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ÁLVARO DOMÍNGUEZ GIL AN. R. ACAD. NAC. FARM.

Physical and chemical constants are studied and also the advantages that the
non ionic contrasts present over the ionic ones.

The possible undesirable collateral effects due to an intravenous injection are
described in a small but important number of patients.

Key words: Iodine contrast.— Ionic.— No ionic.— Diatrizoic Acid.— Iohexol.

EXTENSIVE ABSTRACT

The aim of the radiological contrasts has the mission to visualize the internal
structures of our organism that are not generally visible to the rays X for having
a radiological density to the next tissues.

To avoid the toxicity of the free iodine, in the radiological compounds the
iodine is joined to the ring benzoic, so the atom of iodine remains strongly joined
to other atoms, being avoided its sensitive aggressiveness.

The most used organic compounds are acids with three or six atoms of iodine,
being those that confer him the opacity. The density, viscosity, solubility and to-
lerance will depend on the radicals that have been incorporated.

Chemically, a benzoic ring constitutes all of them whose positions, 2, 4 and
6 have three atoms of iodine. In position 1, they have a group COOH partially
responsible of the product’s solubility. In positions 3 and 5, they have two radicals
on which, it depend the toxicity and tolerance.

There are been studied of preference the acids Diatrizóic, Iotalámic and Metri-
zóic, as well as the acids Ioxaglic and Iocarmic among the ionic ones. Among those
no ionics, the Metrizamida and the Iohexol.

The intravascular injection of the iodine contrasts mediums, especially the io-
nic ones due to their hyper tonicity, they can produce undesirable collateral effects
in a small but important number of patients. When such reactions are serious, they
constitute a risk for the patient and therefore to be able to predict them. Then, to
know them and to treat is very important for the radiologists that carry out these
explorations.

The possible secondary reactions are classified in three levels: Light, moderate
and serious.

INTRODUCCIÓN

El objetivo de los contrastes radiológicos iodados tiene como
misión visualizar estructuras internas de nuestro organismo que
generalmente no son visibles a los rayos X por tener una densidad
radiológica similar a los tejidos próximos.

Normalmente en la exploración radiológica sólo se diferencian
bien aquellas estructuras que tienen muy distinta opacidad, tal su-
cede con los huesos (más opacos), o el tejido pulmonar (menos

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