Clinical trial of iopamidol for lumbosacral myelography

The results of the initial North American trial of the nonionic, water-soluble contrast medium lopamidol for lumbosacral myelography are reported. The lopamidol was easily visualized by fluoroscopy during introduction, and the radiographic quality of all 12 conventional myelographic examinations was excellent. The diagnoses were herniated nucleus pulposus (seven), traumatic dislocation (one), metastasis (one), and normal (three). One patient had a repeat myelogram with a different hydrosoluble contrast medium 2 months after his lopamidol examination and surgery and showed no radiographic evidence of arachnoiditis. The adverse reactions were all mild and transient: headache (four cases), nausea (two), and leg pain (one). There were no diaphoresis, fever, seizures, hallucinations, agitation, or vital sign changes. Electrocardiography, hematology, and blood chemistries were all normal. In two patients, electroencephalogram changes, three to four bursts of diffuse intermittent rhythmic delta activity with no spiking, were present at 6 hr with return to normal at 24 hr.