Iopamidol (DB08947): A Comprehensive Monograph on a Non-Ionic, Low-Osmolar Radiographic Contrast Agent

Executive Summary

Iopamidol is a second-generation, non-ionic, low-osmolar iodinated radiographic contrast agent, representing a significant advancement in safety and tolerability over the first-generation ionic contrast media. As a small molecule diagnostic agent, its fundamental mechanism of action is the physical attenuation of X-rays, a property conferred by the three iodine atoms covalently bound to its benzene ring core. This allows for enhanced visualization of vascular structures, organs, and other non-bony tissues during diagnostic imaging procedures.

Developed by Bracco and marketed primarily under the brand name ISOVUE, Iopamidol has a broad spectrum of U.S. Food and Drug Administration (FDA)-approved indications. It is a workhorse agent in modern radiology, utilized extensively for intra-arterial and intravenous procedures, including cerebral, peripheral, and coronary angiography, as well as contrast-enhanced computed tomography (CECT) of the head and body in both adult and pediatric populations. Specific formulations, designated ISOVUE-M, are approved for intrathecal use in neuroradiology.

The clinical pharmacology of Iopamidol is characterized by its biological inertness. Its pharmacokinetic profile is defined by an open two-compartment model with a plasma half-life of approximately two hours in patients with normal renal function. Following intravascular administration, it distributes rapidly throughout the extracellular fluid without significant protein binding or metabolism. Elimination is almost exclusively via renal excretion, with the drug being cleared from the body chemically unchanged.