Omnipaque Injection (Iohexol)

Omnipaque Injection is a non‑ionic contrast agent used in radiographic procedures that require enhanced imaging of body structures.

• Angiography: Improves visualisation of blood vessels during cerebral, coronary and peripheral studies.
• Computed Tomography (CT): Provides high‑contrast images of abdominal, thoracic and head scans.
• Intravenous uro‑urography: Enhances delineation of the urinary tract during excretory phase imaging.
• Myelography: Facilitates clear imaging of the spinal canal and nerve roots.
• Endovascular interventions: Supports real‑time imaging guidance during minimally‑invasive therapeutic procedures.

• Iohexol is a water‑soluble, iodine‑based compound that absorbs X‑ray photons, increasing radiodensity of blood and extracellular fluids. After intravenous administration, it distributes rapidly throughout the vascular and interstitial compartments, providing temporary contrast enhancement that delineates anatomical structures during imaging. Its non‑ionic structure reduces protein binding and osmotic effects compared with older agents, allowing clearer images with a lower incidence of adverse reactions.

Adverse reactions to Omnipaque Injection can range from mild to severe and should be monitored during and after administration.

Common Side Effects

• Warm sensation or flushing: Transient feeling of heat in the face or neck.
• Nausea or vomiting: Mild gastrointestinal upset following injection.
• Headache: Temporary headache that resolves without intervention.
• Metallic taste: Brief metallic sensation in the mouth.
• Mild urination urgency: Temporary increase in urinary frequency.

Serious or Rare Side Effects

• Anaphylactoid reaction: Rapid onset of hives, bronchospasm, or hypotension.
• Renal impairment: Acute kidney injury, especially in patients with pre‑existing renal disease.
• Severe hypotension: Sudden drop in blood pressure requiring medical management.
• Cardiac arrhythmias: Irregular heart rhythms observed during or after injection.
• Pulmonary edema: Fluid accumulation in the lungs presenting with breathlessness.

Before using Omnipaque Injection, clinicians should assess patient history and monitor for potential adverse events.

• Renal function assessment: Evaluate baseline creatinine and eGFR, especially in at‑risk patients.
• Allergy history: Verify prior reactions to iodine‑based contrast or other contrast media.
• Hydration status: Ensure adequate fluid intake before and after the procedure to support renal clearance.
• Concomitant nephrotoxic drugs: Review and possibly suspend medications such as NSAIDs or aminoglycosides.
• Thyroid function: Consider testing in patients with known thyroid disorders.
• Store at 2-8°C: Keep refrigerated, protect from light, do not freeze or shake the vial.

Omnipaque Injection may interact with other agents that affect renal function or cause hypersensitivity.

Major Interactions (Avoid)

• Aminoglycoside antibiotics: Increased risk of nephrotoxicity when combined with iodinated contrast.
• Loop diuretics: May exacerbate renal impairment and fluid‑electrolyte disturbances.

Moderate Interactions (Monitor Closely)

• Metformin: Potential for lactic acidosis in patients with reduced renal clearance; withhold temporarily after contrast exposure.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs): May heighten risk of contrast‑induced nephropathy.
• ACE inhibitors/ARBs: Can affect renal haemodynamics; monitor kidney function closely.