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Opioid Selection for Acute and Chronic Pain Control. J K Lilly MD MS Appalachian Pain Therapy Institute Charleston, WV. Objectives. Identify the difference between acute and chronic pain treatment in opioid- naive verses opioid-tolerant patients.
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Opioid Selection for Acute and Chronic Pain Control J K Lilly MD MS Appalachian Pain Therapy Institute Charleston, WV
Objectives • Identify the difference between acute and chronic pain treatment in opioid- naive verses opioid-tolerant patients. • Identify medications appropriate for treatment of each type of pain. • Know the EquianalgesicDoses of IV Morphine, Dilaudid and Fentanyl & convert to oral doses (enterohepatic=1.3). • Know about Iatrogenic Abstinence Syndrome • Realistically apply the Visual Analog Pain Score to evaluating response to opioids. • Differentiate Addiction Disorder from Chronic Pain and Chronic Pain Behavior
Equianalgesic DosingWeak Opioids and Mixed AgonistsDrug PO IM & ½ Life
Equianalgesic Dosing • Consider the example of switching from Methadone 10 tid to Oxycodone-SR • First, determine the Morphine equivalent dose to current drug, • Then, estimate dose of new drug from the Morphine equianalgesic dose i.e. Methadone → Morphine → Oxycodone 30 mg/d x 8 = 240 mg/d x .66=160mg/day
Equianalgesic Dosing • Convert from Fentanyl 50 mcg/hr patch plus Percocet 10/650 up to tid for recurrent pain plus IV Demerol 25 mg up to once per shift for “bad” pain to IV Morphine infusion dose (real example) Fent 50 x24hr=1200 mcg/day x100= 120mg MS; Oxycod 30 x1.3= ~ 40mg MS; Demerol 75 = 75x.1= ~8-10mg MS => 120+~40+~10= ~180mgMS equivalentdose/day or IV-infusion hourly dose of 6.6 mg/hr
Acute Pain Control Plan • Acute Pain: physical discomfort, short duration (hours to weeks), usually severe, usually associated with disease, birthing process or injury • Opioid-Naïve(narcotic celibacy) • Opioid-Tolerant (taking the equivalent of >25 mg/ day of Oxycodone or equivalent dose of any sustained release opioid preparation) • Visual Analog Pain Score (0-10) only advisory!
Chronic Pain Control Plan • Pain lasting longer than six months • Persists disproportionately beyond the initial cause • May not respond in the same way as acute pain to techniques and medications • Cause may not be resolvable! • May require combined treatment modalities • Long Term Opioid Therapy (LTOT) may be the final therapeutic (last/ best) alternative • Chronic Pain Syndrome and its attendant behavior ARE NOT equivalent to Addiction Disorder
Opioid -Naive With PCA (preferred) • Continuous (controversial)- MS 2mg/hr or second line drug in equianalgesic dose (0.2 mg/ hr HM, 20 mcg/ hr Fentanyl) • Demand Bolus - MS 1 mg or equianalgesic dose • Lockout – 10-15 minutes • Rescue– RN administered intermittent rescue ~ twice the dose of PCA bolus q 1 hr prn until reviewed • Review & adjust orders q 12 hrs • Continuous Oximetry
Opioid -Naive Without PCA (but IV) • First Line: Morphine 2mg IV q 5 min prn ‘til comfortable or AE • Second Line: • Hydromorphone 0.2 mg IV q 5 min prn or Fentanyl 20 mcg IV q 5 min prn, (1st if creatanine >2.5) Meperidine not recommended!! • Review orders q 12 hrs • Continuous Oximetry • Convert to Oral ASAP • Avoid 3rd & 4th Line Agents
Opioid Tolerant (taking opioid equivalent to >25 mg Oxycodone/ 24 hrs ) With PCA (preferred) Continuous Infusion = PCA Background – baseline 24 hr opioid dose X .3 per day, (ie. MS Contin 60mg q12h = 120 x .3 = 40mg/24hrs, or 2.5mg/ hr infusion – round-up to 3mg/ hr) PCA Demand- 50-100% of hourly rate, Lockout – q10-15 min Review adjust at least q 12h, titrate systematically Continuous Oximetry
Opioid Tolerant(taking opioid equivalent to >25 mg Oxycodone/ 24 hrs ) Without PCA 10-20% of 24 hr dose q 1-3 hrs prn “basal dose” RN administered IV “Rescue Doses” @ 2x the “basal dose” Continuous Oximetry Adjust doses q 12h
Pain Taxonomy • Acute Pain- tissue injury, distention or inflammation • Episodic Pain- related to activity recurrent, breakthrough, incident • Chronic Pain- constant and unremitting waxes & wanes but seldom subsides
Episodic Pain • Short acting opioids indicated • Oral route preferred • Usually treated Schedule III (+APAP or IB) • Exertion/ Activity related
Constant Pain • Sustained Response (SR) oral agents indicated • Consider Immediate Response (IR) agents for rescue doses – start at ~10% of 24 hr dose of long acting agent q4-8 hrs prn • SR formulations are designed for q 12 hr dosing but mean effective dose may be shorter duration (q 8-10 hr) • Use coanalagesics and anticipate adverse effects • Addiction risk is 3% or less (large studies)
Analgesic Selection • Mu (m) Opioid Receptor Agonists – most familiar to clinicians as to effects and side-effects; best for initiating opioid therapy for moderate to severe pain (VAPS 5-10/10). • Morphine, Hydromorphone, Oxycodone, Hydrocodone, Fentanyl, Codeine, Hydrocodeine, Levorphanol, Methadone, Meperidine. .
