RESUMO
The pharmacokinetic characteristics of iodamide, a contrast agent for excretion urography, were studied in seven normal subjects and in 15 patients with various degrees of renal impairment. Two different formulations were administered, namely, a 65% solution (iodamide 300) by slow intravenous injection and a 24% solution by slow intravenous (drip) infusion. Both preparations of iodamide exhibited characteristics of an open two-compartment model. In both normal subjects and patients, the contrast agent was excreted almost exlusively in urine. In normal subjects, the pharmacokinetic parameters of both formulations were similar, with a distribution half-life (1/2alpha) of about 3 minutes and a disposition half-life (t1/2beta) of about 69 minutes. An average of 84 per cent of the dose was excreted in urine within 4 hours after administration of iodamide with net renal tubular secretion of about 38 per cent. The binding of iodamide to plasma proteins was negligible, and the extent of biotransformation of iodamide was minimal. In patients with renal impairment, the disposition half-life (t1/2beta) of iodamide ranged from 4.1 to 16.4 hours. Other changes in pharmacokinetic parameters were also seen in patients with renal impairment.