Pharmacokinetics and tolerability of iopromide 240 after lumbar myelography

To evaluate the pharmacokinetics and tolerability of iopromide 240 mg iodine/mL after intrathecal administration.

Eleven patients with an indication for lumbar myelography received 10 mL iopromide 240 in an open, prospective, single-center study. All patients were followed 72 hours after the procedure and remained in the hospital. Urine was sampled from before the myelography up to 72 hours after the procedure in stages (range, 0-6, 6-12, 12-24, 24-48, and 48-72 hours). Iodine plasma levels were determined before and 30 minutes, 1 hour, 2 hours, 4 hours, 6 hours, 9 hours, 12 hours, and 24 hours after the administration of iopromide 240. Vital signs were measured at baseline, before, and 1 and 24 hours after the procedure. Physical and neurologic examinations were performed in all patients at baseline and at the end of the study period; all adverse events were recorded. The results were subject to pharmacokinetic analysis using compartment model-independent and -dependent methods.

Ten of 11 patients had measurable iodine plasma levels. After a lag time of approximately 0.6 hours (mean value), maximum iodine concentrations of 45% of the administered dose per total plasma volume were observed after 3.8 hours. Plasma half-lives ranged from 3.0 to 60.5 hours (model-independent methods) with a mean of 14.9 hours and a standard deviation of 17.0 hours. Using curve fitting with an open one-compartment model revealed good agreement with the model-independent methods (half-life 17.3 hours). The recovery of iodine in urine in the 72-hour period was 78%+/-15% (range, 53%-94%) as a result of an undeterminable loss of urine in some patients and prolonged half-lives in two patients. Only one patient had adverse events 24 hours after myelography.

After lumbar myelography, iopromide 240 is almost completely excreted renally within 72 hours, with a prolonged half-life as a result of the route of administration. The kinetics of iopromide 240 after intrathecal administration are characterized by a prolonged half-life. The safety of the contrast medium was confirmed.