Omnipaque Injection

140   180   240   300   350

Section I Intrathecal

Section II Intravascular

Section III Oral/Body Cavity Use

Iohexol,N,N´ - Bis(2,3-dihydroxypropyl)-5-[N-(2,3-dihydroxypropyl)-acetamido]-2,4,6-triiodo-isophthalamide, is a nonionic, water-soluble radiographic contrast medium with a molecular weight of 821.14 (iodine content 46.36%). In aqueous solution each triiodinated molecule remains undissociated.

The chemical structure is:

OMNIPAQUE is provided as a sterile, pyrogen-free, colorless to pale-yellow solution, in the following iodine concentrations: 140, 180, 240, 300, and 350 mgI/mL. OMNIPAQUE 140 contains 302 mg of iohexol equivalent to 140 mg of organic iodine per mL; OMNIPAQUE 180 contains 388 mg of iohexol equivalent to 180 mg of organic iodine per mL; OMNIPAQUE 240 contains 518 mg of iohexol equivalent to 240 mg of organic iodine per mL; OMNIPAQUE 300 contains 647 mg of iohexol equivalent to 300 mg of organic iodine per mL; and OMNIPAQUE 350 contains 755 mg of iohexol equivalent to 350 mg of organic iodine per mL. Each milliliter of iohexol solution contains 1.21 mg tromethamine and 0.1 mg edetate calcium disodium with the pH adjusted between 6.8 and 7.7 with hydrochloric acid or sodium hydroxide. All solutions are sterilized by autoclaving and contain no preservatives. Unused portions must be discarded. Iohexol solution is sensitive to light and therefore should be protected from exposure.

The available concentrations have the following physical properties:

OMNIPAQUE 140, OMNIPAQUE 180, OMNIPAQUE 240, OMNIPAQUE 300, and OMNIPAQUE 350 have osmolalities from approximately 1.1 to 3.0 times that of plasma (285 mOsm/kg water) or cerebrospinal fluid (301 mOsm/kg water) as shown in the above table and are hypertonic under conditions of use.

Suggestions for Usual Patient Management

Good patient management should be exercised at all times to minimize the potential for procedurally related complications.

Preprocedure

• Discontinuance of neuroleptic drugs (including phenothiazines, eg, chlorpromazine, prochlorperazine, and promethazine) at least 48 hours beforehand should be considered.
• Maintain normal diet up to 2 hours before procedure.
• Ensure hydration-fluids up to procedure.

During Procedure

• Use minimum dose and concentration required for satisfactory contrast (see DOSAGE AND ADMINISTRATION).
• In all positioning techniques keep the patient's head elevated above highest level of spine.
• Do not lower head of table more than 15° in moving contrast medium cranially.
• In patients with excessive lordosis, consider lateral position for injection and movement of the medium cephalad.
• Inject slowly (over 1 to 2 minutes) to avoid excessive mixing.
• To maintain as a bolus, move medium to distal area very slowly. Use fluoroscopic monitoring.
• Avoid intracranial entry of a bolus.
• Avoid early and high cephalad dispersion of the medium.
• Avoid abrupt or active patient movement to minimize excessive mixing of medium with CSF. Instruct patient to remain passive. Move patient slowly and only as necessary.

Postprocedure

• Raise head of stretcher to at least 30° before moving patient onto it.
• Movement onto and off the stretcher should be done slowly with the patient completely passive, maintaining head-up position.
• Before moving patient onto bed, raise head of bed 30° to 45°.
• Advise patient to remain still in bed, in a sitting or semisitting position, especially in the first few hours.
• Maintain close observation for at least 12 hours after myelogram.
• Obtain visitors' cooperation in keeping the patient quiet and in head-up position, especially in first few hours.
• Encourage oral fluids. Diet as tolerated.
• If nausea or vomiting occurs, do not use phenothiazine antinauseants. Persistent nausea and vomiting will result in dehydration. Therefore, prompt consideration of replacement by intravenous fluids is recommended.

Alternative Postprocedure Method

• Recent evidence with nonionic, water-soluble contrast media suggests that maintaining the patient postmyelography in an upright position (via wheelchair or ambulation) may help minimize adverse effects. The upright position may help to delay upward dispersion of the medium and to maximize the spinal arachnoid absorption.

OMNIPAQUE 350 is indicated in adults for angiocardiography (ventriculography, selective coronary arteriography), aortography including studies of the aortic root, aortic arch, ascending aorta, abdominal aorta and its branches, contrast enhancement for computed tomographic head and body imaging, intravenous digital subtraction angiography of the head, neck, abdominal, renal and peripheral vessels, peripheral arteriography, and excretory urography.

OMNIPAQUE 350 is indicated in children for angiocardiography (ventriculography, pulmonary arteriography, and venography; studies of the collateral arteries and aortography, including the aortic root, aortic arch, ascending and descending aorta).

OMNIPAQUE 300 is indicated in adults for aortography including studies of the aortic arch, abdominal aorta and its branches, contrast enhancement for computed tomographic head and body imaging, cerebral arteriography, peripheral venography (phlebography), and excretory urography.

OMNIPAQUE 300 is indicated in children for angiocardiography (ventriculography), excretory urography, and contrast enhancement for computed tomographic head imaging.

OMNIPAQUE 240 is indicated in adults for contrast enhancement for computed tomographic head imaging and peripheral venography (phlebography).

OMNIPAQUE 140 is indicated in adults for intra-arterial digital subtraction angiography of the head, neck, abdominal, renal and peripheral vessels.

OMNIPAQUE 240 is indicated in children for contrast enhancement for computed tomographic head imaging.

OMNIPAQUE should not be administered to patients with a known hypersensitivity to iohexol.

See SECTION II, DOSAGE AND ADMINISTRATIONGeneral.