Plasma level and renal excretion of iotrolan after lumbar injection in patients.

Ten milliliters of iotrolan containing 240 mg I/ml were injected into the lower lumbar subarachnoid space of ten patients. Plasma level and urinary and fecal excretion were monitored for 3 days after injection. The mean iodine concentration in the plasma of about 50 micrograms/ml (6% of the dose given in the total plasma volume) peaked at 1 to 2 hours after injection. After reaching the maximum values, the iotrolan concentration in the plasma decreased with a half-life of about 4 hours (median value). About 90% of the injected dose was found in the urine and about 1% was detected in the feces.