Safety and toleration of the non-ionic contrast medium iopentol. An intravenous phase I trial

The safety and toleration of iopentol, a new non-ionic contrast medium for intravascular use, were evaluated. In the intravenous phase I study, 24 volunteers were allocated to 3 dose groups corresponding to 0.3, 0.6 or 1.2 g I/kg body weight, respectively. Injection of saline was used as control in the highest dose group. Adverse events, hemodynamic parameters, and clinical chemical parameters in the blood and urine were recorded. No severe or unexpected adverse events occurred. All findings were transient and included a sensation of warmth, a small increase in heart rate, a dilution effect on blood parameters, and enzymuria. The deviations in clinical chemical parameters fell mostly within reference ranges and were clinically insignificant. Thus, iopentol may safely be advanced to clinical trials in patients for comparative studies.