Metrizoic acid is a

pharmaceutical drug A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and re ...

that was used as an iodinated contrast medium for X-ray imaging. Its uses included angiography (imaging of blood vessels and heart chambers) and

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

(imaging of the urinary tract), but it has been discontinued, at least in the US. It was used in form of its salts, metrizoates. Due to its high osmolality, metrizoic acid had a risk of inducing allergic reactions higher than that of lower osmolar contrast media.

Chemistry

The iodine content of metrizoate ranged from 370 mg/ml to 440 mg/ml, with osmolarity has high as 2100 mOsm/kg. The viscosity is 3.4 cP at 37 degree Celsius (human body temperature).

Adverse effects

Side effects of metrizoate are: urticaria, headache, nausea, vomiting, dizziness, and hypotension. Other side effects include minor electrocardiographic changes such as tachycardia, bradycardia, and inversion of T waves.

References

Benzoic acids Iodoarenes Radiocontrast agents Acetanilides {{pharmacology-stub