A-series (“Novichok”) nerve agents: Chemistry, toxicology, detection, and medical countermeasures

Available evidence indicates that A-series (“Novichok”) nerve agents are highly toxic organophosphorus compounds whose primary mechanism of action involves potent inhibition of acetylcholinesterase, resulting in severe cholinergic toxicity and potentially prolonged neurological consequences. Recent analytical advances, including high-resolution mass spectrometry and protein adduct analysis, have substantially improved exposure verification and forensic attribution. Current data support the use of established nerve agent treatment principles, including atropine, oximes, benzodiazepines, and intensive supportive care, although evidence regarding oxime responsiveness and aging kinetics remains limited for several compounds. Existing knowledge of environmental persistence, toxicokinetics, and long-term health effects is constrained by the scarcity of authenticated reference materials and experimental studies. Computational toxicology and machine-learning approaches have provided valuable mechanistic insights but require further experimental validation. Continued multidisciplinary integration of toxicology, analytical chemistry, computational modeling, medicinal chemistry, and public health preparedness will therefore remain essential for improving scientific understanding and response capabilities related to emerging organophosphorus threats.