A comparison of the efficacy of a new asymmetric bispyridinium oxime BI-6 with currently available oximes and H oximes against soman by in vitro and in vivo methods

The reactivating and therapeutic efficacy of a new acetylcholinesterase rea ctivator, designated BI-6(1-/2-hydroxyiminomethylpyridinium/-4-/carbamoylpy ridinium/-2-butene dibromide), against the organophosphate soman was compar ed with oximes at present used (pralidoxime, obidoxime, methoxime) and H ox imes (HI-6, HLo-7) using in vitro and in vivo methods. H oximes HI-6 and HL o-7 seem to be the most efficacious acetylcholinesterase reactivators again st soman according to the evaluation of their reactivating and therapeutic efficacy in vitro as well as in vivo. The new oxime BI-6 is not as effectiv e as the H oximes against soman, nevertheless it is significantly more effe ctive against soman than the currently available oximes, pralidoxime, obido xime and methoxime, which failed to protect rats poisoned with supralethal doses of soman. Our results confirm that the reactivating efficacy of oxime s evaluated by the methods in vitro closely correlates not only with the po tency of oximes in vivo in reactivating soman-inhibited acetylcholinesteras e but also with the ability to protect rats poisoned with supralethal doses of soman, (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.