Diatrizoate: A Comprehensive Monograph on a Foundational High-Osmolality Iodinated Radiocontrast Agent

I. Executive Summary

Diatrizoate, also known by the chemical name amidotrizoate, is a foundational small-molecule diagnostic agent that has been a cornerstone of radiological imaging for decades. Approved for medical use in the United States in 1954, it represents one of the first-generation ionic, high-osmolality iodinated radiocontrast agents.[1] Its primary and essential function is to enhance the visibility of internal anatomical structures, fluids, and pathologies during X-ray-based diagnostic procedures, including conventional radiography, fluoroscopy, and computed tomography (CT).[1]

The mechanism of action for Diatrizoate is fundamentally physical rather than pharmacological. The molecule's structure incorporates three heavy iodine atoms, which possess a high atomic number and electron density. This configuration allows the compound to effectively absorb, or attenuate, X-ray photons, thereby creating a stark contrast between the agent-filled space and surrounding soft tissues.[2] This property of radiopacity is the basis for its utility in a vast array of diagnostic applications.

Clinically, Diatrizoate is utilized in multiple formulations, most commonly as its highly water-soluble sodium and meglumine salts, or as a combination of the two.[6] This versatility allows for administration via several routes—including oral, rectal, intravenous, and direct instillation—enabling the visualization of the gastrointestinal tract, the urinary system, blood vessels, and other body cavities.[1] It serves as a critical alternative to barium sulfate for gastrointestinal studies in cases of suspected perforation.[1]