Comparison of the relative propensities of isoamyl nitrite and sodium nitrite to ameliorate acute cyanide poisoning in mice and a novel antidotal effect arising from anesthetics.

Isoamyl nitrite has previously been considered acceptable as an inhaled cyanide antidote; therefore, the antidotal utility of this organic nitrite compared with sodium nitrite was investigated. To facilitate a quantitative comparison, doses of both sodium nitrite and isoamyl nitrite were given intraperitoneally in equimolar amounts to sublethally cyanide-challenged mice. Righting recovery from the knockdown state was clearly compromised in the isoamyl nitrite-treated animals, the effect being attributable to the toxicity of the isoamyl alchol produced during hydrolysis of the isoamyl nitrite to release nitrite anion. Subsequently, inhaled aqueous sodium nitrite aerosol was demonstrated to ameliorate sublethal cyanide toxicity, when provided to mice after the toxic dose, by the more rapid recovery of righting ability compared to that of the control animals given only the toxicant. Aerosolized sodium nitrite has thus been shown by these experiments to have promise as a better alternative to organic nitrites...