Diatrizoate distribution in dogs as a function of administration rate and time following intravenous injection

In this study, we determined diatrizoate concentrations in plasma and the extravascular space in dogs following an injection of the same dose of diatrizoate under three different conditions: (A) subsequent to a rapid bolus injection of diatrizoate: (B) subsequent to a bolus injection followed by an intravenous drip infusion; and (C) subsequent to a slow intravenous drip infusion. The data indicate that the highest plasma level occurred immediately after bolus injection (A). Significantly more diatrizoate was present in plasma 10 to 25 min from the start of an intravenous drip infusion given over 12.5 min (C) than when the same dose was given as a rapid bolus (A). The slow infusion method also resulted in significantly higher diatrizoate plasma levels from 15 to 25 min when compared to the bolus plus drip method (B). The differences in the calculated extravascular concentrations were insignificant among the three groups once all of the contrast material had been infused, i.e., after 12.5 min. The results are discussed in terms of their practical application to cranial computed tomography.