scholarly journals The Ability of Oxime Mixtures to Increase the Reactivating and Therapeutic Efficacy of Antidotal Treatment of Cyclosarin Poisoning in Rats and Mice

2012 ◽  
Vol 55 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Jiří Kassa ◽  
Jana Zdarová Karasová ◽  
Růžena Pavlíková ◽  
Filip Caisberger ◽  
Jiří Bajgar

The reactivating and therapeutic efficacy of two combinations of oximes (HI‑6 + trimedoxime and HI‑6 + K203) was compared with the effectiveness of antidotal treatment involving single oxime (HI‑6, trimedoxime, K203) using in vivo methods. In vivo determined percentage of reactivation of cyclosarin‑inhibited blood and tissue acetylcholinesterase in poisoned rats showed that the reactivating efficacy of both combinations of oximes is slightly higher than the reactivating efficacy of the most effective individual oxime in blood, diaphragm as well as in brain. Moreover, both combinations of oximes were found to be slightly more efficacious in the reduction of acute lethal toxic effects in cyclosarin‑poisoned mice than the antidotal treatment involving single oxime. Based on the obtained data, we can conclude that the antidotal treatment involving chosen combinations of oximes brings a beneficial effect for its ability to counteract the acute poisoning with cyclosarin.

2006 ◽  
Vol 25 (5) ◽  
pp. 397-401 ◽  
Author(s):  
Jiri Kassa ◽  
Daniel Jun ◽  
Kamil Kuca

Russian VX ( O-isobutyl- S-(2-diethylaminoethyl)methylphosphonothioate) is the structural analogue of VX agent. It differs from VX agent ( O-ethyl- S-(2-diisopropylaminoethyl) methylphosphonothioate) by two alkyl groups. The potency of currently available oximes (pralidoxime, obidoxime, HI-6) to reactivate Russian VX–inhibited acetylcholinesterase and to eliminate Russian VX–induced acute toxic effects was evaluated using in vivo methods. In vivo determined percentage of reactivation of Russian VX–inhibited blood and brain acetylcholinesterase in poisoned rats shows that HI-6 seems to be the most efficacious reactivator of Russian VX–inhibited acetylcholinesterase among currently used oximes in the peripheral compartment, whereas no difference between reactivating efficacy of all tested oximes was observed in the central compartment. The oxime HI-6 was also found to be the most efficacious oxime in the elimination of acute lethal toxic effects in Russian VX–poisoned mice among all studied oximes. Thus, the oxime HI-6 seems to be the most suitable oxime for the antidotal treatment of acute poisonings with Russian VX as in the case of VX, sarin, cyclosarin, and soman poisonings.


2011 ◽  
Vol 30 (5) ◽  
pp. 562-567 ◽  
Author(s):  
Jiri Kassa ◽  
Jana Zdarova Karasova ◽  
Vendula Sepsova ◽  
Filip Caisberger ◽  
Jiri Bajgar

The ability of 2 combinations of oximes (HI-6 + trimedoxime and HI-6 + K203) to reactivate VX-inhibited acetylcholinesterase and reduce acute toxicity of VX was compared with the reactivating and therapeutic efficacy of antidotal treatment involving a single oxime (HI-6, trimedoxime, K203) in rats and mice. Our results showed that the reactivating efficacy of both combinations of oximes studied in rats is significantly higher than the reactivating efficacy of all individual oximes in diaphragm and roughly corresponds to the most effective individual oxime in blood and brain. Both combinations of oximes were found to be more effective in the reduction of acute lethal toxicity of VX in mice than the antidotal treatment involving the most efficacious individual oxime although the difference is not significant. Based on the obtained data, we can conclude that the antidotal treatment involving the chosen combinations of oximes brings benefit for the reactivation of VX-inhibited acetylcholinesterase in rats and for the antidotal treatment of VX-induced acute poisoning in mice.


