Elimination of iohexol, a low osmolar nonionic contrast medium, by hemodialysis in patients with chronic renal failure.

The dialyzability of iohexol was examined in patients with chronic renal failure on long-term hemodialysis treatment. Eight patients had iohexol (Omnipaque 240 or 350 mg I/ml) injected in doses between 98 and 1,493 mg I/kg body weight (BW) 25 h (mean time) before start of hemodialysis. Dialysance of iohexol was 81 +/- 15 ml/min (mean +/- SD) compared to 120 +/- 16.8 ml/min for creatinine. Elimination half-life for iohexol during hemodialysis was 3.9 +/- 1.1 h while plasma clearance was 64 +/- 17 ml/min. The distribution volume calculated (0.25 +/- 0.05 liters/kg BW) confirms previous observations with distribution in the extracellular fluid only. Before the start of hemodialysis 36 +/- 28% of the dose injected was eliminated, indicating some extrarenal elimination. After 4 h of hemodialysis 72 +/- 11% of the dose was removed.