Analgesic

Naloxone

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Naloxone, Narcan, Very Low Dose Naloxone Protocol, Naloxone Slow Titration Protocol, Evzio, Naloxone Auto-Injector

  • See Also
  • Physiology
  1. Pure Opioid antagonist
  2. Action in under 2 minutes
  3. Effect lasts 45 minutes
  • Indication
  • Opioid overdosage
  1. Respiratory depression (esp. Respiratory Rate <9 breaths/min or increased EtCO2)
  2. Sedation
  3. Hypotension
  4. Hypoperfusion
  • Indications
  • Opioid examples reversed by Naloxone
  1. Heroin
  2. Methadone
  3. Pentazocine
  4. Propoxyphene
  • Indications
  • Opioids requiring increased Naloxone dosing
  1. Propoxyphene
  2. Pentazocine
  3. Buprenorphine
  • Pharmacokinetics
  1. Onset: 1-2 minutes
  2. Duration: 1-2 hours
  1. Route:
    1. Reliable: IV, IO, and ET
    2. Erratic absorption: IM and SQ
  2. Single dose
    1. Child
      1. Under 5 years (under 20 kilograms): 0.1 mg/kg
      2. Over 5 years (over 20 kilograms): 2.0 mg
    2. Adult
      1. Dose: 0.4 to 2.0 mg IVP
      2. Start with 0.4 mg if suspecting severe withdrawal
  3. Repeat dosing
    1. May repeat at 2-3 minutes intervals
    2. Maximum total dose: 10 mg (adults)
  4. Infusion (for long acting Narcotic reversal)
    1. Dose: 0.04 to 0.16 mg/kg/h
  5. Indication-based dosing
    1. Respiratory depression: 0.4 mg IV
    2. Cardiac Arrest: 2 mg IV (if possible Overdose induced Cardiac Arrest)
    3. Concern for Opioid Withdrawal (slow titration method)
      1. See below
  • Dosing
  • Home Prescriptions
  1. Indications: Highest risk patients (but any patient on Chronic Opioids is at risk)
    1. Morphine equivalent dose >50 mg/day (e.g. Oxycodone 35 mg/day, Fentanyl 25 mcg patch)
    2. Substance Use Disorder or history of Overdose
    3. Long-acting Opioid use
    4. Transitioning between Opioids
    5. Concurrent use with other CNS Depressants (e.g. Benzodiazepines or Alcohol)
    6. Comorbidities (e.g. Sleep Apnea, COPD, Asthma)
  2. Background
    1. Caregivers or family members could administer the Naloxone in case of Overdose
    2. Risk of withdrawal symptoms
    3. Patients should be brought to medical facility after use of Naloxone, as half-life of Opioid may exceed 60-90 min
    4. Naloxone dose may be repeated in 2-3 minutes if no effect with first dose
    5. Home rescue Naloxone may curb the >40 daily lethal Opioid Overdoses in the U.S.
  3. Auto-Injector
    1. Dose: 0.4 mg IM/SQ delivered by autoinjector
    2. Very expensive (2 injectors for $600, as high as $4100 for Evzio)
    3. Resources: FDA
      1. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm391465.htm
    4. References
      1. Walley (2013) BMJ 346:f174 [PubMed]
  4. Narcan Nasal Spray ($125)
    1. Does not need to be inhaled to be effective
  5. Custom Naloxone Home Rescue Kit (compounded by pharmacy)
    1. Naloxone 0.4 mg/ml vials with 2 syringes, administered IM prn Overdose ($50-100) OR
    2. Naloxone 2 mg/2ml in prefilled syringes with 2 atomizers administered intranasal prn Overdose ($80-125)
  6. Myth busting
    1. Naloxone prescriptions do not increase risky behavior
    2. Most U.S. states allow for Naloxone prescriptions to Caregivers
    3. No harm if improperly administered or given to a patient not on Opioids
  7. References
    1. (2018) Presc Lett 25(6): 33
    2. (2016) Presc Lett 23(1): 2-3
    3. (2016) Presc Lett 23(8)
  • Dosing
  • Very Low Dose Naloxone Protocol (slow titration method)
  1. Indications: Prevent severe Rebound Pain that would occur with complete Opioid reversal
    1. Cancer Pain
    2. Chronic Pain
  2. Prepare a 0.04 mg/ml Naloxone solution
    1. Start with one Naloxone ampule 0.04 mg/ml
    2. Add saline to make total dose of 10 ml
  3. Dosing protocol
    1. Administer 1-2 ml (0.01 to 0.04 mg) or 1.5 mcg/kg IV or IM
    2. Repeat dose every 3-5 minutes as needed
      1. Titrate dose to Respiratory Rate and mental status
  • Precautions
  1. Recurrence of opioid Intoxication
    1. Occurs if Opioid half life is longer than Naloxone
    2. Infusion may be useful with longer acting Opioids
  2. Infants born to addicted mothers
    1. Naloxone may precipitate acute withdrawal or Seizures
  3. Restrain patient Overdose prior to administration
    1. May precipitate withdrawal
  4. Naloxone may act as Sympathomimetic
    1. May theoretically exacerbate myocardial irritability