Neurotoxicological and behavioral effects of cyanide and its potential therapies

The use of the blood agent cyanide (CN) as a military threat agent has been recognized not only historically (Nero and Napoleon III) but also more currently in World War I, World War II, in the Iran-Iraq War in the 1980s, and elsewhere where terrorist activities have occurred. CN is easy and inexpensive to produce and can be obtained from normal commercial trade. CN can act very rapidly (within seconds) to prevent the normal utilization of oxygen by tissues. Excitable tissues, for example, heart and brain, are particularly affected. Hypoxia, convulsions, heart arrhythmias, and death can follow. If exposed, it is best to leave the affected area rapidly. Treatments such as nitrite, which forms methemoglobin that binds CN, and thiosulfate, which converts CN to thiocyanate, act within an appropriate time but produce central nervous system side effects. This article examines the literature on the neurotoxicological and behavioral effects of CN and its treatments. Sites and mechanisms of actions involved in these effects are evaluated. Factors that significantly alter the action of CN and may influence morbidity and mortality are discussed.