The primary purpose of the atropine sulfate is to break the bond between the nerve agent and the acetylcholine esterase enzyme, allowing the enzyme to resume its function of removing acetylcholine from the receptors on neurons. The auto-injector is designated as the AtroPen by its manufacturer. The atropine sulfate auto-injector is the smaller of the two injectors and is labeled '1' on the plastic clip, indicating that it was the first to be administered when a service member was showing signs of nerve agent poisoning. The Mark I NAAKs have to be protected from freezing as the expanding ice inside the kit damaged the automatic injection system. Each auto-injector is disposable and can be used only once. Three kits were normally carried by military personnel. The autoinjectors are filled with pre-measured nerve agent antidotes with an automatic, spring-loaded needle injection system. The kit was normally only issued when the threat of nerve agent attack was anticipated. The Mark I NAAK consists of four separate components: the atropine sulfate autoinjector, the pralidoxime chloride autoinjector, the plastic clip, and the foam envelop (carrying case). The Mark I Nerve Agent Antidote Kit (NAAK) is a US military issue countermeasure (antidote) for nerve agent 3 Pralidoxime Chloride (2-PAM Chloride).

1 Mark I Nerve Agent Antidote Kit (NAAK).

Atropine antidote