Ouabain pharmacokinetics in dog and man. Determination by radioimmunoassay.

venous administration of ouabain to human subjects for 9 consecutive days resulted in the establishment of a plateau of plasma concentration and urinary excretion after 4-5 days, confirming plasma and urinary half-lives in the 19-24-hour range. The mean ratio of renal clearance of ouabain to that of creatinine was 0.81 in the human subjects. The plasma half-life of ouabain determined in these studies is in good agreement with previous observations of the half-life of dissipation of positive inotropy and of slowing of ventricular response to atrial fibrillation after ouabain administration.