Evaluation of lopamidol and diatrizoate in excretory urography: a double-blind clinical study

Image opacification, patients' tolerance, and clinical and laboratory findings were evaluated in patients having excretory urography at three centers. In a double-blind, parallel study, iopamidol was compared with diatrizoate (50-ml dose), and in an open-label trial, the administration of a 100-ml dose of iopamidol was evaluated. In the double-blind study, a total of 84 patients received 50 ml of either iopamidol or diatrizoate. In the open-label study, another 42 patients received a 100-ml dose of iopamidol. Image opacification scores after the administration of the 50-ml doses showed better opacification with iopamidol than with diatrizoate in the renal calices (p less than .05) and in the composite kidney (p less than .05). Opacification scores were higher for 100-ml doses of iopamidol than for 50-ml doses in all anatomic regions as well as in the composite kidney (p = .0001). Patients' tolerance to iopamidol was significantly better than their tolerance to diatrizoate (p less than .025). Investigators observed adverse drug reactions in a total of 10 patients. In the double-blind study, one of 43 patients had transient bradycardia after the administration of iopamidol. In the same study, four of 41 patients who received diatrizoate had five minor adverse drug reactions. With 100-ml doses of iopamidol, five of 42 patients had adverse reactions. No adverse side effects required therapy in either study. There were no significant changes in vital signs or laboratory values after drug administration. The results of this study show that iopamidol is a suitable agent for excretory urography at doses of 50 and 100 ml. Patients report fewer unpleasant side effects with iopamidol than with diatrizoate. Overall image quality was better with iopamidol than with diatrizoate. Overall evaluation of drug performance was better with iopamidol than with diatrizoate.