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Anticholinergic Chemical-Warfare Agents


James M. Madsen

, MD, MPH, U.S. Army Medical Research Institute of Chemical Defense (USAMRICD)

Reviewed/Revised Jan 2023

There are many types of chemical-warfare agents Overview of Chemical-Warfare Agents Chemical weapons are developed by governments for wartime use and include Toxic agents (intended to cause serious injury or death) Incapacitating agents (intended to cause only temporary, non–life-threatening... read more that affect different parts of the body. "Anticholinergic" refers to drugs that block the effects of the chemical acetylcholine (see Anticholinergic: What Does It Mean? Anticholinergic: What Does It Mean? Anticholinergic: What Does It Mean? ). Acetylcholine is a substance that some nerves use to signal to muscles and other nerves (a neurotransmitter). Thus, blocking the effects of acetylcholine blocks the activity of certain nerves. Although anticholinergic drugs are used to treat poisoning by nerve agents Nerve Chemical-Warfare Agents There are many types of chemical-warfare agents that affect different parts of the body. Nerve agents (sometimes incorrectly called "nerve gas") affect how nerves transmit signals to muscles... read more , anticholinergic drugs can themselves be used as incapacitating agents. Incapacitating agents are designed not to cause serious injury or death but rather to disorient military personnel and keep them from carrying out their missions. One such agent is called BZ (chemical warfare agents typically have a one- to three-letter code that is easier to use than their chemical name).

BZ is a solid that can persist in the environment for 3 to 4 weeks. Mass casualties would likely result from inhalation of aerosolized BZ, although the compound can also be dissolved and placed on a surface in the environment from which it can be absorbed through the skin.

Symptoms of Anticholinergic Chemical-Warfare Injuries

People exposed to BZ have dry mouth and skin, dilated pupils (causing blurring of vision), and usually rapid heartbeat. Their body temperature may also become dangerously high (hyperthermia). They may become lethargic and then develop hallucinations in which they see or hear things. The hallucinations are typically concrete and easily describable (for example, voices of people they know, imaginary television programs, sharing of imaginary cigarettes, or odd shapes). Speech may be slurred, and people often pick at their skin or clothes. Stupor and coma may last hours to days, but people gradually recover.

Diagnosis of Anticholinergic Chemical-Warfare Injuries

  • A doctor's evaluation

BZ exposure cannot be detected through laboratory tests. Doctors suspect exposure in people who develop symptoms without having taken a drug that has anticholinergic side effects

Treatment of Anticholinergic Chemical-Warfare Injuries

  • Lowering of elevated body temperature

  • Physostigmine for agitation and hallucinations

People exposed to an anticholinergic agent such as BZ are usually quiet but may become disruptive and may need to be restrained. Doctors must cool people who have an elevated body temperature (see Heatstroke: Treatment Treatment Heatstroke is a life-threatening condition that results in very high body temperature and malfunction of many organ systems, which may be fatal. (See also Overview of Heat Disorders.) Heatstroke... read more ). They give the drug physostigmine to people who are disruptive or who are markedly distressed by the hallucinations.

The views expressed in this article are those of the author and do not reflect the official policy of the Department of Army, Department of Defense, or the U.S. Government.

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