Omnipaque (Iohexol)

Omnipaque is a non‑ionic low‑osmolality contrast medium used in radiographic procedures that require enhanced vascular and tissue visualization.

• Angiography: Improves delineation of blood vessels for diagnostic and interventional procedures.
• Computed Tomography (CT): Provides high‑contrast enhancement of abdominal, thoracic, and cerebral structures.
• Intravenous urography: Facilitates clear imaging of the urinary collecting system.
• Myelography: Enhances visualization of the spinal canal and nerve roots.
• Contrast‑enhanced MRI (off‑label in some regions): Used experimentally to improve lesion conspicuity.

• Iohexol is a water‑soluble, iodine‑based compound that transiently increases the attenuation of X‑ray photons in the vascular and extracellular spaces. After intravenous administration, the iodine atoms absorb X‑ray energy, producing a temporary contrast between blood‑filled structures and surrounding tissues, which enables detailed radiographic imaging of anatomy and pathology.

Adverse reactions to Iohexol may range from mild to severe and are reported across patient populations.

Common Side Effects

• Warmth or flushing sensation at the injection site.
• Mild nausea or vomiting.
• Transient headache.
• Metallic taste in the mouth.
• Mild itching or urticaria.
• Temporary increase in serum creatinine.

Serious or Rare Side Effects

• Severe allergic reactions (anaphylaxis).
• Acute kidney injury, especially in patients with pre‑existing renal impairment.
• Cardiovascular collapse or hypotension.
• Pulmonary edema.
• Seizures.
• Fatal outcomes in rare cases of severe hypersensitivity.

When using Iohexol, clinicians should assess patient risk factors and follow appropriate monitoring protocols.

• Renal function assessment: Evaluate serum creatinine and eGFR before administration.
• Allergy history: Screen for prior reactions to iodine‑based contrast agents.
• Hydration status: Ensure adequate patient hydration to reduce nephrotoxic risk.
• Cardiovascular status: Monitor blood pressure and heart rate during injection.
• Concomitant nephrotoxic drugs: Use caution with NSAIDs, aminoglycosides, or chemotherapeutics.
• Store at ambient temperature: Keep vials in the original packaging, protect from light and moisture.

Iohexol may interact with other agents that affect renal function or hypersensitivity risk.

Major Interactions (Avoid)

• Concurrent high‑dose NSAIDs: Increases risk of contrast‑induced nephropathy.
• Aminoglycoside antibiotics: Potentiates renal toxicity when combined with contrast.

Moderate Interactions (Monitor Closely)

• Metformin: May require temporary discontinuation in patients with reduced renal clearance.
• Loop diuretics: Can exacerbate volume depletion and renal impairment.
• Beta‑blockers: May mask early signs of contrast‑induced hypertension.
• ACE inhibitors/ARBs: Monitor blood pressure and renal function closely.
• Radiopharmaceuticals: Coordinate timing to avoid overlapping imaging contrast effects.