Omnipaque (Iohexol)

Omnipaque is an iodinated contrast agent used in diagnostic imaging to improve visualization of internal structures.

• X‑ray angiography: enhances the delineation of blood vessels for accurate assessment of vascular disease.
• Computed tomography (CT) scanning: provides high‑contrast detail of soft tissues, organs and vascular anatomy.
• Intravenous urography: improves visualization of the urinary collecting system for detection of obstruction or lesions.
• Myelography: offers contrast enhancement of the spinal canal during imaging of the vertebral column.
• Endovascular procedures: assists in real‑time imaging guidance during interventional radiology techniques.

• Iohexol is a non‑ionic, water‑soluble iodine compound that distributes rapidly throughout the extracellular fluid after intravascular injection. Its high atomic number absorbs X‑ray photons, creating a marked increase in radiodensity at the site of distribution, which produces enhanced contrast between vascular and tissue structures on radiographic and CT images.

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

Common Side Effects

• Warm sensation: transient feeling of heat or flushing.
• Nausea: mild, often self‑limiting gastrointestinal upset.
• Headache: mild to moderate discomfort.
• Metallic taste: brief alteration in oral sensation.
• Injection site discomfort: mild pain or irritation at the puncture site.

Serious or Rare Side Effects

• Anaphylactoid reaction: sudden onset of hives, bronchospasm or hypotension.
• Renal impairment: acute kidney injury, especially in patients with pre‑existing renal disease.
• Cardiovascular collapse: severe hypotension or arrhythmia.
• Seizures: rare neurologic events following rapid administration.
• Pulmonary edema: fluid accumulation in the lungs.
• Death: extremely rare but reported in severe hypersensitivity cases.

When using Omnipaque, clinicians should assess patient risk factors and follow recommended safety measures.

• Renal function assessment: evaluate baseline creatinine and eGFR before administration.
• Allergy history: screen for prior reactions to iodinated contrast or related agents.
• Hydration status: ensure adequate fluid intake before and after the procedure to reduce nephrotoxicity risk.
• Thyroid function: consider monitoring in patients with hyperthyroidism or thyroid nodules.
• Concomitant nephrotoxic drugs: avoid or adjust dosing of agents such as aminoglycosides or NSAIDs.
• Store at ambient temperature: keep in original packaging, protect from light and moisture.

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

Major Interactions (Avoid)

• Aminoglycoside antibiotics: increase risk of contrast‑induced nephropathy.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs): potentiate renal impairment when combined with iodinated contrast.

Moderate Interactions (Monitor Closely)

• Metformin: may accumulate if renal function declines; temporary discontinuation is often recommended.
• Beta‑blockers: can mask early signs of anaphylactoid reactions.
• Diuretics: may exacerbate fluid shifts and affect contrast clearance.
• ACE inhibitors/ARBs: influence renal hemodynamics and may increase nephrotoxic risk.
• Thyroid hormones: excess iodine load can alter thyroid hormone synthesis.