2.1  Recommended Dosing

For oral use only[see Warnings and Precautions (5.1)]

Refer to Table 1 for dosing information.

Table 1 Dosing Guidelines for Oraltag

The variables of patient age, weight, or medical condition, may require adjustment of the concentration and/or volume of solution to be prepared for administration. If it is anticipated that the patient will have difficulty in consuming the required volume, a higher concentration of solution (up to 21 mgI per mL) can be prepared and a smaller volume administered (see Table 2).

Table 2 Preparation of Higher Concentrations of Oraltag at Lower Volumes

2.2  Preparation and Administration Instructions

• Reconstitute Oraltag, supplied as a powder in a single use bottle, with water or other beverages just before its use
• Do not mix other pharmaceuticals with Oraltag
• Use the 5 fill lines premolded and labeled on the bottle to determine the volume for the 5 target concentrations (9, 12, 15, 18, and 21 mgI/mL)
• Administer Oraltag 20 to 60 minutes before image acquisition
• Protect prepared solution from strong daylight and direct exposure to sunlight
• Discard any unused portions

5.1  Risks Associated with Inadvertent Parenteral Administration

Oraltag is not a sterile product and is not suitable for a parenteral route of administration. Serious adverse reactions such as sepsis can occur if administered parenterally. Do not administer Oraltag parenterally.

5.2  Hypersensitivity Reactions

Administration of Oraltag can cause life-threatening hypersensitivity reactions including anaphylaxis [see Contraindications (4)] . Patients at increased risk include those with a previous reaction to an iodinated contrast agent and allergic disorders (i.e., bronchial asthma, allergic rhinitis, and food allergies). Emergency resuscitation equipment and trained personnel should be available.

5.3  Alteration of Thyroid Function Tests

Iodinated contrast agents may alter the results of thyroid function tests which depend on iodine estimation, e.g., radioactive iodine uptake test. Therefore, such testing, if indicated, should be performed prior to the administration of this preparation.

6.1  Clinical Trials Experience

In studies involving 44 adult and 69 pediatric patients who received oral and intravenous iohexol for CT examinations of the abdomen, two reports of vomiting (2%) were noted.

6.2  Postmarketing Experience

Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

The following adverse reactions have been reported following oral administration of the dilute, hypotonic solutions of iohexol (9 mgI/mL to 21 mgI/mL):

• Gastrointestinal: nausea, diarrhea

8.1 Pregnancy

Risk Summary

There are no human data on risks associated with the use of Oraltag during pregnancy. The background risk in the U.S. general population of major birth defects is 2% to 4% and risk of miscarriage is 15% to 20% of clinically recognized pregnancies. In animal reproduction studies, no evidence of fetal harm was observed with intravenous administration of iohexol to rats and rabbits at doses up to 100 times the maximum recommended human intravenous dose.

8.2 Lactation

Risk Summary

Iohexol administered intravenously is present in human milk at concentrations approximately 0.5% of the maternal dose; however, it is not known to what extent iohexol administered orally is present in human milk. Iodinated contrast is poorly excreted into human milk and is poorly absorbed by the gastrointestinal tract of a breastfed infant. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for Oraltag and any potential adverse effects on the breastfed infant from Oraltag.

Clinical Considerations

Interruption of breastfeeding after exposure to iodinated contrast media is not necessary because the potential exposure of the breastfed infant to iodine is small. However, a lactating woman may consider interrupting breastfeeding and pumping and discarding breast milk for 10 hours (approximately 5 half-lives) after Oraltag administration in order to minimize potential drug exposure to a breastfed infant.

8.4 Pediatric Use

The safety and effectiveness of oral iohexol have been established in pediatric patients.

8.5 Geriatric Use

In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

12.1  Mechanism of Action

Iohexol enhances imaging due to its high iodine content attenuating the beam of X-rays during CT examinations. Different tissues within the body attenuate X-rays to different degrees, and oral administration of iohexol allows for enhanced visualization due to the iodine present in bowel loops.

12.3 Pharmacokinetics

Orally administered iohexol is very poorly absorbed from the normal gastrointestinal tract. Only 0.1 to 0.5% of the oral dose is excreted by the kidneys. This amount may increase in the presence of bowel perforation, bowel obstruction, or severe inflammatory bowel disease.

Iohexol displays a low affinity for serum or plasma proteins and is poorly bound to serum albumin. No significant metabolism, deiodination or biotransformation occurs.

13.1  Carcinogenesis, Mutagenesis, Impairment of Fertility

No long-term animal studies have been performed to evaluate carcinogenic potential or mutagenesis.

In animal reproduction studies, no evidence of impaired fertility was observed with intravenous administration of iohexol to rats and rabbits at doses up to 100 times the maximum recommended human intravenous dose.