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