Pralidoxime chloride

How it works

It cleaves the bond between the organophosphate and acetylcholinesterase, regenerating active enzyme so that accumulated acetylcholine can be hydrolysed, provided the enzyme has not yet aged.

Prescribing in practice

• Give it as an adjunct to atropine and as early as possible, since it does not replace atropine and loses effect once enzyme ageing has occurred.
• It primarily relieves nicotinic features such as muscle weakness and respiratory muscle paralysis that atropine alone does not address.
• Administer by slow intravenous infusion under specialist or poisons-centre guidance.

Monitoring

Monitor respiratory and neuromuscular status, signs of adequate atropinisation and cholinesterase levels where measurable.

Counselling the patient

• Clarify for the team that this oxime targets the muscle weakness of organophosphate poisoning and complements atropine.
• Emphasise the importance of early administration after exposure.
• Remind staff that supportive care and decontamination remain essential.

Evidence & guidelines

The combination of pralidoxime and atropine is the recognised treatment for organophosphate and nerve-agent toxicity, supported by its SPC and UK poisons information.