Narcotic Analgesic

Aka: Narcotic Analgesic, Opioid Analgesic, Narcotic, Opioid, Opiate, Opioid Abuse Deterrent Agent, Opioid Metabolism

1. See Also
   1. Analgesic
   2. Pediatric Analgesic
   3. Acute Pain Management
   4. Opioid Prescription in Acute Pain
   5. Opioid Overdose
   6. Opioid Abuse
   7. Chronic Pain Management
   8. Pediatric Analgesics
   9. Chronic Narcotic Guideline
2. Definitions
   1. Opiate
      1. Naturally occurring, derived from opium poppy
      2. Examples: Morphine, Codeine, Heroin
   2. Opioids
      1. Includes Opiates (naturally occurring)
      2. Semi-synthetic Opioids (structurally similar to Opiates)
         1. Examples: Hydrocodone, Oxycodone, Hydromorphone, Oxymorphone
      3. Synthetic Opioids
         1. Examples: Methadone, Buprenorphine, Meperidine, Fentanyl, Tramadol
3. Adverse Effects
   1. See Opioid Adverse Effect
   2. See Opioid Overdose
   3. See Opioid Abuse
   4. See Opioid Withdrawal
4. Pharmacology: Metabolism of Opioids
   1. Common Metabolites
      1. Codeine: Metabolizes to Hydrocodone and Morphine
      2. Heroin: Metabolizes to 6-acetylmorphine (6-MAM) and then to Morphine
      3. Morphine and Hydrocodone: metabolize to Hydromorphone
      4. Hydrocodone: Metabolizes to Dihydrocodeine
      5. Oxycodone: Metabolizes to Oxymorphone
   2. Renal dysfunction
      1. Safe
         1. Fentanyl (consider reduced dose)
         2. Methadone
      2. Caution (risk of metabolite accumulation)
         1. Hydromorphone
         2. Morphine
         3. Oxycodone
      3. Unsafe (avoid)
         1. Codeine
   3. Hepatic dysfunction
      1. Safe
         1. Fentanyl
      2. Caution
         1. Hydromorphone (decrease starting dose by 50%)
         2. Oxycodone (decrease starting dose by 50%)
         3. Morphine (decreased conversion to active metabolite, increased dosing frequency may be needed)
      3. Unsafe (avoid)
         1. Codeine
         2. Methadone
   4. References
      1. Johnson (2007) Opioid Safety in Patients With Renal or Hepatic Dysfunction, Pain Treatment Topics
         1. http://paincommunity.org/blog/wp-content/uploads/Opioids-Renal-Hepatic-Dysfunction.pdf
5. Pharmacology: Mechanism
   1. Opioid binds Neuron membrane receptor
      1. Calcium (2+) channels close (blocks calcium entry into cell)
      2. Potassium (1+) channels open (allows Potassium to leave cell)
      3. Intracellular cAMP also decreases
   2. Cell becomes hyperpolarized
      1. Charge difference increases between intracellular and extracellular fluid
      2. Decreases likelihood of Neuron activation (firing) in response to a given action potential
   3. Sensory Neurons decrease activity
      1. Results in fewer afferent, sensory signals returning to CNS
      2. Pain Sensation is therefore reduced
6. Precautions: General
   1. Informed Consent for Opioid Prescription
      1. See Opioid Prescription in Acute Pain
   2. Pregnancy
      1. Neural Tube Defects if Opioids used in early pregnancy
      2. Newborn Opioid Withdrawal (neonatal abstinence syndrome) if maternal Chronic Opioid use
      3. No evidence of Tramadol safety
      4. Buprenorphine (without Naloxone) or Methadone may be used for pregnant women with Opioid Use Disorder
      5. (2017) Presc Lett 24(11): 64
      6. (2017) Obstet Gynecol 130(2):e81-e94 +PMID:28742676 [PubMed]
      7. Reddy (2017) Obstet Gynecol 130(1):10-28 +PMID:28594753 [PubMed]
7. Precautions: Ineffective Oral Opioids (Not recommended)
   1. Darvocet N-100 (Acetaminophen 650, Propoxyphene 100)
      1. Dose: 1 PO q4-6 hours
      2. Not available in U.S. as of 2007-2010
      3. Not recommended due to low efficacy and toxicity risk
   2. Tylenol #3 (Acetaminophen 300, Codeine 30)
      1. Dose: 1-2 PO q4-6 hours
      2. Avoid due to low efficacy and increased toxicity risk
8. Precautions: Variable metabolism of oral Opioids
   1. Most oral Opioids are metabolized to active form (e.g. Morphine) by Cytochrome P450 2D6 (CYP2D6)
      1. Codeine
      2. Tramadol (Ultram)
      3. Hydrocodone
      4. Oxycodone
   2. Ultrarapid CYP2D6 Metabolizers
      1. Accounts for 10% of caucasians (may be as high as 30% in some races)
      2. Risk of a rapid conversion to toxic levels of active Opioid (e.g., Morphine)
   3. Slow CYP2D6 Metabolizers
      1. Accounts for 10% of caucasians (or 3% of other races)
