENSITIZATION, PAIN AND MOOD, PHARMACOLOGY OF PAIN, CHRONIC PAIN SYNDROMES ADONIS SFERA, MD
  2. 2. RIVER OF PAIN Acheron was known as the river of pain, and was one of the five rivers of the Greek underworld.
  3. 3. THE HISTORY OF MEDICINE IS THE HISTORY OF PAIN • Asclepius, the god of medicine attending to a patient in pain
  4. 4. MORPHEUS AND HIS ELIXIR
  5. 5. TWO PARALLEL HISTORIES: ACUTE AND CHRONIC PAIN Acute Pain Chronic Pain Physiological: protective (survival Pathological: non-protective (no benefit) survival benefit) Causes external: obvious Causes internal: obscure Tissue damage: resolution within CNS changes: may not resolve days/weeks Attended by physicians (illness) Attended by clergy (suffering) Symptom of illness Existential: a social phenomenon The demon is outside The demon is within
  6. 6. CHRONIC PAIN: A WAY OF LIFE • Headaches, backaches, pain in amputated limbs, causalgias and neuralgias have always existed, but the sufferers were not always considered “ill”.
  7. 7. “A WAY OF LIFE” IN OUR SOCIETY • Destitution, Poverty, Homelessness affect health, yet are not being addressed by medical science (a way of life).
  8. 8. MEDICALIZATION OF CHRONIC PAIN • In March of 1899 Felix Hoffman discovered Aspirin. • Aspirin was more than a drug – it changed the way of thinking about chronic pain. • Pain and suffering became medicalized (medical model applied).
  9. 9. A CULTURE OF PAIN AND PAINKILLERS • In 2005 more than 10 million Americans were abusing prescription medications – which is more than the combined number of people abusing cocaine, heroin, hallucinogens and inhalants. • Prescription painkiller overdoses killed nearly 15,000 people in the US in 2008 (three times the 4,000 people killed by these drugs in1999). Scott M. Fishman, MD; Responsible opioid prescribing a physician’s guide; Waterford Life Sciences, 2007
  10. 10. A “PERFECT STORM” OF CONTROVERSY *War on pain *War on drugs • Physicians are being enlisted on both fronts: -combating pain -reducing the risk of diversion, abuse and addiction.
  11. 11. PHARMACOVIGILENCE • The science of detecting, understanding and preventing adverse effects or any other drug related problem.
  12. 12. PAIN: DEFINITION • “An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage” (International Association for the Study of Pain (IASP).
  13. 13. PAIN - A LEARNED EXPERIENCE • Each individual “learns” pain through experiences related to injury in early life. To hear about pain is to have doubt; to experience pain is to have certainty. (Elaine Scarry: The Body in Pain)
  14. 14. PAIN THAT IS PRONE TO BECOME CHRONIC • Type: post-op, post trauma, post-herpes • Neuropathic component: nerve injury • Disability and compensation • Inadequate analgesia • Prolonged pain before surgery • Repeated surgeries • Radiation or chemotherapy • Psychiatric vulnerabilities
  15. 15. CLASSIFICATION OF CHRONIC PAIN Perpheral Neuropathic Central (nociceptive) (non-nociceptive) Inflammation or Damage or Central mechanical entrapment of disturbance in damage peripheral nerves pain processing Classic examples Classic examples -osteoarthritis -diabetic peripheral Classic examples -rheumatoid arthritis neuropathic pain -fibromyalgia -post-herpetic -IBS neuralgia -headaches -LBP -TMJ disorder -Chronic pelvic pain
  16. 16. ALLODYNIA AND HYPERALGESIA Allodinia = Pain evoked by innocuous stimuli. Hyperalgesia = exaggerated pain produced by mildly painful stimuli.
  17. 17. NOCICEPTION (THE AFFERENTS) -A beta fibers respond only to non-noxious stimuli -A delta and C fibers respond to noxious mechanical, heat, and chemical stimuli. Stephen M. Stahl;Stahl’s Essential Psychopharmacology; Third Edition;Cambridge University Press 2008
  18. 18. NOCICEPTION AND NEUROPATHY 1. Sensory Pathway =information about the location and intensity of the painful stimulus (spinothalamic tract). 2. Emotional Pathway =affective component of the pain experience (spinobulbar tract). Combined data from these pathways = human subjective experience of pain.
