Could oxime HI-6 really be considered as "broad-spectrum" antidote?

Abstract

The broad-spectrum reactivator is a valuable oxime able to reactivate acetylcholinesterase (AChE) inhibited by nerve agents and pesticides. At present there are many AChE reactivators (oximes) which are suitable candidates as broad-spectrum reactivators and among them is the oxime HI-6, highly enough thought of to have been recommended by many armies for use as a universal antidote. In this study, we wanted to establish whether the designation "broad-spectrum" is a an accurate description or if there are some lacks in reactivation of nerve agents or pesticides. For this purpose, the general in vitro test for the evaluation of AChE reactivators was used. Tabun, sarin, cyclosarin, soman, VX agent, Russian VX were used as nerve agents for testing, and chlorpyrifos, paraoxon, methyl-chlorpyrifos and dichlorvos (DDVP) were used as typical examples of organophoshorus pesticides. The results obtained showed that oxime HI-6 did not reactivate tabun- and DDVP-inhibited AChE, and, in the case of the other pesticides, only a high dose of oxime HI-6 was able to reactivate pesticide-inhibited AChE.