Advances in toxicology and medical treatment of chemical warfare nerve agents

Overview

This review summarises how chemical warfare nerve agents cause harm and how exposed patients are managed medically. It is relevant to emergency physicians, intensivists, toxicologists and people involved in disaster and mass-casualty preparedness.

Toxicology

Nerve agents are organophosphorus compounds that inhibit acetylcholinesterase. Acetylcholine then accumulates at nerve endings, producing a cholinergic crisis with muscarinic, nicotinic and central nervous system effects. Clinically this ranges from excessive secretions and bronchoconstriction to muscle weakness, seizures and respiratory failure. The review explains how route of exposure, dose and the progressive, irreversible binding of the agent to the enzyme, known as ageing, affect severity and response to treatment.

Medical management

The priorities are protecting responders and decontaminating patients, then airway management and ventilatory support. Pharmacological treatment rests on three groups of drugs: antimuscarinic agents to counter excessive cholinergic activity, oxime reactivators to restore enzyme function where ageing has not yet occurred, and anticonvulsant therapy to control seizures and limit brain injury. The review also covers intermediate syndromes and possible long-term neurological and psychological effects.

Emerging approaches

Research directions include new reactivators with better central nervous system penetration and broader activity, enzyme-based bioscavengers, improved neuroprotection and pre-exposure prophylaxis for high-risk groups.

Implications for practice

Health systems need preparedness plans, trained staff and access to antidotes. Good outcomes depend on rapid recognition, protection of responders and early supportive and specific treatment.