iothalamate-meglumine and Bradycardia

Metrizamide, a non-ionic contrast medium of low osmolality was compared with meglumine ioxithalamate, the ionic angiographic contrast medium currently in use in our department in a double-blind study. Criteria upon which the comparison was based were: 1) the pain reaction of the patient upon intra-arterial contrast injection, 2) bradycardial reactions upon common carotid injection and 3) the quality of the contrast image. Metrizamide induced significantly less painful sensations than meglumine ioxithalamate in those vessels in which injections of contrast medium are frequently painful (external carotid artery, vertebral artery). No significant difference in the degree of bradycardia was caused by the two contrast media. The degree of bradycardia was also found to be poorly reproducible upon successive injections of the same contrast medium in the same patient, thus raising questions as to the suitability of this method for determining the toxicity of the contrast medium. The quality of the angiograms obtained did not differ significantly with the two media. Spasm, when it occurred during selective external carotid injections, was found to be independent of the contrast agent used, being correlated instead with the depth of distal advance of the catheter tip into the external carotid. Of the 51 patients included in the study, two patients suffered transient neurological deficit after angiography with metrizamide, and one patient suffered a permanent hemiplegia after angiography with meglumine ioxithalamate.

Topics: Aorta, Thoracic; Bradycardia; Carotid Arteries; Catheterization; Cerebral Angiography; Clinical Trials as Topic; Humans; Iothalamate Meglumine; Metrizamide; Pain; Vertebral Artery

Selective left vertebral angiography was carried out in 21 rabbits comparing the toxic effects of meglumine iothalamate (Conray meglumine), meglumine metrizoate (Isopaque Cerebral) and metrizamide (Amipaque). The iodine concentration for all 3 media was 280 mg/ml. General convulsions were seen in many of the animals with all 3 media. The convulsions occurred at higher doses and were milder with metrizamide than with the 2 other contrast agents. Bradycardia was also seen with all 3 media and there was no statistical significant difference between them in this respect. The mortality was approximately 50% with both meglumine iothalamate and meglumine metrizoate, while no animals died following angiography metrizamide.

Topics: Angiography; Animals; Bradycardia; Contrast Media; Female; Injections, Intra-Arterial; Iodobenzoates; Iothalamate Meglumine; Male; Metrizamide; Metrizoic Acid; Rabbits; Seizures; Vertebral Artery