Which of the following is an example of a High-Osmolar contrast medium?

• A. iodixanol (Visipaque)
• B. diohexol (Hypaque)
• C. iohexol (Omnipaque)
• D. iopamidol (Isovue)

Answer: (B)

High-osmolar contrast media (HOCM) are characterized by their relatively high osmolarity due to the presence of multiple iodine atoms in their structure. These contrast agents can increase the risk of adverse reactions due to their osmotic effects on the body’s tissues and fluids.

Diohexol, commonly known by the trade name Hypaque, is indeed an example of a high-osmolar contrast medium. It has a higher osmolarity compared to low-osmolar contrast agents, which can cause more significant physiological changes such as vascular expansion and potential discomfort upon injection. This can lead to complications, especially in patients with pre-existing conditions.

In contrast, the other agents listed, including iodixanol, iohexol, and iopamidol, are classified as low-osmolar contrast media (LOCM). These newer agents tend to have lower osmolarity, which generally results in fewer adverse reactions and improved patient safety profiles during diagnostic imaging procedures. Understanding the osmolarity of contrast media is essential for optimal patient care, especially in managing potential allergic reactions or kidney-related issues.