Routine clinical experiences using urokon sodium 70% in intravenous urography.

Abstract

The introduction by Swick (27) in 1929 of excretory urography as a procedure for roentgenographic visualization of the urinary tract has led to improved clinical evaluation of renal function and diagnosis of renal lesions. During the past twenty years many new substances have been used as contrast media for diagnostic roentgenologic technics. This paper reviews our experience with Urokon Sodium 70%, a new contrast medium for excretory urography recently developed in the research laboratory of the Mallinckrodt Chemical Works. Urokon Sodium 70% is a sodium salt of 3-acetylamino-2,4,6-triiodobenzoic acid. It is reported to have the following structural formula, and to contain 65.8 per cent iodine per molecule (32). A number of earlier reports on the clinical use of this substance for intravenous injection as a 30 per cent solution for excretory urography indicate a lower incidence of severe side reactions than encountered with other compounds now widely used for the procedure. Pyelograms obtained following the intravenous injection of Urokon Sodium 30% have been said to be at least equal in quality to those obtained with other media (16, 21, 23). There have been a few reports on the clinical trial of Urokon Sodium 70% as a contrast medium for intravenous injection in cardioangiography (9) and translumbar aortography (14). Because of its high iodine content, excellent nephrograms and pyelograms were obtained when the substance was used for excretory urography (31). Table I indicates the relative iodine content available in concentrated form in three iodinated organic compounds. Animal Experiments The original pharmacological studies on Urokon Sodium 70% by Seevers (29) indicated an exceedingly low toxicity in the dog and monkey. Porporis and Mueller (20) have carried out some investigations on renal functions in dogs before and after rapid intravenous infusions of Urokon Sodium 70% at high dose levels. One of 3 animals survived a dose level of 5 gm. per kilogram of body weight. Para-aminohippuric acid (PAH) and inulin clearances before Urokon infusions and thirty minutes and twenty-four hours after Urokon infusions, at dose levels of 5 and 2.5 gm. per kilogram are given in Table II. The results obtained at a dose level of 2.5 gm./kg. parallel those obtained with 4 other animals. PAH clearance thirty minutes following rapid intravenous administration of Urokon Sodium 70% at a dose level of 5 gm./kg. resulted in complete inhibition of tubular secretion of PAH with no change in the inulin clearance. At a dose level of 2.5 gm./kg. a decrease in tubular secretion of PAH varied between 80 and 100 per cent with no change in inulin clearance. Twenty-four hours after infusion at both of these dose levels, the PAH clearance was normal. In normal dogs the clearance of Urokon at massive dose levels seems to be approximately that of the inulin clearance, and it is probable that much of the excreted Urokon is essentially a glomerular filtrate.