Pralidoxime
Chemical
Organic compound belonging to methylpyridines
Use
- Tx poisoning due to organophosphates
- Control overdosage by anticholinesterase drugs used to Tx myasthenia gravis
Presentation
Vials 1000mg Pralidoxime chloride
Reconstitute w water
Dose
20-50mg/kg (max 2000mg) in 100ml over 30mins
Second dose 1000-2000mg over 60mins if muscle weakness has not been relieved
Additional doses q12hrly if muscle weakness persists
Route
Slow IV infusion
Onset
16mins (peaks 30mins)
DoA
Half life 3hrs
MoA
Cholinesterase reactivator;
– Organophosphates bind to the esteratic site of Acetylcholinesterase (which inactivates the enzyme)
– Pralidoxime cleaves the phosphate-ester bond formed between the organophosphate & Acetylcholinesterase
– Allows enzyme to recover function
PK
D
No PPB.
Vd 0.6-2.7L/kg
M
Hepatic
E
Excreted in urine, partly unchanged
Adverse Effects
Rapid IV injection – tachycardia, laryngospasm, muscle rigidity, transient neuromuscular blockade