Nerve Agent Pyridostigmine Pretreatment Tablet Set. Service members are initially issued one NAPP when the chemical protective ensemble is expected to be opened for use. They are responsible for carrying the NAPP and safeguarding it against loss. Orders to start taking the NAPP will be issued by the proper authority within the chain of command. Resupply will be provided by combat, combat support, and combat service support units.
Muscles function as a result of nerve impulses and the release of specific chemical substances.
When a nerve impulse reaches the neuromuscular junction, acetylcholine is released, thereby causing the muscle to contract. The enzyme, acetylcholinesterase, stops the action of acetylcholine on the muscle after the muscle has contracted. Pyridostigmine protects acetylcholinesterase against nerve agents, thus preventing the accumulation of excessive acetylcholine when the MARK I is administrated. A true pretreatment would, by itself, provide some protection against chemical agents. Pyridostigmine is an antidote enhancer.