The ability of Czech original mixed pharmacological pretreatment, designated PANPAL (pyridostigmine in combination with benactyzine and trihexyphenidyle) to increase the resistance of soman-exposed mice in the case of non-treated or treated poisoning was compared to the currently used pharmacological pretreatment involving pyridostigmine alone. A significant decrease in the LD50 values of soman in the case of non-treated poisoning of mice was observed when the rats were pretreated with PANPAL. On the other hand, the pharmacological pretreatment with pyridostigmine alone was practically ineffective to protect mice against soman-induced acute toxicity. The pharmacological pretreatment with pyrido- stigmine alone was not able to increase the efficacy of perspective antidotal treatment (the oxime HI-6 in combination with atropine), administered to mice one minute following soman poisoning. In contrast, PANPAL significantly increased the therapeutic effectiveness of antidotes studied in soman-poisoned mice. In addition, PANPAL-induced increase in the efficacy of currently used antidotal mixture (obidoxime in combination with atropine and diazepam) was significantly higher than the increase in the effectiveness of antidotes induced by pyridostigmine alone. These findings confirm that PANPAL pretreatment of soman-poisoned mice seems to be much more suitable pharmacological pretreatment against nerve agents than pyridostigmine alone.

Keywords: Soman; Pyridostigmine; PANPAL; HI-6; Atropine; Obidoxime; Diazepam; Rat