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Pralidoxime chloride

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Pralidoxime chloride, Protopam chloride, 2-PAMCl

  • See Also
  1. Nerve Agent Exposure
  • Indications
  1. Not indicated for pure carbamate Poisoning
  2. Nerve Agent Exposure or Organophosphate Poisoning Management
    1. Reverse muscle Fasciculations, Muscle Weakness to Flaccid Paralysis and coma (nicotinic effects)
  • Pharmacokinetics
  1. Binds Nerve Agent and breaks agent-enzyme bond
    1. 2-PAMCl cleaves agent-Acetylcholinesterase bond, freeing the Acetylcholinesterase for activity
  2. Less effective after Nerve Agent aging occurs
    1. Soman (GD) ages in 2 minutes
    2. Other Nerve Agents age over 24-48 hours
  • Dosing
  • Emergency Department
  1. Initial IV bolus
    1. Avoid rapid bolus (risk of laryngospasm or Muscle rigidity)
    2. Adult
      1. Dose: 2 g IM or 1 to 2 g IV (in 100 ml saline as infusion) over 10 minutes
      2. May repeat in 30-60 minutes (if Muscle Weakness not improved), then every 6-8 hours as needed
    3. Child
      1. IV: 25 to 50 mg/kg up to 1 to 2 g in 200 ml D5W or NS IV over 30 min OR
      2. IM: 50 mg/kg up to 2 g IM
      3. May repeat in 30-60 minutes (if Muscle Weakness not improved), then every 6-8 hours as needed
  2. Maintenance Protocol 1 (bolus)
    1. Repeat dosing above in 1-2 hours
    2. May re-administer q10-12 hours prn symptoms
  3. Maintenance Protocol 2 (Continuous infusion)
    1. Continuous IV 10-20 mg/kg/hr up to 500 mg per hour
    2. Discontinue at 24 hours
  • Dosing
  • Military (MARK I Kit)
  1. MARK I Kit Autoinjector contains 2-PAMCl 600 mg
  2. Atropine usually administered prior to 2-PAMCl
  • Precautions
  1. Only administer in combination with Atropine
    1. Without Atropine, 2-PAMCl alone may inhibit Acetylcholinesterase
  2. Do NOT administer more than 3 MARK I Autoinjectors
    1. Cardiac Arrest risk
  3. Most effective if given within minutes (to maximum of hours) of exposure
    1. Nerve Agents irreversibly bind Acetylcholinesterase over time ("aging")
    2. May have effect at 24-48 hours
    3. Liberally administer doses even with mild effects (Neurotoxins may have delayed effect)
    4. Treatment may need to be continued longer (esp. fat soluble compounds)
      1. May continue as infusion (e.g. in adults, 500 mg/h IV)
  • Adverse Effects
  1. Hypertension
  2. Headache
  3. Blurred Vision
  4. Nausea and Vomiting
  5. Hydrocarbon pneumonitis if aspirated
  • References
  1. Tagliaferro (2023) Crit Dec Emerg Med 37(1): 21-9