Analgesic Selection • Agonist/ Antagonists & Partial Agonists – Primarily activate the Kappa (k) receptor and antagonize or partially occupy the Mu receptor (m antagonists), analgesic ceiling effect, risk iatrogenic abstinence syndrome when given with m agonist tolerant patients, watch out in ER! no proven advantage in avoiding abuse. • Pentazocine, Butorphanol, Nalbuphine and the “partial agonists” Buprenorphine and Dezocine (VAPS 4-7/10)
3rd & 4th Line Analgesic Agents • Limited Proven Analgesic Efficacy • Adverse Effects • Drug-to-Drug Interaction • Toxic Metabolites • Organ-limited Elimination
3rd & 4th Line Analgesic Agents • Propoxyphene equianalgesic to Extra Strength Tylenol in blind studies (VAPS 1-3/10 = mild) norpropoxyphene-cardio & neurotoxic • Tramadol weak m agonist but primarily active on spinal adrenergic receptors similar to tricyclics (VAPS 4-5/10 = moderate) • Meperidine short acting (450-90 mins), metabolites accumulate within 48 hrs, side-effects common normeperidine- cardio & neurotoxic • Codiene effective pain relief but many side-effects at analgesic doses • Hydrocodiene isn’t routinely monitored on UDS • NSAIDs, APAP and AEDs, TCAD are “co-analgesics”
Dosing for Relief • Around-The-Clock (ATC) dosing is associated with more consistent relief • PRN-dosing is associated with more unpredictability and side-effects • Optimal analgesic dosing varies widely among patients; review regularly; titrate systematically • Anticipate side effects; most subside with time • For some, NO dose of opioid will sufficiently relieve ALL of their pain...aim for TOLERABLE pain levels (VPA3-4/10), improved functionality and controlled side effect • Transition quickly from IV to PO (enterohepatic)
Opioids and Addiction Physical Dependence • Physiologic occurrence usually within 3 days of initiating therapy; • Pharmacological property characterized by withdrawal syndrome after abrupt discontinuation; • Abstinence symptoms usually lacking or attenuated with “wean to discontinue” orders • NOT synonymous with tolerance or addiction!
Opioids and Addiction Tolerance • Spectrum of acquired physiologic responses to therapy • Pharmacological property of the class drug; With chronic use, larger dose may be needed for same effect • Countered with drug rotations, furloughs, tolerance inhibitors, prescriptive boundaries • NOT synonymous with physical dependence or addiction!
Opioids and Addiction Pseudo-addiction • Usually attributable to provider practice pattern, ergo iatrogenic • Unrealistic expectation by prescriber • Misconceived safety concern by providers • Patient motivation: ”relief, not rush” • NOT synonymous with physical dependence, tolerance or addiction!
Opioids and Addiction Addiction • Psychological and physiologic state (<3 & >0.3% of chronic pain suffers) characterized by obsessive pursuit of access to medication- regardless of consequences, for psychologicaleffects • Not a pharmacological property of a given drug • NOT synonymous with tolerance or physical dependence!
Plan if Addiction is Recognized -Be Humane -Intervene and Wean to withdrawal -Evaluation, treatment and extended recovery care by addiction professionals is optimal -Know community and regional resources for treatment & extended recovery care when initiating LTOT -Prescribing opioids to treat addiction (Methadone Clinics) is advisable only for specially certified addiction medicine and psychiatry physicians -Buprenorphine Addiction Treatment (Subtex) requires additional training and additional DEA certification…too new to assess.
Opioid TherapyCurrent Clinical Guidelines • Pain relief is defined as a primary care (PCP) function • Remain reasonable, rational, responsible and available • Examine thoroughly and review regularly • Utilize LTOT Informed Consent to TreatandOpiate AccessAgreement • Document & define providers & pharmacy • Require patient to notify all providers of Opiate AccessAgreement participation • Monitorcompliance (pill counts, UDS, etc.) andresponse to therapy (functional assessments, charts, diaries, surveys, etc.), • Review OAA violation consequences regularly • Match the tool to the problem-SR opioid for continual pain, IR for recurrent pain; pick analgesics sensibly
Opioid TherapyCurrent Clinical Guidelines (cont.) • Consult and co-manage appropriately, require formal behavioral assessment periodically • Stipulate that verified non-clinical information may be considered when deciding whether to continue LTOT • Beware of 90 day prescription “Prescription Drug Benefit Requirements” -cost saving scheme that may be technically illegal for opioids; i.e.. unmonitored and unlicensed warehousing of Class II & III medications in homes not supported by law or regulation • Recognize that LTOT may be the therapy oflast resort
Opioid Options on the Near Horizon • Lipid-Based Sustained Release Opioid & Local Anesthetic Vehicles • Vanilloid and Cannabinoid Receptor Agonists • New Spinally-infused Drugs • Abuse-resistant Opioid Preparations • Co-analgesic Use of Anti-seizure Drugs • Deep-Brain and Motor Cortex Stimulation
Opioid Selection for Acute and Chronic Pain Control Thanks for you’re your questions!! It’s time to head home.