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Download Opioid-induced hyperalgesia and tolerance
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Jay S Grider DO/PhD Division Chief, Pain Medicine and Regional Anesthesia Medical Director, UKHealthCare Pain Services Associate Professor, Department of Anesthesiology University of Kentucky College of Medicine Lexington, KY Disclaimers • Vertos Medical: Educational Trainer Myths and Legends Myths and Legends Myths and Legends Microdosing df • A concept that attempts to maximize therapeutic and functional benefit for the patient by minimizing the total opioid dose – Patient selection – Psychological mindset – Trialing method – Post-implant patient management scheme Stages of Theory Building • Observation- Describing a phenomena and documenting results goal is stimulate discussion and activity • Classification- Researchers simplify and organize the phenomena based upon it’s attributes • Definition-In depth description of the relationship and categorizing the outcomes. – Carlile and Christensen, Harvard Review, 2010 • Criticism- Microdosing as an untried unverified therapeutic approach – Harden RN, Argoff CE, Williams DA, Pain Med 2012 IDD 2012 • IDD has experienced no growth while oral opioid therapy has exploded – Implant morbidity and mortality – Coffey et al Pain Med 2010 – Inconvenience – Granuloma – Deer et al Neuromodulation 2012 – Ramsey, Witt, Grider et al Pain Physician 2008 – Combo therapy (oral + intrathecal) – Patient satisfaction- lack of control – Expense/Reimbursement IDD 2012 IDD efficacy Patient population Patient Selection Patient management IDD 2004 IDD efficacy Patient Selection Trialing Dosing Microdosing Timeline • 1960’s-70’s – William R Martin MD/PHD Microdosing Timeline • 1960’s-80’s – William R Martin MD/PHD • 1990’s – Scott Hamman MD/PhD – Joe Holtman MD/PhD Microdosing Timeline • 1960’s-70’s – William R Martin MD/PHD • 1990’s – Scott Hamman MD/PhD and Joe Holtman MD/PhD • Early 2000’s – William O Witt MD Original Idea • Dr William Witt – Director Emeritus Pain Medicine Program University of Kentucky Original Idea • Dr William Witt – Director Emeritus Pain Medicine Program University of Kentucky Witt Microdosing Protocol • • • • • • • • Opioid-free interval for 6 weeks Behavioral evaluation with testing Functional evaluation with PT pre-during trial Inpatient intrathecal trial Starting dose 25 mcg/day morphine Every 12 hours double dose to VAS less than 4 Observe 24 at efficacious dose Implant at efficacious dose Protocol • • • • • • Trial Day 1 Trial Day 1 Trial Day 2 Trial Day 2 Trial Day 3 6 am 6pm 6am 6pm 6am 25 mcg/day morphine 50 mcg/day morphine 100 mcg/day morphine 200 mcg/day morphine 400 mcg/day morphine Opioid Pharmacology • Dorsal horn effects • Supraspinal effects • Emotional and addiction centers Descending Modulation • Receptors – Opioid • Mu, Kappa, Delta • Laminea 2 • Pre and post synaptic – Arachadonic acid metabolites Central processing Intrathecal Opioid IDD efficacy Patient Selection Trialing Dosing • Yaksh et al Reg Anesth Pain Med 2000 – Over 15 studies all retrospective – Several areas of focus • • • • • • Drug Selection Patient Selection Trialing technique Starting dose Efficacy of therapy Continued management Early 2000’s Opioid-induced Hyperalgesia 1999-Present • Anderson and Burchiel 1999 • • • Kumar et al Surg Neur 2001 – – • 25 patients with best results in deafferentation and mixed pain Initial dose average 1.1 mg/d increased by 6 months to 3.1 mg/d Thimineur et al Pain 2004 – – • Prospective observational (38 received pump) 10.8 mg/d at 3 years Atli et al 2010 • • • 6.5 mg/d starting dose 12.2 mg/d yr 3 Higher oral opioid consumption correlated with a lower likelihood of long term relief with IT opioids Duarte et al 2012 – – – – • Starting at 2.5 mg/day progressing to an average of 12 mg/day 30% of subjects continued oral opioids Created a predictive model for dose escalation 0.8 mg/d starting dose By year 3 between 2.5-3 mg/d Dose escalation leveled off after yr3 – stable through year 6 Deer et al Consensus Conference Neuromodulation 2012 – – Trialing doses Low (our studies but often in the 1-3 mg range) Recommendations - 0.1-0.5 mg/d Recent Low-dose Study • Hamza, Doleys et al Pain Med 2012 * Morphine equivalents