  19. 19. INSULAR CORTEX – WHERE PAIN BECOMES SUFFERING
  20. 20. VON ECONOMO NEURONS (VEN): INSULA AND ACC
  21. 21. THE PHYSIOLOGY OF INSULAR CORTEX The insulae are believed to be involved in: • emotion • pain • empathy • perception, • self-awareness, • cognitive functioning, • interpersonal experience.
  22. 22. EMPATHY IS PAIN … SORT OF VEN in Insula and Anterior Cingulate Cortex (ACC) are activated when subjects evaluate painful stimuli and when empathizing with others who experience physical pain. The Neural Basis of Empathy;Annual Review of Neuroscience,Vol. 35: 1-23 (Volume publication date July 2012);DOI: 10.1146/annurev- neuro-062111-150536
  23. 23. VON ECONOMO NEURON DISCOVERED IN THE INSULA OF MACAQUE MONKEYS • Published on June 4, 2012: A scientist from the Max Planck Institute discovered that von Economo neuron (VEN) is also found in the insula of macaque monkeys
  24. 24. PERIPHERAL SENSITIZATION (PRIMARY HYPERALGESIA) SENSITIZING SOUP • Hydrogen ions • Noradrenaline • Bradykinin • Histamine • Potassium ions • Prostaglandins • Purines • Cytokines • Serotonin • Nerve growth factor • neuropeptides
  25. 25. PERIPHERAL SENSITIZATION LEADS TO CENTRAL SENSITIZATION
  26. 26. CENTRAL SENSITIZATION (SECONDARY HYPERALGESIA)
  27. 27. PAIN BEGETS MORE PAIN (OVERACTIVE ASCENDING PATHWAYS) Long term potentiation (LTP) is perpetuated by pain and leads to strengthened synapses. These stronger synapses are able to: recruit subliminal inputs.
  28. 28. CAUSES OF SENSITIZATION? When a nerve is severed, the distal portion degenerates and dies. The proximal portion sprouts trying to reach the previous target tissue. The sprouts lack guidance and form tangeled neuromas. Neuromas generate ectopic activity and heightened sensitivity to mechanical, thermal and chemical stimuli. Stephen M. Stahl;Stahl’s Essential Psychopharmacology; Third Edition;Cambridge University Press 2008
  29. 29. EPHAPTIC CROSS-TALK Disruption to myelination may also allow cross-talk between neurons(ephaptic cross- talk). The electrical activity in an A beta fiber neuroma can electrically stimulate activity in a C fiber. Repetitive firing of one neuron can stimulate activity in the neighboring neurons(hyperalgesia and allodynia). Stephen M. Stahl;Stahl’s Essential Psychopharmacology; Third Edition;Cambridge University Press 2008
  30. 30. FUNCTIONAL SOMATIC SYNDROMES (FSS) • Fibromyalgia • Irritable bowel syndrome • Chronic Fatigue Syndrom • Temporomandibular Joint Disorder • Interstitial cystitis Patients with one FSS often suffer from one or more other FSS as well as psychiatric comorbidity.
  31. 31. THE COMPLEX RELATIONSHIP BETWEEN PAIN AND DEPRESSION • The overlap between pain and depression ranges from 30% - 60% • Depression may lower pain threshold (depressed people fell more pain) • Pain may precipitate depression • Patients with chronic pain are at higher risk of developing depression • Pain and depression may be considered integrated. Gallagher RM, Verma S. Semin; Clin Neuropsychiatry 1999; 4 :203-220;Von Korff M, Simon G; Br J Psychiatry.1996;168 (sup 30):101-103
  32. 32. PAIN PATIENTS IN PSYCHIATRIC PRACTICE Psychiatrist: Somatization d/o Rheumatologist: fibromyalgia Neurologist: chronic fatigue syndrome/myalgic encephalomyelitis Patient: “multiple chemical sensitivities”
  33. 33. WAR ON PAIN (FRONTS)
  34. 34. SNRI DRUGS APPROVED FOR CHRONIC PAIN Duloxetine Milnacipran 60 mg once daily; higher doses increase SEs 30-200 mg/day in 2 doses without increasing efficacy in pain disorders Approved for multiple neuropathic pain Approved for fibromyalgia disorders SEs include nausea, dry mouth; can cause SEs: nausea, constipation, sweating, urologic urinary retention, rare activation of suicidality, complaints, urinary hesitancy, dose-dependent increase in blood pressure; can cause rare activation rare hepatotoxicity of suicidality Metabolized by CYP 450 2D6 Few known adverse pharmacokinetic drug interactions Not for use with Thioridazine, MAOIs, or Not for use with MAOIs, or patients with uncontrolled patients with uncontrolled narrow angle narrow angle glaucoma or hepatic impairment glaucoma or hepatic impairment
