THE NONIONIC DIMERS - SOME THEORETICAL AND CLINICAL CONSIDERATIONS

The non-ionic dimers are probably the closet approach yet to the 'ideal' contrast agent - an agent which demonstrates no significant effects on the body. The particular characteristics of such dimers are reviewed. Effects related to osmolality, which include pain and heat sensations, vasopressin-dependent nephrotoxic potential and hypervolemia, are all minimized due to the iso-osmolality of dimer formulations. Contrast density tends to be better in some applications due to reduced osmotic dilution, and osmotic diuresis is low, resulting in denser pyelograms. High hydrophilicity and lack of charge reduce molecular or chemotoxicity and, as a result of the combination of low osmolality and low chemotoxicity, both systemic and organ-specific toxicities are very low. Consequently, the dimers are likely to become the agents of choice in high dose diagnostic and interventional radiological procedures.