Pralidoxime
2-PAM
What it isOxime reactivating acetylcholinesterase; organophosphate poisoning.
Why this oneIt reverses nicotinic weakness, including respiratory muscle paralysis, which atropine cannot touch.
What limits itGive it before the enzyme ages; it supplements atropine and is generally not useful in carbamate poisoning.
FDA-approved for
- organophosphate poisoning (~1964)
FDA label
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| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Organophosphate poisoning (IV, with atropine) | Adults | 20–50 mg/kg IV over 15–30 min (max 2000 mg/dose) | Repeat / continuous infusion as needed | Infusion rate ≤200 mg/min |
| Organophosphate poisoning (IM auto-injector) | Adults | 600 mg IM for mild symptoms | Repeat q15min PRN | 1800 mg (3×600 mg) for severe |
| Organophosphate poisoning (IM) | Peds <40 kg | 15 mg/kg IM per injection | Repeat PRN | 45 mg/kg (3-injection course) |
| Anticholinesterase overdose in myasthenia gravis | Adults | 1000–2000 mg IV | Then 250 mg q5min |
Renal Undefined
Hepatic Undefined
Additional doses may be needed q3–8 h if signs of poisoning recur; observe patient 48–72 h
Instructions
- Administer slowly, preferably by IV infusion; use IM or SC if IV not feasible
- Combine with atropinization, decontamination, and supportive care
- Give as early as possible; little benefit if given >36 h after exposure
Cautions
- Reduce dose in renal impairment (excreted renally)
- May cause blurred vision, dizziness, headache, tachycardia, hypertension, muscular weakness when given parenterally
- Signs of atropinization may appear earlier when used with atropine
- Transient elevations in AST/ALT and CPK
Adverse reactions
- Injection-site pain (IM)
- Blurred vision, diplopia, impaired accommodation
- Dizziness, headache, drowsiness
- Nausea
- Tachycardia, increased blood pressure
- Hyperventilation
- Muscular weakness
Pregnancy No animal studies; give only if clearly needed
Lactation Undefined
NO BOXED WARNINGS
Principal riskUseless once the enzyme has aged, and in carbamates
Classes and tags
Clinical profile
Mechanism of action: Pralidoxime ballicule
