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management of suspected FGA exposures differs from the approach used for
traditional nerve agents. All individuals suspected of having been exposed need to
be identified, decontaminated, and observed, with serial determinations of RBC
cholinesterase or plasma cholinesterase as well as heart rate and temperature
monitoring. Meanwhile, epidemiologic clues may lead to the identification of
additional possibly exposed individuals.
A-series agents are difficult to treat once victims have gone into cholinergic
crisis; aggressive treatment with atropine and an oxime is needed along with
scopolamine (initially 1 mg IV in adults; the dose may be scaled down for
children). During the latent period, victims need to be decontaminated thoroughly
as soon as possible, although decontamination may be effective even an hour or
two after exposure. Heart rate, core temperature, and cholinesterase levels in the
blood or plasma (or both) should be monitored. Pyridostigmine bromide (PB) 30
mg orally every 8 hours in adults (lower doses scaled to body weight are
appropriate for children) should be considered; this is normally given as a
pretreatment for nerve-agent exposure and is not given after the onset of
cholinergic crisis. PB is a carbamate anticholinesterase used in anesthesia and in
the treatment of conditions such as myasthenia gravis. At the time of the 1990
Gulf War, the U.S. FDA approved it as a pretreatment to be given before
exposure in situations in which the risk of exposure to the traditional nerve agent
soman (GD) was high. (PB is a pretreatment , or pre-exposure antidotal
enhancement, not prophylaxis ; it helps antidotes to work better, but the antidotes
still have to be given.) Subsequently, the FDA extended that approval for
conditions in which exposure to any nerve agent was likely. PB pretreatment is
not normally a consideration outside military scenarios, but because of the long
latent periods with FGAs, administration of PB during the latent period, when the
outside of the body has technically been exposed but the target organs (the CNS,
skeletal muscles, smooth muscles, and exocrine glands) have not yet been
exposed, could theoretically be of use. If a provider–patient relationship exists,
PB might be considered when given under informed consent. PB will predictably
depress cholinesterase levels, but the drop is only about 30% from the

preadministration values; if cholinesterase levels drop precipitously during the
latent period, or if the heart rate or core temperature decreases by more than 25%
from baseline, the patient should be treated for full-blown cholinergic crisis.