Pralidoxime (2-PAM)
Pralidoxime chloride
Brand names:Protopam, DuoDote (combined with atropine)
An oxime that reactivates acetylcholinesterase inhibited by organophosphate compounds or nerve agents. Pralidoxime addresses the nicotinic effects of cholinergic toxicity (skeletal muscle weakness, paralysis, fasciculations) that atropine does not, making the two medications complementary rather than alternative therapies in nerve agent or organophosphate exposure.
Pharmacology and Actions
Binds to the organophosphate moiety attached to acetylcholinesterase and removes it, regenerating functional enzyme. Most effective when given within 48 hours of exposure, before the organophosphate-enzyme bond ages (becomes irreversible). Aging time varies by agent: VX ages slowly (over 48 hours), sarin ages in hours, soman ages in minutes - making pralidoxime less effective against soman if not given immediately. Addresses nicotinic symptoms (skeletal muscle paralysis, fasciculations, respiratory muscle failure) that atropine does not affect.
Indications
- Nerve agent exposure (sarin, soman, VX, tabun, novichok agents) - given concurrently with atropine
- Organophosphate insecticide poisoning (parathion, malathion, chlorpyrifos)
- Not effective for carbamate poisoning (carbamate-enzyme bond is reversible without oxime; pralidoxime may worsen carbamate toxicity)
Absolute Contraindications
- None in life-threatening nerve agent or organophosphate exposure
- Carbamate-only poisoning (relative contraindication; may worsen)
Precautions and Side Effects
Dizziness, blurred vision, headache, nausea, tachycardia, hypertension (especially with rapid IV administration), muscle weakness paradoxically at high doses, transient ECG changes. Rapid IV administration can cause hypertensive crisis or respiratory arrest - infuse over 15 to 30 minutes when possible. IM route preferred when possible in field settings.
Adult Dosing
Pediatric Dosing
25 to 50 mg/kg IV/IM, max 2 g per dose. Repeat every 1 hour as needed, then every 3 to 8 hours. AtroPen pediatric auto-injectors exist; equivalent pediatric pralidoxime auto-injector limited availability.
Pharmacokinetics
Peak Effect: 5 to 15 minutes IV
Duration: Half-life 1 to 2 hours; clinical effect 4 to 6 hours
Storage and Handling
Room temperature 20 to 25 degrees C; protect from light. DuoDote auto-injectors have specific storage and expiration requirements; check manufacturer guidance and shelf-life extension program (SLEP) certifications for military stocks.
Reconstitution:
Vials of 1 g powder reconstituted with 20 mL sterile water for injection (50 mg/mL concentration). DuoDote auto-injector and Mark I kit do not require reconstitution.
TCCC and TECC Role
Adjunct to atropine in nerve agent and organophosphate exposure response. Standard component of DuoDote auto-injector. Not used in conventional TCCC trauma management but critical for CBRN response capability.
Pralidoxime is the partner to atropine, not a substitute. Atropine reverses the muscarinic effects (secretions, bronchospasm, bradycardia); pralidoxime addresses the nicotinic effects (muscle paralysis, respiratory failure). A nerve agent casualty given atropine alone will dry up and breathe better but may still be paralyzed and unable to ventilate; a casualty given pralidoxime alone may retain muscle function but continue to choke on secretions. The DuoDote combines both for this reason. Timing matters operationally: pralidoxime is most effective given early, before aging of the enzyme-agent bond. For soman, aging is so fast that pralidoxime is of limited value unless administered within minutes.
Administering pralidoxime without atropine. The nicotinic-only reversal does not address the secretions and bronchospasm that are killing the casualty in the short term. Always give atropine first or concurrently. The other common mistake is rapid IV bolus, which can cause hypertensive crisis. The auto-injector IM route avoids this; if IV is required, infuse over 15 to 30 minutes.
This drug profile is provided as educational reference material for trained medical providers. It is not medical advice, not a substitute for formal training, and not a substitute for current published guidelines or medical direction.
Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances are subject to additional handling, accountability, and documentation requirements per DEA and state law. Always verify dosing, indications, contraindications, and route of administration against current published guidelines and your local protocols before administration.
If this content is being viewed during a medical emergency, call 911 immediately and follow the direction of your local emergency dispatch and medical control. Do not use this reference as a substitute for emergency medical services.
Drug information evolves. Last reviewed dates and source citations are provided for each entry. Confirm currency against the cited source before clinical use.
Penn Tactical Solutions publishes this reference for educational purposes. PTS does not provide medical direction and does not assume responsibility for clinical decisions made in the field. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Educational reference for trained medical providers. Not medical advice. Not a substitute for formal training, current published guidelines, or medical direction. Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances require additional storage, accountability, and documentation per DEA and state law.
In a medical emergency, call 911. This reference is not a substitute for emergency medical services.
Verify dosing, indications, and contraindications against current published guidelines and your local protocols before administration. Confirm content currency against the source citation. Penn Tactical Solutions does not provide medical direction. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Pralidoxime (2-PAM)
| IV/IO | 1 to 2 g IV infused over 15 to 30 minutes (dilute in 100 mL normal saline). Repeat every 1 hour as needed for persistent symptoms, then every 3 to 8 hours for up to 24 to 48 hours. Severe exposure may require continuous infusion 500 mg/hr. (5 to 15 minutes (reactivation of enzyme)) |
| IM | 600 mg IM via DuoDote auto-injector (combined with 2.1 mg atropine). Mild exposure: 1 DuoDote. Moderate: 2 DuoDotes. Severe: 3 DuoDotes in rapid succession. Mark I kit (legacy) contains separate 600 mg pralidoxime and 2 mg atropine auto-injectors. (10 to 30 minutes) |
| IN | None (None) |
| PO | None (None) |