Tuesday’s symposium relating to new developments in the management of nerve agent poisoning struck a nerve with toxicologists dedicated to protecting soldiers and civilians from nerve agents used during warfare and terroristic attacks. Nerve agents are made of various organophosphate chemicals that attack the body’s nervous system and inhibit the enzyme acetylcholinesterase. This enzyme inhibition results in build-up of the neurotransmitter acetylcholine, with resulting signs of toxicity—labored breathing, inability to walk or talk, painful muscle spasms, seizures, and at sufficient doses, death.
Professor Allistar Vale of the University of Birmingham and Chief Scientist Paul Rice of the UK Defence Science and Technology Laboratory provided insightful and rather sobering overviews of nerve agent poisoning:
- More than 20 countries have acquired chemical weapons, including nerve agents.
- Terrorists have a track record of acquiring expertise in developing nerve agents, as exampled by the Japanese cult Aum Shinrikyo. In the 1990s, this cult learned how to produce VX and sarin, and within 6 months built a plant capable of producing 2 tons of nerve agent per day.
- One drop of VX on the skin can be lethal and cause death in minutes.
There are multiple nerve agents such as GB (sarin), GD (soman), GA (tabun), VX, and VR, some of which are quick acting and require immediate therapy (G series nerve agents), while others are slow acting (V series) and require prolonged therapy.
Some of the challenges associated with the effective treatment of nerve agent poisoning include the lack of a single antidote for nerve agent poisoning, delayed identification of a specific nerve agent used in an attack, putting medical responders at a disadvantage when treating individuals poisoned with an unnamed nerve agent that may be slow-acting or fast-acting.
Horst Thiermann of the Bundeswehr Institute of Pharmacology and Toxicology in Germany discussed the practical application of lessons learned from nerve agent poisoning to diagnose and treat nerve agent poisoning. Promising developments in treatments were described by Dr. Janice Chambers of University of Mississippi, who described her work developing centrally effective oxime reactivators for organophosphate-inhibited acetylcholinesterase. Managing nerve agent poisoning will require use of combination therapies, development of new antidotes, as well as changes in dosing and treatment regimens.
This blog discusses highlights from the SOT Annual Meeting and ToxExpo Symposium Session “New Developments in the Management of Nerve Agent Poisoning”