Comparison of the Nonionic Contrast Agent Iopamidol and an Ionic Contrast Agent in Aortofemoral and Peripheral Arteriography

The tolerability of iopamidol (300 mg I/ml, 616 mOsm/kg H2O) and that of sodium megiumine diatrizoate (292 mg I/ml, 1420 mOsm/kg H2O) were compared in a double-blind trial involving 54 patients undergoing aortofemoral and peripheral arteriography. Among the 27 patients studied with iopamidol, 4 showed evidence of pain (3 mild and 1 moderate); of the 27 patients receiving diatrizoate, 17 (62%) had evidence of pain (9 mild, 6 moderate, and 2 extreme). The average subjective perception of pain (visual analog scale 0–12) among the iopamidol patients was 0.6; of the diatrizoate patients, it was 4.75 (P < 0.001). The average subjective perception of warmth (scale 0–10) among the iopamidol patients was 4.25; among the diatrizoate patients it was 7.1 (P < 0.001). In this study iopamidol was better tolerated than the ionic agent sodium meglumine diatrizoate. Nonionic contrast agents may replace currently used ionic agents for peripheral arteriography.