  35. 35. OTHER SNRI DRUGS Venlafaxine Desvenlafaxine 75-225 mg once daily 50 mg once daily Clinical efficacy in reducing chronic pain Clinical efficacy in reducing chronic pain SEs include headaches, insomnia, nausea, SEs include insomnia, nausea, constipation, sweating, dose dependent increase in BP, rare sweating, increase in BP, rare activation of activation of suicidality suicidality. Use with caution in patients with cardiac Use with caution in patients with cardiac impairment impairment Not for use with MAOIs or in patients with Not for use with MAOIs or in patients with uncontrolled narrow-angle glaucoma uncontrolled narrow-angle glaucoma
  36. 36. ALPHA 2 DELTA LIGANDS Pregabalin Gabapentin 150-600 mg/day in 2-3 doses 900-1800 mg/day in 3 doses Approved in multiple neuropathic Approved in postherpetic pain disorders neuralgia Most common SEs: sedation, Most common SEs: sedation, dizziness dizziness, fatigue, ataxia, nystagmus, tremor Enhances slow-wave sleep Enhances slow-wave sleep Renally excreted Renally excreted
  37. 37. ANTICONVULSANTS FOR CHRONIC PAIN Carbamazepine Oxcarbazepine Topiramate Lamotrigine Zonisamide 1200 mg/day; 1200-1400 50-300 mgday 100-300 mg/day 100-600 mg/day start slow mg/day; start slow Approved for Adjunct for FDA approved Clinical efficacy Some clinical trigeminal neuropathic for migraine in neuropathic efficacy in neuralgia; may pain prophylaxis pain neuropathic have efficacy in pain and other migraines neuropathic pain disorders Induces P450 Less Induction of May have Efficacy can enzymes, may P450 enzymes efficacy in other wane after lower the levels neuropathic several weeks of of other drugs pain disorders. use
  38. 38. TRICYCLICS FOR CHRONIC PAIN Amytriptiline Cyclobenzaprine 25-50 mg once daily 15 mg/day in 3 doses Used for multiple pain disorders 15-30 mg/day in one dose (ER) SEs include sedation, weight gain, Muscle relaxant anticholinergic effects, dizziness, hypotension Metabolized to nortriptyline by CYP 450 1A2 Not recommended for long term use Significant drug-drug interactions SEs: sedation, dry mouth, fatigue headache Use with caution in patients with renal or Use with caution in patients with urinary hepatic impairment retention, angle-closure glaucoma, hepatic impairment Can have cardiovascular effects Can have cardiovascular effects Multiple contraindications Do not use with MAOIs
  39. 39. ON THE OPIOID BORDER: PROPOXYPHENE AND TRAMADOL
  40. 40. OTHER PAIN AGENTS NSAIDs Acetaminophen Baclophen Better for acute pain Less effect on bleeding Muscle relaxant and or for chronic and renal function antispastic inflammatory pain compared to NSAIDs Warning for GI Can cause Used for trigeminal bleeding with SSRIs hepatotoxicity at high neuralgia and some doses other neuropathic pain conditions Combination with Many psychotropics Use with caution in lithium may cause are metabolized by patients with renal lithium toxicity the same liver enzymes impairment
  41. 41. OPIOIDS • Effective for osteoarthritis, rheumatoid arthritis, musculoskeletal pain, postherpetic neuralgia, phantom limb pain, diabetic neuropathy, and chronic low back pain. • No studies of effectiveness beyond 8 weeks • Not effective for fibromyalgia • Risks (dependence, tolerance, pain worsening, reduced effects of SSRIs) Ballantyne JC, Shin NS; Clin J Pain 2008;24:469-78; Clauw. Am J Med 2009;(Suppl 12):S 3-13
  42. 42. OPIOIDS FOR CHRONIC PAIN: THE TWO FACES OF JANUS • Opioids may elicit paradoxical “pain” in both animals and humans. • In humans hyperalgesia is noted in areas of the body different from the site of the original pain complaint. • Methadone maintenance patients are hyperalgesic. • The mechanisms of opioid induced hyperalgesia are unknown Frank Porreca, PHD, University of Arizona, Tucson, Arizona
