The concentration of
thiocyanate in the serum of eight test subjects with
renal failure and seven healthy control subjects was measured, as it declined with time, after oral doses of
thiocyanate or i.v.
injections of
nitroprusside had been administered. Additional measurements were taken, on the healthy subjects only, of the concentrations of
thiocyanate in the urine, and also of the influence of an increased
chloride intake on the rate of elimination of
thiocyanate. For the healthy subjects an elimination half-life of between one and five days (mean c. 3 days) was found. Increasing the
chloride elimination rate to approximately twice normal did not significantly speed up the rate of
thiocyanate elimination. The amounts of
thiocyanate which had been administered as doses reappeared almost exclusively in the urine. For the subjects with
renal failure, the elimination half-life had a mean value of approximately nine days. The elimination constants were found to be proportional to the
creatinine-clearance rates. The ke value at a
creatinine-clearance of zero ml/min was approximately 15% of the ke value at a
creatinine-clearance rate of 120 ml/min. The distribution volumes for
thiocyanate were greater for the patients with
renal failure than for the healthy subjects. The conclusions for
therapies using
nitroprusside are discussed.