Iohexol

Iohexol, sold under the trade name Omnipaque among others, is a contrast agent used for X-ray imaging.^[4] This includes when visualizing arteries, veins, ventricles of the brain, the urinary system, and joints, as well as during computed tomography (CT scan).^[4] It is given by mouth, injection into a vein, or into a body cavity.^[5]

Iohexol

Clinical data
Trade names	Omnipaque, 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: WARNING[3]Rx-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.^[4] Less commonly allergic reactions or seizures may occur.^[4] Allergies to povidone-iodine or shellfish do not affect the risk of side effects more than other allergies.^[6] Use in the later part of pregnancy may cause hypothyroidism in the baby.^[7] Iohexol is an iodinated non-ionic radiocontrast agent.^[4] It is in the low osmolar family.^[8]

Iohexol was approved for medical use in 1985.^[9] It is on the World Health Organization's List of Essential Medicines.^[10][5]

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.^[11] 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.^[12]

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%).^[13]

Society and culture

Naming

It is sold under the brand names Omnipaque.^[14] It is also sold as a density gradient medium under the names Accudenz, Histodenz, and Nycodenz.^[15][16]

Available forms

It is available in various concentrations, from 140^[13] to 350^[17] milligrams of iodine per milliliter.^[13] Iohexol can given as intrathecal, intravascular, oral, rectal, intraarticular, or into the body cavity.^[13]

References

1. "Product monograph brand safety updates". Health Canada. February 2024. Retrieved 24 March 2024.
2. "Regulatory Decision Summary for Omnipaque". Drug and Health Products Portal. 29 December 2023. Retrieved 2 April 2024.
3. "FDA-sourced list of all drugs with black box warnings (Use Download Full Results and View Query links.)". nctr-crs.fda.gov. FDA. Retrieved 22 October 2023.
4. World Health Organization (2009). Stuart MC, Kouimtzi M, Hill SR (eds.). WHO Model Formulary 2008. World Health Organization. pp. 317–8. hdl:10665/44053. ISBN 9789241547659.
5. Hamilton R (2015). Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition. Jones & Bartlett Learning. p. 171. ISBN 9781284057560.
6. ACR Manual on Contrast Media v10.3. 2017 (PDF). American College of Radiology. 2017. p. 6. ISBN 9781559030120. Archived (PDF) from the original on 1 January 2018. Retrieved 1 January 2018.
7. Briggs GG, Freeman RK, Yaffe SJ (2011). Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk. Lippincott Williams & Wilkins. p. 761. ISBN 9781608317080. Archived from the original on 1 January 2017.
8. Sutton D, Young JW (2012). A Short Textbook of Clinical Imaging. Springer Science & Business Media. p. 235. ISBN 9781447117551. Archived from the original on 1 January 2017.
9. Broe ME, Porter GA, Bennett WM, Verpooten GA (2013). Clinical Nephrotoxins: Renal Injury from Drugs and Chemicals. Springer Science & Business Media. p. 325. ISBN 9789401590884. Archived from the original on 1 January 2017.
10. World Health Organization (2019). World Health Organization model list of essential medicines: 21st list 2019. Geneva: World Health Organization. hdl:10665/325771. WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
11. GE Healthcare (May 2006). "Omnipaque (Iohexol) injection. Product label". DailyMed. U.S. National Library of Medicine. Retrieved 28 March 2007.
12. Amersham Health (April 2006). "Hypaque (Diatrizoate Meglumine and Diatrizoate Sodium) injection, solution. Product label". DailyMed. U.S. National Library of Medicine. Archived from the original on 23 May 2011. Retrieved 29 March 2007.
13. "Highlights of prescribing information for Omnipaque" (PDF). US Food and Drug Administration. Archived from the original (PDF) on 11 July 2022. Retrieved 13 December 2022.
14. "Omnipaque" (PDF). Ireland: Health Products Regulatory Authority. January 2018. Retrieved 31 July 2020.
15. "HistoDenz" (PDF). Product information sheet. Sigma-Aldrich. D2158. Archived from the original (PDF) on 20 November 2015. Retrieved 19 November 2015.
16. "Nycodenz®: A universal density gradient medium" (PDF). Axis-Shield Density Gradient Media. Archived from the original (PDF) on 26 February 2015. Retrieved 19 November 2015.
17. Haberfeld H, ed. (2020). Austria-Codex (in German). Vienna: Österreichischer Apothekerverlag. Omnipaque 350 mg J/ml Infusionsflasche.