ABSTRACTHaving sufficient medical countermeasures (MCMs) available for the treatment of acetylcholinesterase-inhibiting nerve agent poisoned patients following a mass chemical exposure is a challenge for communities. After stockpiles containing auto-injectors are exhausted, communities need to be aware of alternative pharmaceutical options. The Department of Homeland Security Chemical Defense Program convened a federal interagency working group consisting of first responders, clinicians, and experts from the fields of medical toxicology, pharmacology, and emergency management. A literature review of pharmaceutical alternatives for treating nerve agent toxicity was performed. Pharmaceuticals that met the federal Public Health Emergency Medical Countermeasures Enterprise Product Specific Requirements were prioritized. Food and Drug Administration approval for one indication, market availability, and alignment to government procurement strategy were considered. This article summarizes the literature on comparative pharmacokinetics and efficacy against nerve agents (where available) of Food and Drug Administration approved drugs with muscarinic acetylcholine receptor antagonist and gamma-aminobutyric acid receptor agonist effects. This work is intended to serve as a resource of pharmaceutical options that may be available to communities (ie, emergency managers, planners, clinicians, and poison centers) when faced with a mass human exposure to a nerve agent and inadequate supplies of MCMs. (Disaster Med Public Health Preparedness. 2018;page 1 of 8).