1 / 46

PHARMACOLOGY OF CHRONIC PAIN MANAGEMENT

PHARMACOLOGY OF CHRONIC PAIN MANAGEMENT. April 15, 2011 Michael J. Schwartz, M.D. Founder & Director OKLAHOMA PainCare, Inc. CHRONIC PAIN - CNS. PAIN ROADMAP. Noxious stimulus in periphery transduced into electrical activity Bidirectional process with both ascending and descending inputs

adara-pugh
Download Presentation

PHARMACOLOGY OF CHRONIC PAIN MANAGEMENT

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. PHARMACOLOGY OF CHRONIC PAIN MANAGEMENT April 15, 2011 Michael J. Schwartz, M.D. Founder & Director OKLAHOMA PainCare, Inc.

  2. CHRONIC PAIN - CNS

  3. PAIN ROADMAP • Noxious stimulus in periphery transduced into electrical activity • Bidirectional process with both ascending and descending inputs • Normal response is protective and adaptive • Persistent pain → maladaptive • Neuroplastic changes that affect pain perception • Ultimately pain sensations out of proportion

  4. CHRONIC PAIN - CNS

  5. Acute vs Chronic Pain

  6. Pain-Sensing System Malfunction in Chronic Pain Normal Pain • Pain-sensing signals are initiated in response to a stimulus • They elicit a pain-relieving response Chronic Pain • Pain signals are generated for no reason and may be intensified • Pain-relieving mechanisms may be defective or deactivated

  7. Pain-Sensing System Malfunction in Chronic Pain • Sensitization of peripheral nociceptors → ↑magnitude and speed • Hyperalgesia • Activation of low-threshold mechanreceptors • Allodynia • Touch → pain

  8. Central sensitization • Loss of inhibitory effects of myelinated primary afferents • Reorganization of spinal cord connections after deafferentation • Spontaneous activity in deafferented spinal pain transmission neurons • Prolonged excitation or sensitization of spinal pain transmission neurons

  9. CHRONIC PAIN Pain Sensing • Pain signals are generated without physiologic significance

  10. CHRONIC PAIN • Pain signal outlived its use • Becomes faulty wiring • ‘Wind-up’ of the pain signal • Louder and faster • CNS sub-optimal pain perception & processing • No longer a healthy pain response

  11. BASICS • The International Association for the Study of Pain (IASP) defines pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage” • Pain is the most common reason people seek medical attention • Pain is a ubiquitous phenomenon • The same set of circumstances can cause significant pain in one patient, and little or none in another • Pain is both a sensory and an emotional experience

  12. HOUSE of PAIN • Pain is a dirty 4-letter word • HONESTY of patient and physician • Weakness • Suck it up; “buck-up” • Avoid responsibilities • Work, family dynamics, parenting • Worthless; guilt; ‘no way out’

  13. Importance of Chronic Pain • When improperly managed, pain can lead to decreased productivity and diminished quality of life • Estimates show that chronic pain affects approximately 90 million Americans each year • The burden placed on our society in financial terms is tremendous! • Approximately ≥ $100 billion per year including medical expenses, lost wages, and decreased productivity

  14. TYPES OF PAIN • Acute nociceptive • Inflammatory/joint • Hypersensitive response to tissue damage and inflammation • Visceral nociceptive • IBS; IBD; IC; Crohn’s; endometriosis; etc • Neuropathic • Constant alarm without emergency, maladaptive, spontaneous, flunctuating • DPN; vascular neuropathy; TGN; PHN; etc

  15. Pain coaching Life counseling CBT; ACT Pain psychologist Sleep evaluation Rehabilitation Interventional Blocks SCS; IT pump Neurolytic procedures Pharmacology Opioid Non-opioid adjuvants SMRs; AEDs; SNRIs; SSRIs; NSAIDs (non-selective COX-I and selective COX-II; anxiolytics; hypnotics; dopaminergics; etc Medical Management of Chronic Pain

  16. Pharmacologic options • Opioids • Non-opioid adjuvants: • Antidepressants (SNRIs & SSRIs) • Anticonvulsants (AEDs) • NSAIDs, • non-selective COX-I • selective COX-II • Local anesthetics • SMRs • -adrenergic agents • Topical agents

  17. DEFINITIONS Physical dependence: normal adaptation to a drug-class • Abrupt cessation, rapid↓dose, antagonist, etc →withdrawal syndrome Tolerance: drug exposure → ↓effect over time Addiction: primary, chronic, neurobiologic DZ with genetic, psychosocial & environmental influences