  43. 43. NONPHARMACOLOGICAL TREATMENTS FOR CHRONIC PAIN • Cognitive behavioral therapy -May work best if targeted to a specific outcome -Adherence may be an issue • Hypnosis, relaxation, guided imagery -May reduce pain, distress • Education -Should be combined with other treatment approaches -Education groups can be useful, but adherence may be low • Aerobic exercise
  44. 44. EVIDENCE BASED TREATMENT OF CHRONIC PAIN SYNDROMES WITH HIGH PSYCHIATRIC CO-MORBIDITY 1. Neuropathic Pain 2. Fibromyalgia 3. Chronic Back Pain 4. Osteoarthritis
  45. 45. NEUROPATHIC PAIN • Diabetic neuropathy - 16% of persons with diabetes. • Postherpetic neuralgia - up to 25% develop neuropathic pain following an episode of shingles. • Spinal stenosis – 3% develop neuropathic pain • Lumbar disc herniation - 4% develop neuropathic low back pain
  46. 46. FIRST LINE DRUGS FOR NEUROPATHIC PAIN • Gabapentin 900-3600 mg/day (Post-herpetic neuralgia) • Pregabalin 75-600 mg/day (Diabetic Neuropathy, Post- herpetic neuralgia) • Duloxetine 60 mg daily (Diabetic neuropathy) • Topical Agents: Lidoderm up to 3 patches/day (Post-herpetic neuralgia) Schatzberg A, Nemeroff C; Textbook of Psychopharmacology; The American Psychiatric Publishing, 2009
  47. 47. DIAGNOSTIC CRITERIA FOR FIBROMYALGIA American College of Rheumatology: 1. Generalized pain that is both widespread (on both the right and the left side of the body, upper and lower halves, and axial as well as proximal arms and legs) and chronic (lasting more than 3 months). 2. Multiple tender points on physical examination (located in the front and back of the neck, upper chest and back areas, iliosacral and posterior gluteal areas, elbows and knees). Schatzberg A, Nemeroff C; Textbook of Psychopharmacology; The American Psychiatric Publishing, 2009
  48. 48. FIBROMYALGIA AND ACCELERATED BRAIN GRAY MATTER LOSS Less gray matter density in fibromyalgia patients vs. controls : -left parahippocampal gyrus (PHG), -left and right mid/posterior cingulate gyrus (CG) -left insular cortex (IC), and -medial frontal cortex Anil Kuchinand, P.Schweinhardt, DA Seminowitz et al.; Accelerated brain Gray Mattewr Tissue Loss in Fibromyalgia Patients: Premature Aging of the Brain, Society of Neuroscience 2007
  49. 49. FIBROMYALGIA - PHARMACOLOGIC AND NON- PHARMACOLOGIC TREATMENTS First line: • SNRIs (Duloxetine, Milnacipran) • Alpha2 Delta ligands (Pregabalin, Gabapentin) • Aerobic Exercise • CBT • Education Second line: • TCAs • Cyclobenzaprine (chemical structure related to TCAs) • Tramadol Schatzberg A, Nemeroff C; Textbook of Psychopharmacology; The American Psychiatric Publishing, 2009
  50. 50. LOW BACK PAIN • The most commonly prescribed medications for low back pain are: • NSAIDs, • Muscle relaxants, • Opioid analgesics. • Benzodiazepines, systemic corticosteroids, antidepressants and anticonvulsants are also prescribed. • Schatzberg A, Nemeroff C; Textbook of Psychopharmacology; The American Psychiatric Publishing, 2009
  51. 51. LOW BACK PAIN GENE? A UK study, published in the Annals of Rheumatic Diseases (Sep. 24, 2012): PARK2 gene was linked to age-related degeneration of the intervertebral discs in the spine, a common cause of lower back pain.
  52. 52. LIFT WITH YOUR KNEES NOT YOUR BACK
  53. 53. OSTEOARTHRITIS • Osteophyte formation • Focus of treatment: reduction of pain, preservation of function. • Acetaminophen • NSAID • Aerobic exercise • Opioids • Not enough evidence for chondroitin, glucosamine and intra-articular hyaluronic acid. • Antidepressants not studied for pain in osteoarthritis, but Katon 2007 looked at the co-morbidity of osteoarthritis with depression (antidepressants helpful) . Schatzberg A, Nemeroff C; Textbook of Psychopharmacology; The American Psychiatric Publishing, 2009
  54. 54. THANK YOU – LET’S STOP HERE

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