      2. Renders the oral Opioids less effective in slow metabolizing patients
   4. References
      1. (2012) Presc Lett 19(6): 33
      2. Crews (2012) Clin Pharmacol Ther 91:321-6 [PubMed]
9. Precautions: Iatrogenic Opioid Overdose prevention
   1. Avoid repeat intramuscular Opioid injection
      1. Risk of dose stacking and secondary CNS/Respiratory depression (esp. Dilaudid)
   2. Titrate dosing to pain while exercising caution in the elderly and Opioid naive
      1. See Dilaudid below for specific precautions
      2. Decrease dose to 50% in the elderly, hepatic insufficiency, Renal Insufficiency
   3. Opioid tolerant patients may still experience respiratory depression on typical Opioid doses
   4. Exercise caution when combining CNS Depressants (e.g. Opioids and Benzodiazepines)
   5. Long-acting Opioids for non-cancer Chronic Pain are associated with significantly increased mortality
      1. Ray (2016) JAMA 215(22): 215-23 [PubMed]
   6. References
      1. Beaudoin (2015) Ann Emerg Med 65(4): 4243-31 [PubMed]
10. Preparations: Acute pain IV Opioids (equivalent to Demerol 50 IV)
    1. Morphine 4 mg IV (2 mg IV in elderly)
    2. Fentanyl 50 mcg IV (25 mcg IV in elderly)
       1. Preferred agent in Renal Insufficiency
    3. Hydromorphone (Dilaudid)
       1. Moderate pain: 0.5 mg IV
          1. Start with 0.2 to 0.3 mg IV in the elderly or Opioid naive
          2. May repeat every 15 to 30 minutes up to 3 doses in the emergency department
             1. Spread interval to every 2-3 hours on the hospital ward
       2. Opioid tolerant or severe pain: Start with 1 mg IV
       3. Dilaudid is a high potency Opioid (1 mg is equivalent to up to 10 mg Morphine)
          1. Most iatrogenic Opioid Overdoses have occurred with Hydromorphone (Dilaudid)
11. Preparations: Oral Opioids by strength
    1. Weak Opioids (WHO Step 2)
       1. Vicodin (Hydrocodone 5, Acetaminophen 500)
          1. Dose: 1-2 PO q4-6 hours
          2. Hydrocodone 10 mg equivalent to Codeine 60-80 mg
       2. Vicoprofen (Hydrocodone 7.5, Ibuprofen 200)
          1. Dose: 1-2 PO q4-6 hours
       3. Tramadol (Ultram)
          1. Dose: 50-100 mg PO q4-6 hours
          2. Tramadol 50 mg equivalent to Codeine 60 mg
          3. Higher cost, but less effective than other Opioids
          4. Metabolized by 2D6 and risk of respiratory depression in ultrarapid metabolizers
          5. Inferior to Vicodin for analgesia
             1. Turturro (1998) Ann Emerg Med 32:139-143 [PubMed]
    2. Strong Opioids (WHO Step 3)
       1. Oxycodone
          1. Adults (and over age 12 years) 5-10 mg every 4-6 hours as needed
          2. Child: 0.05 to 0.3 mg/kg/dose (up to 10 mg) every 4-6 hours as needed
       2. Percocet (Acetaminophen 325, Oxycodone 5)
          1. Dose: 1 PO q6 hours (adults)
       3. Hydromorphone (Dilaudid)
          1. Dose: 2 mg PO q4-6 hours
       4. Morphine Sulfate (MSIR, MS Contin)
          1. Fast Release: 15 to 30 mg PO q4 hours
          2. Sustained Release (MS Contin): 30 mg PO q8-12 hours
       5. Fentanyl Lollipop (100 ug, 200 ug, 300 ug, 400 ug)
          1. Dose: 5 to 15 ug/kg (maximum 400 ug)
       6. Methadone (Dolophine)
          1. Dose: 15 to 60 mg PO q6 to 8 hours
12. Preparations: Oral Opioids by duration
    1. Short acting Opioids
       1. Percocet PO every 6 hours
       2. MSIR 10 mg PO every 4 hours
       3. Hydromorphone 4 mg PO every 4 hours
       4. Vicodin PO every 6 hours
       5. Darvocet N-100 PO every 6 hours
    2. Long acting Opioids
       1. Methadone 20 mg PO every 8 hours
       2. Morphine Sulfate
          1. Controlled release (MS Contin) 30 mg PO q12 hours
          2. Sustained release (Oramorph) PO q8-12 hours
          3. Sustained release (Kadian) PO q12-24 hours
          4. Extended release (Avinza) PO q24 hours
       3. Oxycodone (Oxycontin) 20 mg PO every 12 hours
13. Preparations: MME - Morphine Equivalent Opioid Doses (for comparison only - do not use these doses)
    1. Most potent agents (compared with Morphine)
       1. Fentanyl (Sublimaze) 20 mcg per hour IV or transdermal
       2. Hydromorphone (Dilaudid) 1.5 mg IV (7.5 mg orally)
       3. Methadone 2.5 mg IV (5 mg orally)
          1. Conversion ratio to Morphine is variable per dose
          2. See Methadone for conversion ratios
       4. Oxymorphone 10 mg orally
       5. Nalbuphine (Nubain) 10 mg IV
