Lumbar myelography with iohexol in outpatients: prospective multicenter evaluation of safety.

A multicenter open, noncomparative evaluation of the safety of iohexol was prospectively conducted in 81 adult outpatients undergoing screen-film lumbar myelography. Iohexol (180 milligrams of iodine per milliliter) was administered via a lumbar route at a dose of 8-17 mL. Computed tomography (CT) was performed after myelography. The safety of iohexol was assessed by monitoring adverse reactions and neurologic status and by measuring vital signs and serum laboratory values. The most frequent adverse reaction was headache (16 of 81 patients [19.7%]). Twelve patients complained of a headache on the day of the myelographic procedure, and four patients reported a headache 24 hours after the procedure. Nausea or vomiting occurred in four of 81 patients (4.9%) only on the day myelography was performed. No other neurologic abnormalities were found. Iohexol produced myelographic and CT studies of good to excellent quality in all patients. This study indicates that iohexol can be employed safely in lumbar myelography of adult outpatients.