2004 ◽  
Vol 47 (2) ◽  
pp. 111-114 ◽  
Author(s):  
Jiří Kassa

1. The influence of the time of administration of antidotal treatment consisting of anticholinergic drug (atropine) and oxime (pralidoxime, obidoxime, HI-6 or trimedoxime) on its effectiveness to eliminate tabun-induced lethal effects was studied in mice. 2. The therapeutic efficacy of antidotal treatment of tabun-induced acute poisoning depends on the time of its administration when obidoxime or the oxime HI-6 was used as an acetylcholinesterase reactivator. 3. Pralidoxime is practically ineffective to eliminate acute toxic effects of tabun regardless of the time of its administration. 4. Our results show that trimedoxime seems to be the most effective to eliminate lethal effects of tabun. In addition, its efficacy does not decrease when it is administered 5 min after tabun poisoning. 5. The findings support the hypothesis that trimedoxime appears to be the most suitable oxime to counteract acute toxicity of tabun because of its ability to eliminate lethal effects of tabun when it is injected 5 min after tabun challenge on the contrary to other oximes tested.


2015 ◽  
Vol 66 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Suzana Žunec ◽  
Božica Radić ◽  
Kamil Kuča ◽  
Kamil Musilek ◽  
Ana Lucić Vrdoljak

Abstract The inability of standard therapy to provide adequate protection against poisoning by organophosphorus compounds (pesticides and nerve agents) motivated us to search for new, more effective oximes. We investigated the pharmacotoxicological properties of six experimental K-oximes (K027, K033, K048, K074, K075, and K203) in vivo. The therapeutic efficacy of K-oximes (at doses of 5 or 25 % of their LD50) combined with atropine was assessed in paraoxon-poisoned mice and compared with conventionally used oximes HI-6 and TMB-4. The bisoxime K074 was the most toxic (LD50=21.4 mg kg-1) to mice, while monoxime K027 was the least toxic (LD50=672.8 mg kg-1). With the exception of K033, all of the tested K-oximes showed better therapeutic efficiency than HI-6 and TMB-4. K027 and K048 stood out by demonstrating low acute toxicities and ensuring protective indices ranging from 60.0 to 100.0 LD50 of paraoxon. Taking into account that these two oximes showed a similar therapeutic efficacy regardless of the applied doses, our results suggest that K027 and K048 could be antidotes for paraoxon intoxication.


2002 ◽  
Vol 45 (2) ◽  
pp. 75-78 ◽  
Author(s):  
Jiří Kassa

1. The influence of oximes (pralidoxime, obidoxime, HI-6) and anticholinergic drugs (atropine, benactyzine, biperiden, scopolamine) on the effectiveness of antidotal treatment to eliminate tabun-induced lethal effects was studied in mice. 2. Obidoxime seems to be the most efficacious oxime for the elimination of tabun-induced lethal effects in mice, although the difference in the efficacy of obidoxime and HI-6 is not significant when they are combined with atropine. 3. Obidoxime and HI-6 when combined with centrally acting anticholinergic drugs (benactyzine, biperiden and scopolamine) seem to be more efficacious in the elimination of toxic effects of the lethal dose of tabun than their combination with atropine. 4. The findings support the hypothesis that the choice of acetylcholinesterase reactivators as well as the anticholinergic drug selection are important for the effectiveness of antidotal mixture in the case of antidotal treatment of tabun-induced acute poisoning.


2004 ◽  
Vol 47 (3) ◽  
pp. 171-175
Author(s):  
Jiří Kassa ◽  
Ivan Samnaliev

1. The influence of two anticholinergic drugs (atropine, trihexyphenidyle) on the effectiveness of antidotal treatment to eliminate soman-induced lethal effects and convulsions was studied in rats. 2. The oxime HI-6 when combined with centrally acting anticholinergic drug trihexyphenidyle seems to be more efficacious in the elimination of acute toxic effects of soman than its combination with atropine. 3. The findings support the hypothesis that the choice of the anticholinergic drug is important for the effectiveness of antidotal mixture in the case of antidotal treatment of soman-induced acute poisoning.


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