[The effect of parasympatholytics on the therapeutic effectiveness of the oxime HI-6 against organophosphorus compounds (Soman, substance VX, Fosdrin) in mice].

BACKGROUND: Causal antidotal therapy of acute intoxications with organophosphorus compounds involving administration of the parasympatholytic and cholineesterase reactivator (oxime) has not been resolved so far satisfactorily despite knowledge of the basic mechanism of action of these noxious substances.

METHODS AND RESULTS: In experiments on mice the therapeutic effect of parasympatholytics atropine, benactyzine and biperidene (Akineton) combined with oxime HI-6 on the toxicity of highly toxic organophosphates soman and substance VX and the organophosphorus insecticide phosdrine was compared as regards their influence on the LD50 of these noxious substances during 24-hour survival of experimental animals. Two levels of antidotes were tested. These findings confirm that the LD50 value of untreated intoxication with all three organophosphorus compounds is most increased by oxime HI-6 combined with benactyzine regardless of the antidote dosage.

CONCLUSIONS: Oxime HI-6 is the most effective against highly toxic organophosphates and organophosphorus insecticides when combined with the centrally acting parasympatholytic benactyzine.