AHFS Class:

36:68 Roentgenographic and Other Imaging Agents

Generic Name

• Iohexol (CAS Registry Number: 66108-95-0)

Iohexol is available as an injection solution in concentrations of 140, 180, 240, 300, or 350 mg/mL of organically bound iodine (mg I/mL) equivalent to 302 (30.2%), 388 (38.8%), 518 (51.8%), 647 (64.7%), or 755 (75.5%) mg/mL, respectively, of iohexol in vial or bottle sizes ranging from 10 to 200 mL; not all concentrations are available in all sizes.²⁵²³ The 300- and 350-mg I/mL concentrations also are available in a 500-mL pharmacy bulk package intended for dispensing multiple single doses using a suitable transfer device.²⁷⁴³ Also present in each mL are tromethamine 1.21 mg, edetate calcium disodium 0.1 mg, and hydrochloric acid or sodium hydroxide to adjust the pH.²⁵²³ Table 1 presents the characteristics of iohexol products.

Table 1. Iohexol Product Characteristics²⁵²³

pH

6.8 to 7.7.²⁵²³

Trade Name(s)

Omnipaque

Depending on the concentration, iohexol may be administered intravenously, intra-arterially, or intrathecally, at either body or room temperature.²⁵²³ Extravasation should be avoided.²⁵²³ Iohexol 140, 240, 300 and 350 mg I/mL are indicated for intravascular (intravenous or intra-arterial) administration.²⁵²³ Iohexol 180, 240, and 300 mg I/mL are indicated for intrathecal administration; the 140- and 350-mg I/mL concentrations are contraindicated for intrathecal use.²⁵²³ Intrathecal injection should be made slowly over 1 to 2 minutes.²⁵²³

Iohexol may be used with an automated contrast injection system or contrast media management system cleared for use with the product.²⁵²³ Consult specific device labeling for additional information.²⁵²³

Iohexol is a colorless to pale yellow solution.²⁵³² Intact containers should be stored at controlled room temperature and protected from light and from freezing.²⁵²³; ²⁷⁴³ Discard the product if inadvertently frozen because of possible damage to closure integrity.²⁵²³ Intact containers may be stored in a contrast media warmer at 36 to 38°C for up to 1 month.²⁵²³; ²⁷⁴³

For some indications, iohexol injection may be diluted with sterile water for injection to a concentration of 50 to 100 mg I/mL.²⁵²³ Diluted solutions should be used immediately and any unused portion discarded after the procedure.²⁵²³

If used with an automated contrast management system, the maximum use time is 4 hours after initial puncture.²⁵²³

Withdrawal of contents from pharmacy bulk packages should be completed within of 8 hours of initial closure entry.²⁷⁴³ After closure entry, the temperature of the container should not exceed 37°C.²⁷⁴³

Drugs in Syringe Compatibility

Y-Site Injection Compatibility (1:1 Mixture)

For a list of references cited in the text of this monograph, search the monograph titled References.

ASHP^® Injectable Drug Information^TM. Selected Revisions April 7, 2022. © Copyright, 2025. American Society of Health-System Pharmacists^®, 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.