Metrizoic acid

Metrizoic acid is a molecule used as a contrast medium. It present a higher risk of allergic reactions due to its high osmolality. Its approval has been discontinued by the FDA. One study in 1976 demonstrated that metrizoic acid, when used for cardiac angiography, was well tolerated. A total of 10, 000 injections were administered to 2,028 patients undergoing angiocardiographic procedures over a three-year period. With two exceptions, all complications occurred during injection of the right coronary artery. Seven cases of ventricular fibrillation, and 5 of significant bradycardia/asystole, were associated with metrizoic acid injection. In general, the drug was well tolerated by patients during cardiac examinations [A32091].