Iopamidol vs. metrizamide myelography: clinical comparison of side effects.

One hundred myelographies with iopamidol and 100 with metrizamide were performed in order to compare the side effects of the two contrast media after injection into the spinal subarachnoid space. All patients were observed for a follow-up period of at least 4 days. The most frequently observed side effect, headache, was more common, of longer duration, and more severe with the use of metrizamide than with iopamidol. Only neck pain was more common with iopamidol. More severe side effects such as meningeal irritation, psychoorganic syndrome, and epileptic seizures occurred only with metrizamide. The results seem to indicate a lower neurotoxicity and better patient tolerance for iopamidol than for metrizamide.