Acetrizoic acid is a pharmaceutical drug that was used as an

iodinated contrast Iodinated contrast is a form of intravenous radiocontrast agent containing iodine, which enhances the visibility of vascular structures and organs during radiographic procedures. Some pathologies, such as cancer, have particularly improved visib ...

medium for

X-ray imaging Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeut ...

. It was applied in form of its salt, sodium acetrizoate, but is no longer in clinical use.

Chemistry and mechanism of action

The substance has high

osmolality Molality is a measure of the number of moles of solute in a solution corresponding to 1 kg or 1000 g of solvent. This contrasts with the definition of molarity which is based on a specified volume of solution. A commonly used unit for molali ...

and is

water-soluble In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solub ...

. The three iodine atoms in the molecule readily absorb X-rays and are therefore responsible for its usability as a contrast medium.

History

Acetrizoate was developed by V.H. Wallingford of

Mallinckrodt Mallinckrodt Pharmaceuticals is an American-Irish domiciled manufacturer of specialty pharmaceuticals (namely, adrenocorticotropic hormone), generic drugs and imaging agents. In 2017 it generated 90% of its sales from the U.S. healthcare system. ...

, and introduced in 1950; it was employed as a contrast agent for several radiographic studies, including

pyelography Pyelogram (or pyelography or urography) is a form of imaging of the renal pelvis and ureter. Types include: * Intravenous pyelogram – In which a contrast solution is introduced through a vein into the circulatory system. * Retrograde pyelogram ...

angiography Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is perfor ...

of the

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a ve ...

carotid In anatomy, the left and right common carotid arteries (carotids) (Entry "carotid"
in
aorta The aorta ( ) is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes o ...

, and

cholecystography Oral cholecystography is a radiological procedure used to visualize the gallbladder and biliary channels, developed in 1924 by American surgeons Evarts Ambrose Graham Evarts Ambrose Graham (1883–1957) was an American academic, physician, and ...

. It was soon found to be highly toxic to the

kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...

s and

nervous system In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes ...

—work urging caution in its administration was published as early as 1959, after reports of adverse reactions ranging from hypersensitivity to brain damage—and was eventually replaced by other agents with higher efficacy and lower toxicity, such as sodium diatrizoate, a closely related compound.

Trade names

Trade names include Urokon, Triurol and Salpix, as well as Gastrografina and Urografina in Portugal.

References

Iodobenzene derivatives Radiocontrast agents Acetanilides Benzoic acids {{pharma-stub