Iohexol

Iohexol, sold under the trade name Iodaque among others, is a contrast agent used for X-ray imaging.^[3] This includes when visualizing arteries, veins, ventricles of the brain, the urinary system, and joints, as well as during computed tomography (CT scan).^[3] It is given by mouth, injection into a vein, or into a body cavity.^[4]

Iohexol

Clinical data
Trade names	Iodaque, Hexopaque, Oraltag, others
Other names	5-[N-(2,3-Dihydroxypropyl)acetamido]-2,4,6-triiodo-N,N'-bis(2,3-dihydroxypropyl)isophthalamide
AHFS/Drugs.com	Micromedex Detailed Consumer Information
License data	US DailyMed: Iohexol
Routes of administration	Intrathecal, intravascular, by mouth, intracavital, rectal
ATC code	V08AB02 (WHO)
Legal status
Legal status	CA: ℞-only[1][2] US: ℞-only In general: ℞ (Prescription only)
Pharmacokinetic data
Protein binding	Low
Metabolism	Nil
Elimination half-life	Variable
Excretion	Kidney, unchanged
Identifiers
IUPAC name 1-N,3-N-Bis(2,3-dihydroxypropyl)-5-[N-(2,3-dihydroxypropyl)acetamido]-2,4,6-triiodobenzene-1,3-dicarboxamide
CAS Number	66108-95-0 Y
PubChem CID	3730
DrugBank	DB01362 Y
ChemSpider	3599 Y
UNII	4419T9MX03
KEGG	D01817 Y
ChEBI	CHEBI:31709 Y
ChEMBL	ChEMBL1200455 N
CompTox Dashboard (EPA)	DTXSID6023157
ECHA InfoCard	100.060.130
Chemical and physical data
Formula	C19H26I3N3O9
Molar mass	821.142 g·mol−1
3D model (JSmol)	Interactive image
Melting point	174 to 180 °C (345 to 356 °F)
SMILES O=C(N(c1c(I)c(c(I)c(c1I)C(=O)NCC(O)CO)C(=O)NCC(O)CO)CC(O)CO)C
InChI InChI=1S/C19H26I3N3O9/c1-8(29)25(4-11(32)7-28)17-15(21)12(18(33)23-2-9(30)5-26)14(20)13(16(17)22)19(34)24-3-10(31)6-27/h9-11,26-28,30-32H,2-7H2,1H3,(H,23,33)(H,24,34) Y Key:NTHXOOBQLCIOLC-UHFFFAOYSA-N Y
NY (what is this?)  (verify)

Side effects include vomiting, skin flushing, headache, itchiness, kidney problems, and low blood pressure.^[3] Less commonly allergic reactions or seizures may occur.^[3] Allergies to povidone-iodine or shellfish do not affect the risk of side effects more than other allergies.^[5] Use in the later part of pregnancy may cause hypothyroidism in the baby.^[6] Iohexol is an iodinated non-ionic radiocontrast agent.^[3] It is in the low osmolar family.^[7]

Iohexol was approved for medical use in 1985.^[8] It is on the World Health Organization's List of Essential Medicines.^[9][4]

Chemistry

The osmolality of iohexol ranges from 322 mOsm/kg—approximately 1.1 times that of blood plasma—to 844 mOsm/kg, almost three times that of blood.^[10] Despite this difference, iohexol is still considered a low-osmolality contrast agent; the osmolality of older agents, such as diatrizoate, may be more than twice as high.^[11]

Adverse effects

The most common side effects after intravenous injections are: pain at the site of injection (3%), blurring of vision (2%), nausea (2%), arrhythmia (2%), taste perversion (1%), hypotension (0.7%), and vomiting (0.7%).^[12]

Society and culture

Naming

It is sold under the brand name Omnipaque.^[13] It is also sold as a density gradient medium under the names Accudenz, Histodenz, and Nycodenz.^[14][15]

Available forms

It is available in various concentrations, from 140^[12] to 350^[16] milligrams of iodine per milliliter.^[12] Iohexol can given as intrathecal, intravascular, oral, rectal, intraarticular, or into the body cavity.^[12]