The Choice of the Iodinated Radiographic Contrast Media to Prevent Contrast-Induced Nephropathy

Table 1

Iodinated contrast media used in clinical practice.

Name	Type	Iodine content	OSM	Osmolality	Viscosity
		mg/mL	mOsm/kg	type	Cps at 37°C
Ionic
Diatrizoate (Hypaque 50, Renografin)	Monomer	300	1,550	HOCM	10.5
Metrizoate (Isopaque 370)	Monomer	370	2,100	HOCM	3.4
Iothalamate (Conray)	Monomer	325	1843	HOCM	4.0
Ioxaglate (Hexabrix)	Dimer	320	580	LOCM	7.5
Nonionic
Iopamidol (Isovue-370)	Monomer	370	796	LOCM	9.4
Iohexol (Omnipaque 350)	Monomer	350	884	LOCM	10.4
Iodixanol (Visipaque 320)	Dimer	320	290	IOCM	11.8
Iotrolan (Isovist)	Dimer	300	320	IOCM	8.1
Ioxaglate (Hexabrix)	Dimer	320	600	LOCM	7.5
Ioxilan (Oxilan 350)	Monomer	350	695	LOCM	8.1
Iopromide (Ultravist 370)	Monomer	370	774	LOCM	10.0
Ioversol (Optiray 300)	Monomer	300	651	LOCM	5.5
Iomeprol (Iomeron 350)	Monomer	350	618	LOCM	7.5

Ionic and nonionic contrast media may be monomeric or dimeric; 3 iodine atoms are delivered with each benzene ring of a contrast medium: if a contrast molecule contains only 1 benzene ring, it is called a monomer; if it contains 2 benzene rings, it is called a dimer. In a solution, ionic contrast media break up into their anion and cation components, thereby increasing osmolality, while nonionic contrast media do not break up in solution. Nonionic dimers are the ideal contrast media as they deliver the most iodine with the least effect on osmolality.
The osmolality of contrast media is compared with the osmolality of plasma. HOCM = high osmotic contrast media have the highest osmolality, that is, 5–8 times the osmolality of plasma. LOCM = low osmotic contrast media have an osmolality still higher than plasma, that is, 2-3 times the osmolality of plasma. IOCM = isoosmotic contrast media have the same osmolality as plasma. Cps: viscosity in centipoise.
Most data of viscosity are from [118].
(Reproduced and modified from [8], with permission)