Procyclidine (Tricyclamol; (±)-Procyclidine) is an anticholinergic agent that functions as a muscarinic receptor antagonist and an N-methyl-D-aspartate (NMDA) antagonist. It is used in studies of Parkinson's disease and related psychiatric disorders, including Soman-induced epilepsy [1][2].

Procyclidine, when administered subcutaneously at dosages between 0.3-6.0 mg/kg in conjunction with physostigmine (PhS), exhibits increased dose-dependent protective effects against soman in rats and guinea pigs, significantly reducing or entirely preventing seizures. The study utilized male Sprague-Dawley rats and Dunkin-Hartley male guinea pigs, observing a substantial enhancement in protection. Specifically, protection levels in rats enhanced by 1.92, 2.24, 3.95, and 5.07 times, and in guinea pigs by 3.00, 3.25, 4.50, and 4.70 times at dosages of 0.3, 1.0, 3.0, and 6.0 mg/kg, respectively. This combination treatment safeguarded neurological brain integrity, effectively preventing severe damage in critical brain areas such as the hippocampus, cortex, amygdala, and thalamus induced by soman exposure.