Baseline 3 months 3 years VAS average 7.47 ---------------- 4.02 Oral opioid dose 128.9 mg/d* 3.8 mg/d* -------------------- IT dose 1.4 mg/d* ----------------- 1.48 mg/d* • Nomenclature of low vs microdosing is not well established Opioid-Induced Hyperalgesia • Three clinical settings to consider –Maintenance dosing –High dose therapy –Low dose therapy Opponent Process Theory Opioid-induced hyperalgesia Pain tolerance Opioid-induced analgesia Concept by Walter Ling PhD OIH/Tolerance Reversibility • Opioid addicts in detox –At four weeks no reversibility • Pud et al Drug Alcohol Dependence 2006 –At 6 months however reversibility was demonstrated • Compton J Pain Symptom Mgt 1994 • Hay Proceedings Aust Soc Clin Exp Pharm 2003 Opioid-Induced Hyperalgesia • Three clinical settings to consider –Maintenance dosing –High dose therapy –Low dose therapy OIH Low Dose Opioid Systemically • Opioid agonist systemically in mcg concentrations can ->OIH like picture • Opioid antagonist in mcg-pcg range can result in profound analgesia • Hamman et al 2005 • Mediated by the opioid receptor • Clinical significance of this is lies in the opioid taper Low Dose Hyperalgesia Opioid Plasma Concentration Witt Microdosing Protocol • • • • • • • • Opioid-free interval for 6 weeks Behavioral evaluation with testing Functional evaluation with PT pre-during trial Inpatient intrathecal trial Starting dose 25 mcg/day morphine Every 12 hours double dose to VAS less than 4 Observe 24 at efficacious dose Implant at efficacious dose Protocol Outcomes • Pre opioid taper VAS 7.3 • Post opioid taper VAS 7.15 Opioid Plasma Concentration Witt Microdosing Protocol • • • • • • • • Opioid-free interval for 6 weeks Behavioral evaluation with testing Functional evaluation with PT pre-during trial Inpatient intrathecal trial Starting dose 25 mcg/day morphine Every 12 hours double dose to VAS less than 4 Observe 24 at efficacious dose Implant at efficacious dose Functional Assessment • MPI Pre-opioid taper • MPI 6 weeks opioid free • MPI 12 months post implant 60 57 53 Functional Assessment VAS reported by PT/OT during trial At rest Supine to sitting Sitting to standing Gait Lower body dressing Picking up object from floor Overhead reaching Overall VAS at efficacy Initial 7.3 +/- 1.0 7.8 +/- 0.7 7.3 +/- 0.6 7.4 +/- 1.2 7.7 +/- 1.4 7.2 +/- 0.8 7.5 +/- 0.9 n=0 25 mcg/day (n=20) 6.1 +/- 1.0 5.8 +/- 0.8 5.9 +/- 2.4 5.8 +/- 0.1 5.9 +/- 1.8 6.9 +/- 2.2 4.8 +/- 2.8 n=0 50 mcg/day (n=19) 3.2+/- 0.2 4.0 +/- 1.2 4.1 +/- 2.2 3.8 +/-2.5 4.6 +/- 1.7 5.2 +/- 1.9 5.1 +/-2.4 n=0 100 mcg/day (n=17) 2.8 +/- 1.9 3.8 +/-0.6 2.8 +/- 0.8 3.2 +/-0.3 2.9 +/-0.6 3.8 +/- 2.6 1.8 +/- 2.6 n=7 200 mcg/day (n=10) 1.1 +/- 1.2* 1.9 +/- 1.5* 2.5 +/- 1.1* 2.2 +/- 0.9* 1.8 +/- 1.3* 3.8 +/- 2.6* 1.4 +/- 1.2* n=8 2.1 +/- 0.9* Witt Microdosing Protocol • • • • • • • • Opioid-free interval for 6 weeks Behavioral evaluation with testing Functional evaluation with PT pre-during trial Inpatient intrathecal trial Starting dose 25 mcg/day morphine Every 12 hours double dose to VAS less than 4 Observe 24 at efficacious dose Implant at efficacious dose Dose-Response 8 n=20 n=20 n=19 n=17 n=10 n=2 7 6 VAS 5 4 VAS 3 2 1 0 Initial 25 mcg 50 mcg 100 mcg 200 mcg 400 mcg Dose Efficacy 9 8 Number of subjects 7 6 5 Subjects at Efficacy 4 3 2 1 0 25 mcg 50 mcg 100 mcg 200 mcg 400 mcg Post Implant • One week post implant VAS 3.1 +/- 2.4 – Dose 140 mcg/day • 12 month follow up VAS – Dose 335 mcg/day • Grider et al 2010 Pain Physician 3.9 +/- 2.6 Recent Data • 30 months Retrospective – VAS 4.7 +/- 2.4 – 356 mcg/day daily dose • UK IRB # 08-0921- P6H • 12 month Observational Prospective – VAS implant 3-4 range: Dosing 211 mcg/d – VAS 12 months3-4 range: Dosing 256 mcg/d – MPI Severity 57 to 50 – MPI Interference 53 to 48 • UK IRB # 08-0921-P6H Outcomes • • • • • No patients on oral opioids Minimal dose titration No dose-related side effects Excellent patient satisfaction Improved functional status Future Studies • Possible gender effect – Females may benefit from intrathecal opioids more than males • • Holtman and Walla, Anesthesiology 2009 Hamman et al Receptors and Channels, 2004 • Different pain states • Effect of flow rate • Better monitoring of functional improvement using SF-12v2 • Prospective intrathecal vs oral opioids