  18. DEFINITIONS Addiction behaviors: • Impaired control over drug use • Compulsive use • Continued use despite harm • Craving • ‘Mad, sad or glad’

  19. DEFINITIONS Abuse: • Illegal drug use • Self-administration of meds for non-medical purpose • Altered state of consciousness • ‘Getting high’ • Go to Disney World without leaving the couch

  20. DEFINITIONS Aberrant drug-use behavior: • Outside the boundaries of the agreed upon treatment plan established in the patient-physician relationship Misuse: • Use of medication for medical purpose other than as directed or as indicated, whether willful or unintentional, and whether harm results or not

  21. DEFINITIONS Diversion: • Intentional transfer of a Controlled Dangerous Substance (CDS) medication for illegitimate use • Sell, trade, give, take, etc

  22. HOUSE of PAIN • Pain patients practice to be worse • Pain Brain

  23. Chronic pain circle

  24. GOALS of the pharmacologic management of chronic pain Optimally contain the daily chronic pain Improved quality of life (QOL) • Improved function physically and emotionally Fewest adverse side effects (ASEs) Fewest cognitive side effects (CSEs)

  25. Pharmacologic options • Opioids • Non-opioid adjuvants • Antidepressants (SNRIs & SSRIs) • Anticonvulsants (AEDs) • NSAIDs • Non-selective COX-I • Selective COX-II • Local anesthetics • SMRs • -adrenergic agents • Topical agents

  26. OPIOIDS for daily use Extended-release preferred • Morphine • Oxycodone • Oxymorphine • Hydroxymorphine • Fentanyl • Buprenorphine

  27. Immediate-release short-acting opioids (IRSAOs) AVOIDdaily use of repetitive doses • Increased need for dosage escalation • Increased risk of true addiction • Increased risk of cognitive and motor impairment • APAP combo meds →liver & renal toxicity

  28. Long-acting opioid (LAO) Methadone • Unique characteristics • CAUTION! • For use only by clinicians familiar with its use and risks • A leading cause of inadvertent and accidental overdose and death

  29. Methadone Must monitor: • K⁺, Na⁺⁺, Mg⁺⁺ • EKG • QT interval Dosing: • Q 6hr optimal – strict schedule

  30. OPIOID POLICIES • Federal laws • State laws • Regulatory guidelines • Policy statements

  31. MANAGING CHRONIC PAIN WITH OPIOIDS • Patient selection • One size does not fit all • Risk stratification • Informed consent and opioid management plan • Goals of treatment • Expectations • Risks and alternatives

  32. MANAGING CHRONIC PAIN WITH OPIOIDS • Monitoring patients: • Level of function • Progress towards goals • Presence of adverse events • Compliance • Psychotherapeutic co-interventions • Driving and work safety • Breakthrough pain • Exit strategy

  33. MANAGING CHRONIC PAIN WITH OPIOIDS • Monitoring patients: • 4 As • Analgesia • ADLs - level of function, progress towards goals • Adverse events – ASEs, CSEs • Aberrant medication use - compliance

  34. PATIENT ASSESSMENT FOR OPIOID THERAPY • Chief complaint • Pain history • Pain medication history • Past history • Including psychiatric hx and substance use & abuse hx • Social history • Family history • Including psychiatric hx and substance use & abuse hx

  35. PATIENT ASSESSMENT FOR OPIOID THERAPY • Physical examination • Features relevant to pain and substance use • Additional information: • Urine and/or serum drug test monitoring • Screening for risk of substance use or aberrant medication-use behavior • Outside medical records • Prescription monitoring reports (OBN PMP)

  36. OPIOID RISK ASSESSMENT • Opioid Risk Test (ORT) • Screener and Opioid Assessment for Patient with Pain (SOAPP) • SOAPP-14, SOAPP-24, SOAPP-R (revised) • Current Opioid Misuse Measure (COMM) • Zung, HAM-D, HAM-A, etc • Other non-opioid eg. Epworth

  37. Aberrant Drug-Taking Behaviors Probably more predictive: • Selling scripts • Prescription forgery • Stealing or borrowing meds • Obtaining scripts from nonmedical sources • Concurrent abuse of related illicit meds • Multiple unsanctioned dose escalations • Recurrent script or med losses

  38. Aberrant Drug-Taking Behaviors Probably less predictive: • Aggressive complaining about pain intensity and need for higher doses • Drug hoarding • Requesting specific medications • Obtaining CDS meds from other medical source • Unsanctioned dose escalation 1-2 times • Use of med to tx other symptoms • Reporting psychic effects of meds

