Sarin clinical effects

The attack with sarin on the Tokyo Subway (underground railway) has added considerably to our knowledge of the clinical effects of sarin vapor. The symptoms observed were largely as expected, namely cough, difficulty in breathing and tightness of the chest, bradycardia and eye pain (Masuda et al., 1995 Nozaki et al., 1995 Ohbu et al., 1997) (see Chapter 13). 

The effectiveness of non-lethal doses of agent sarin, a strong inhibitor of both RBC (true) and plasma (pseudo) cholinesterase, was impressive (Fig. 70). In two subjects who were treated with the same dose of sarin, however, the benefit was greater in one (red) than the other (yellow). Differences in RBC cholinesterase inhibition may explain this disparity. In studies b Drs. Sidell and Aghajanian, levels of plasma cholinesterase were sometimes reduced almost to zero by sarin, without producing clinical signs of toxicity (note reversal in upper legend, which has plasma as xx and RBC as yy )-... 

One piece of evidence supporting the efficacy of PAM in sarin toxicity has been the clinical benefit associated with PAM in toxicity due to organophosphorous agrochemicals. However, some experts now doubt whether such a benefit really exists. For example, Peter et al (2006), using meta-analytic techniques, reevaluated the effects of oxime therapy in organophosphate poisoning. Not only did they find no beneficial effects, they also reported possible... 

O Malley SS, Krishnan-Sarin S, Farren C, O Connor PG. Naltrexone-induced nausea in patients treated for alcohol dependence clinical predictors and evidence for opioid-mediated effects. J Clin Psychopharmacol 2000 20(l) 69-76. 

Grob, D., Harvey, A. M. (1958). Effects in man of the anticholinesterase compound sarin (isopropyl methyl phosphonofluoridate). Journal of Clinical Investigations, 37, 350-368. 

There have been descriptions of the acute toxic effects in humans that follow high-dose exposure (>LD5o) to the nerve agents soman (Lekov et al., 1966 Sidell, 1974), sarin (Sidell, 1974 Inoue, 1995 Nakajima et al., 1998), and VX (Nozaki et al., 1995). The same cluster of behavioral symptoms that are reported following lower doses (anxiety, psychomotor depression, intellectual impairment, and sleep disturbances) dominate the clinical picture in the immediate period following resolution of the acute toxic signs of intoxication and then slowly fade with time, sometimes taking months to fiiUy resolve. 

Application of well-known chemical agents in terrorist acts as complex compositions with other compounds may significantly to hamper their identification in the air and on the ground with use of usual analytical methods. In this case we can expect that clinical course of intoxication of victims will be atypical and curing effect of known antidotes and other medications will be brought to nothing. Practical confirmation of such application of chemical agent in terrorist purposes with use of sarin took place in Japan (Matsumoto, 1994 Tokyo Subway, 1995). 

In the early 1950s, Dr David Grob (then associated with The Johns Hopkins Hospital) and associates investigated the clinical pharmacology of sarin in an elaborate series of studies extending over several years. They administered the agent orally, intra-arterially, percutaneously and topically in the eye, and described the clinical and laboratory effects, including those on the... 

Korsak RJ, Sato MM Effects of chronic organophosphate pesticide exposure on the central nervous system. Clinical Toxicology 11 83-95, 1977 Murata K, Araki S, Yokoyama K, et al Asymptomatic sequelae to acute sarin poisoning in the central and autonomic nervous system 6 months after the Tokyo subway attack. J Neurol 244 601-606, 1997... 

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