Iohexol compared to meglumine-Ca-metrizoate in common carotid angiography. A randomized double blind cross-over study in man.

A randomized double blind cross-over study with iohexol (Omnipaque) and meglumine-Ca-metrizoate (Isopaque cerebral) was performed to answer questions concerning subjective side effects and tolerability that arose from a double blind parallel study with the same two media. The cross-over study design, with injection of the contrast media under identical conditions in the same artery, seems to be the most practical method of comparison of two well tolerated media. Iohexol showed significantly less side effects than meglumine-Ca-metrizoate. The routine premedication with atropine was neglected in this study to evaluate effects on heart rate due, for example, to the toxicity of the media. Small tachycardial and bradycardial reactions were equally divided between the media. However, a short asystolic period following the injection of meglumine-Ca-metrizoate in two different patients may indicate a higher toxicity of this medium.