[Contrast medium reaction to iohexol (Omnipaque) with monocyte activation demonstrated in vivo]

A contrast reaction to the intravenous injection of the non-ionic contrast medium iohexol (Omnipaque) is reported. The symptoms developed several hours after the injection and at first were not recognised as being due to the contrast. The reaction could be reproduced under controlled conditions and was associated with a significant rise in thromboplastin synthesis in circulating monocytes, a sign of marked cellular activation.