    2. Morphine (comparison)
       1. Morphine 10 mg IV (30 mg orally)
    3. Less potent agents (compared with Morphine)
       1. Oxycodone 20 mg orally
       2. Hydrocodone 30 mg orally
       3. Meperidine (Demerol) 75 mg IV (300 mg orally)
       4. Codeine 120 mg IV (200 mg orally)
       5. Tramadol (900 mg orally)
14. Preparations: Transdermal Opioid
    1. Fentanyl (Duragesic) Patch
       1. Dose: 25 to 100 ug/hour patch q72 hours
       2. Fentanyl 50 ug/hour equivalent Morphine IV 25 mg/day
15. Preparations: Transmucosal Opioid
    1. Precaution
       1. Indicated for breakthrough Cancer Pain in those using >60 mg/day of Morphine or equivalent
    2. Fentanyl
       1. Sublingual tab (Abstral) 100 mcg
       2. Sublingual spray (Subsys) 100 mcg
       3. Nasal spray (Lazanda) 100 mcg
16. Preparations: Rectal Opioids
    1. General
       1. Do not use lubricant to insert (decreased absorption)
    2. Morphine suppository or tablet 10 to 30 mg rectally q4h
    3. MS Contin 30 mg rectally every 12 hours
       1. Available preparations: 15, 30, 60, 100, 200 mg
17. Preparations: By origin (natural Opiates, semi-sythetic and synthetic Opioids)
    1. Naturally occurring Opiates (opium poppy derivatives, subset of Opioids)
       1. Morphine
       2. Codeine
       3. Heroin (Morphine metabolite)
    2. Semi-synthetic Opioids (structurally similar to Opiates)
       1. Hydrocodone
       2. Oxycodone
       3. Hydromorphone
       4. Oxymorphone
    3. Synthetic Opioids
       1. Methadone
       2. Buprenorphine
       3. Meperidine
       4. Fentanyl
       5. Tramadol
18. Preparations: Opioid Abuse deterrents (e.g. Tamper resistant)
    1. Precautions
       1. Abuse deterrents are inconsistent among products
          1. Long-acting Hydrocodone (Zohydro) is not tamper resistant
       2. Abuse deterrents are not shown to reduce abuse
          1. abuse deterrent may simply offset abuse to other substances (e.g. Heroin)
       3. Abuse deterrents increase Opioid costs up to four fold
    2. Agents with abuse deterrents
       1. Opioids with abuse antagonists
          1. Buprenorphine with Naloxone (Suboxone, Zubsolv)
       2. Opioids with tamper resistance (e.g. break into clumps when crushed or thick gel when wet)
          1. Long-Acting Oxycodone (Oxycontin)
          2. Extended Release Hydromorphone (Exalgo)
       3. Implantable Opioids
          1. Buprenorphine implant (Probiphine)
    3. References
       1. (2014) Presc Lett 21(5): 28
19. Preparations: Adjunctive medications
    1. Alternative non-Narcotics
       1. See Chronic Pain Management
       2. Acetaminophen (Tylenol)
       3. NSAIDs
       4. COX-2 Inhibitors
    2. Stool Softeners or Laxatives
       1. See Bowel Regimen in Chronic Narcotic Use
20. Protocol: Switching between Opioids
    1. Option 1: Rapid conversion
       1. Step 1: Discontinue Drug 1
          1. Calculate equi-Analgesic doses
       2. Step 2: Begin the new Drug 2
          1. Start dose at 20-50% of equi-Analgesic dose
          2. Accounts for drug tolerance to discontinued drug
    2. Option 2: Cross titration
       1. Step 1: Initiate new Opioid while still taking old Opioid
          1. Start new Opioid at lowest available dose
          2. Decrease old Opioid by 10-30%
       2. Step 2: Titrate up the new Opioid while tapering off the old Opioid over 3-4 weeks
          1. Increase new Opioid by 10-20% each week
          2. Decrease old Opioid by 10-25% each week
    3. Precautions
       1. Do not use equi-Analgesic dose or conversion charts for dosing Methadone or non-IV Fentanyl
    4. References
       1. (2012) Presc Lett 19(8): 43
21. Dosing: Maximal effective doses in Chronic Pain
    1. Immediate release agents
       1. One to two tablets up to 4 times daily
    2. Sustained release agents
       1. Morphine: 200 mg/day
       2. Oxycodone: 120 mg/day
       3. Fentanyl: 100 mcg/hour
       4. Methadone: 60 mg/day
    3. References
       1. Chou (2009) Journal of Pain [PubMed]
22. Resources: Dosing Calculators (including MME)
    1. PPM Opioid Calculator
       1. http://opioidcalculator.practicalpainmanagement.com/
23. References
    1. Dachs (2003) AAFP Board Review, Seattle
    2. Hipskind and Kamboj (2016) Crit Dec Emerg Med 30(10): 15-23
    3. (2000) Tarascon Pocket Pharmacopoeia
    4. (2000) Med Lett Drugs Ther 42(1085):73-8 [PubMed]