Toxicokinetics of cyanide in rats, pigs and goats after oral dosing with potassium cyanide.

The aim of the present study was to determine the effect of the species on the toxicokinetics of cyanide and its main metabolite, thiocyanate. Forty-two rats, six pigs and six goats were dosed orally with 3.0 mg KCN/kg body weight, and cyanide and thiocyanate concentrations in blood were measured within 24 h. After the single oral dose, KCN was rapidly absorbed by rats and goats, with a time of peak concentration ( T(max)) of 15 min. The maximum plasma concentration ( C(max)) of cyanide was observed in goats (93.5 micro mol/l), whereas the C(max) of thiocyanate was higher in rats (58.1 micro mol/l). The elimination half-life ( t(1/2)) and volume of distribution ( Vd(area)) of both cyanide and thiocyanate were higher in goats (1.28 and 13.9 h, and 0.41 and 1.76 l/kg, respectively). Whereas the area under the curve (AUC) of cyanide was significantly higher in goats (234.6 micro mol.l/h), the AUC of thiocyanate was higher in rats (846.5 micro mol.l/h). In conclusion, the results of the present study support the hypothesis that the metabolism of cyanide and its main metabolite, thiocyanate, is species-linked, with the goat being more sensitive to the toxic effects of cyanide/thiocyanate.