Viscosity of iodinated contrast agents: significance for peripheral venous injection

The meglumine salt of a urographic contrast agent is significantly more viscous than the comparable sodium salt. To noninvasively deliver a bolus to some patients it is often necessary to use a 21-gauge needle. The inherent resistance of a 21-gauge scalp needle results in approximately a 60% increase in injection time for the meglumine salt as opposed to the sodium salt.