Rationale and objectives: To evaluate iomeprol, a new nonionic iodinated contrast medium, as a contrast agent for myelography and to compare it with iopamidol, iohexol, and iotrolan.
Methods: An extensive clinical program was conducted on more than 600 patients to assess iomeprol's pharmacokinetics, tolerability, safety, and efficacy after intrathecal injection.
Results: Pharmacokinetics study results showed that after intrathecal administration iomeprol is completely absorbed from the cerebrospinal fluid compartment; once absorbed into the systemic circulation, it is rapidly excreted, unmetabolized, by glomerular filtration. Dose-finding studies showed that the opacification produced by iomeprol depends on the injected dose. Although a dose-dependent increase in efficacy was observed, no differences in neurotolerability and safety were detected between the doses tested. Doses of iomeprol greater than 3 g I did not cause a greater incidence of adverse events and produced significantly better contrast efficacy. Comparative clinical trials showed that iomeprol and iopamidol, iohexol, and iotrolan always provided adequate opacification of the subarachnoid space, both in conventional myelography and myelo-CT, with adequate delineation of normal structures and pathologic processes. No serious adverse events occurred up to a total dose of 4.5 g I. No differences between the agents with regard to tolerance, adverse events, and effects on vital signs, physical examination, and neurologic examination were observed.
Conclusions: Iomeprol is safe and effective and can be recommended for myelography and myelo-CT.