  39. Opioid conversions Equianalgesic dose calculations of different opioids • Reduce amount by ≥ 50% • Methadone different animal • Propoxyphene off market • FDA banned in Feb 2011 • Meperidine not for chronic pain management • “Demerol blizzard”

  40. Defects in Opioid Metabolism Genetic screening • Cytochrome 450 (CYP 450) • CYP 2D6; CYP 2C9 • Most common defect CYP 3A4 • Testing not available • Why? • Avoid drug interactions (ADRs) • High-dose opioids • Unusual or expensive regimen

  41. Defects in Opioid Metabolism • Suspect genetic metabolic defect if when opioid blood levels are very high or very low • Screening costly • Insurance says “experimental”

  42. Exit Strategy for discontinuing opioid therapy • Opioid risk-benefit ratio • Intolerable side effects • Opioid rotation failure • Deterioration of QOL • Poor compliance • Aberrant med-use behavior • PPP – mean disagreeable pts

  43. American Academy of Pain Managementhttp://www.aapainmanage.org/ - The American Academy of Pain Management is a non-profit organization that educates clinicians about pain and its management through an integrative interdisciplinary approach. American Academy of Pain Medicinehttp://www.painmed.org/ - The American Academy of Pain Medicine (AAPM) is the medical specialty society representing physicians practicing in the field of Pain Medicine American Chronic Pain Associationhttp://www.theacpa.org/ - To facilitate peer support and education for individuals with chronic pain and their families so that these individuals may live more fully in spite of their pain. American Pain Foundationhttp://www.painfoundation.org/ - NPO site that contains newsletter, downloadable patient resources (MS Word), and discussion boards. American Pain Society (APS)http://www.ampainsoc.org/ - Multidisciplinary, scientific and professional society. Contains announcements of positions, fellowships, grants, etc. American Society for Action on Painhttp://www.druglibrary.org/schaffer/asap/ - Patient organization interested in pain management issues/concerns. American Society for Pain Management Nursinghttp://www.aspmn.org/ - Organization of professional nurses that provide support to pain management. Contains announcements and an e-mail list. American Society of Addiction Medicinehttp://www.asam.org/ - Site dedicated to increasing the quality of addiction treatment. Includes certification, publications, and conference info. American Society of Regional Anesthesia and Pain Medicine http://www.asra.com/ - Member info, web-based CME, and fellowship opportunities are some of the highlights. Drugs4Realhttp://www.drugs4real.com/ - An interactive prevention program that teaches adolescents about the influence of alcohol and drugs and strengthens their commitment to avoid taking these substances. International Association for the Study of Pain (IASP)http://www.iasp-pain.org/ - NPO consisting of health professionals. Access to web-based learning, grants/awards, opportunities, etc. National Pain Foundationhttp://www.painconnection.org/ - A non-profit organization that provides education and support resources for people in chronic pain, their families, and physicians. Pain & Policy Studies Group, University of Wisconsinhttp://www.painpolicy.wisc.edu/ - The Pain & Policies Studies Group website contains a wealth of information about pain relief and public policy, both domestic and international. Pain Medicine Newshttp://www.painedu.org/www.painmedicinenews.com - Pain Medicine News has timely frequently updated content designed to meet the needs of the spectrum of physicians involved in pain medicine. Pain Treatment Topicshttp://www.pain-topics.org/ - With pharmaceutical company support, a noncommercial resource for healthcare professionals, providing clinical news, information, research, and education for a better understanding of evidence-based pain-management practices. Pain.comhttp://www.pain.com/ - Free web-based CME, articles, and pain journals (all free to view). PainACTIONhttp://www.painaction.com/ - An online self-management program for pain patients, featuring individually-customized information, interactive skill-building tools, monthly newsletter and opportunities to share self-management tips. PainLinkhttp://www.edc.org/PainLink/ - Archived website that still contains applicable information. The Mayday Fundhttp://www.painandhealth.org/ - Extensive listing of internet resources relating to pain and pain management. Wisconsin Pain Initiativehttp://www.wisc.edu/wcpi - Grassroots organization of professionals that includes: pain management laws (WI), patient/public/professional education. Chronic Pain Resources

  44. OPIOIDOLOGY • Universal Precautions for Opioid Pain Management • Federation of State Medical Licensure Boards • Guidelines of American Pain Society & American Academy of Pain Medicine • PHARMACOLOGY

  45. Michael J. Schwartz, M.D. • OKLAHOMA PainCare, Inc. • drschwartzopc@coxinet.net • Opinions are like rear-ends – we’ve all got one – “and now I’ve shown you mine”

More Related