PRECLINICAL SAFETY ASSESSMENT OF IOMEPROL FOR INJECTION AS CONTRAST-MEDIUM FOR MYELOGRAPHY

A series of pharmaco-toxicological investigations were carried out in animals in order to assess the neurotolerance of iomeprol, a new nonio nic iodinated contrast medium. After intrathecal administration iomepr ol was completely eliminated from the cerebrospinal fluid, rapidly cle ared from the plasma and excreted unchanged through the kidneys. When administrated intrathecally, iomeprol did not significantly alter the behavioural functions or the physiological activities of the brain. Un like other contrast media, iomeprol was devoid of any epileptogenic ac tivity. The acute neurotoxicity of iomeprol was comparable with that o f iopamidol, but less than that of iohexol, iotrolan and iodixanol. Io meprol was well tolerated in both rats and dogs following weekly intra thecal administrations for four weeks of doses up to three times highe r than those foreseen for clinical use. High neurotolerance in animals and favourable physico-chemical characteristics make iomeprol particu larly suitable as a contrast medium for both myelography and cerebral ventriculography.