OMNIPAQUE 300 MG/ML

Indications

• Myelography
• Arthrography
• Nephroangiography
• Arteriography
• Computed tomography (CT) scans with contrast

Dosage

Children: Refer to BNF for Children for specific dosing recommendations based on age, weight, and the type of procedure.

Adults: Refer to BNF for specific dosing guidelines based on the type of procedure and patient condition.

Mechanism of action

Organic iodine compounds block x-rays as they pass through the body, thereby allowing body structures containing iodine to be delineated in contrast to those structures that do not contain iodine. The degree of opacity produced by these compounds is directly proportional to the total amount of the iodinated contrast agent in the path of the x-rays. After intrathecal administration, diffusion of iohexol in the CSF allows visualization of the subarachnoid spaces of the head and spinal canal. After intravascular administration, iohexol makes opaque those vessels in its path of flow, allowing visualization of the internal structures until significant hemodilution occurs.

Pharmacodynamics

Iohexol is an effective non-ionic, water-soluble contrast agent used in various radiographic procedures such as myelography, arthrography, nephroangiography, and arteriography. Its low systemic toxicity is due to both low chemotoxicity and low osmolality, making it safer for patients compared to older contrast agents.

Pharmacokinetics

Iohexol is administered intravascularly or intrathecally, where it diffuses into the bloodstream or cerebrospinal fluid, respectively. It is excreted primarily through the kidneys; thus, renal function can affect its clearance. The half-life and distribution can vary based on the route of administration and the individual's physiological characteristics.

Contra-indications

• Known hypersensitivity to iohexol or any of its components
• Severe dehydration
• Severe renal impairment (eGFR <30 mL/min)

Adverse effects

• Nausea
• Vomiting
• Headache
• Dizziness
• Urticaria
• Anaphylactic reactions
• Renal impairment
• Extravasation

Interactions

• Other nephrotoxic agents may increase the risk of renal impairment when used with iohexol
• Metformin: there is a risk of lactic acidosis in patients with renal impairment after administration of iodinated contrast agents

Precautions

• Assess renal function prior to administration, especially in patients with pre-existing renal impairment
• Use caution in patients with a history of asthma or allergic reactions
• Ensure adequate hydration before and after the procedure to minimize the risk of nephrotoxicity
• Monitor for signs of anaphylaxis during and after administration

Pregnancy

Iohexol should only be used in pregnancy if the potential benefit justifies the potential risk to the fetus. It is classified as a Category B drug.

Breast-feeding

It is generally considered safe to use iohexol during breastfeeding, but it is advised to monitor the infant for any potential adverse effects.

Storage

Store at room temperature, between 15°C and 30°C. Protect from light. Do not freeze.

Formulations

• Iohexol injection (various concentrations available)

Mechanism of action

Organic iodine compounds block x-rays as they pass through the body, thereby allowing body structures containing iodine to be delineated in contrast to those structures that do not contain iodine. The degree of opacity produced by these compounds is directly proportional to the total amount (concentration and volume) of the iodinated contrast agent in the path of the x-rays. After intrathecal administration into the subarachnoid space, diffusion of iohexol in the CSF allows the visualization of the subarachnoid spaces of the head and spinal canal. After intravascular administration, iohexol makes opaque those vessels in its path of flow, allowing visualization of the internal structures until significant hemodilution occurs.

Pharmacodynamics

Iohexol is an effective non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiographic procedures. Its low systemic toxicity is the combined result of low chemotoxicity and low osmolality.