Iopamidol

Iopamidol is a nonionic iodinated contrast agent used to enhance the visibility of vascular structures and organs during diagnostic imaging procedures. Approved and clinically accepted indications include:

• Computed Tomography (CT) Scans: Enhancement of soft tissues and blood vessels in brain, chest, abdomen, pelvis, and other areas.
• Angiography: Visualization of arteries and veins including cerebral, coronary, peripheral, and aortic vessels.
• Intravenous Urography (IVP): Imaging of kidneys, ureters, and bladder.
• Myelography: Imaging of the spinal cord and nerve roots.
• Arthrography: Contrast-enhanced imaging of joint spaces.
• Gastrointestinal Studies: Oral or rectal administration for imaging of the esophagus, stomach, and intestines.

• Adults:
• Dose depends on imaging type and patient weight.
• Typical intravenous doses: 50 to 150 mL of Iopamidol solution (e.g., 300 mg iodine/mL) for CT and angiography.
• Urography: 30 to 100 mL intravenously.
• Myelography and arthrography: Lower doses per procedural protocols.
• Pediatrics:
• Dose calculated on body weight: approximately 1.5–2 mL/kg, adjusted for the procedure.
• Careful dose calculation to minimize iodine load.
• Elderly:
• No routine dose adjustment, but renal function assessment is important.
• Special Populations:
• Renal impairment: Use the lowest effective dose; ensure hydration.
• Hepatic impairment: No dose adjustments needed.
• Route of Administration:
• Intravenous (IV), intra-arterial, intrathecal, oral, or rectal depending on procedure.
• Frequency:
• Single administration per diagnostic procedure.

Iopamidol contains iodine atoms that absorb X-rays effectively. When administered, it distributes in the extracellular fluid and highlights vascular structures and organs by increasing contrast on X-ray and CT images. The high atomic number of iodine attenuates X-rays, allowing enhanced visualization of anatomical detail and pathological changes during imaging.

• Absorption: Not absorbed systemically when administered orally or rectally; IV/intra-arterial administration results in immediate systemic availability.
• Distribution: Rapid extracellular distribution; does not bind significantly to plasma proteins or tissues.
• Metabolism: Not metabolized; excreted unchanged.
• Elimination: Primarily renal via glomerular filtration.
• Half-life: Approximately 2 hours in normal renal function.
• Onset: Immediate contrast effect upon administration.
• Excretion: >90% eliminated in urine within 24 hours.

• Pregnancy: Category B — animal studies show no harm, but adequate human studies are lacking. Use only if benefits justify potential risks.
• Lactation: Excreted in breast milk in small amounts. Minimal infant absorption expected; use caution.
• Recommendation: Avoid unless necessary; discuss risks and benefits with patient.

• Radiographic contrast agent
• Nonionic, low-osmolality iodinated contrast media

• Hypersensitivity to Iopamidol or other iodinated contrast agents
• Severe uncontrolled asthma or history of severe contrast reactions
• Acute severe renal failure without dialysis options
• Decompensated congestive heart failure where fluid overload is a risk
• Intrathecal use contraindicated in elevated intracranial pressure or CNS infection

• Increased risk of nephrotoxicity in patients with renal impairment, diabetes, dehydration, or multiple myeloma.
• Risk of anaphylactic reactions; emergency treatment facilities must be available.
• Use caution in thyroid disease due to iodine content.
• Temporarily discontinue metformin to reduce risk of lactic acidosis if renal function is impaired.
• Monitor renal function before and after administration in at-risk patients.
• Adequate hydration recommended to reduce nephrotoxicity risk.
• Intrathecal administration may cause seizures or neurotoxicity; follow strict procedural protocols.

• Common: Nausea, vomiting, warmth or flushing during injection, headache, dizziness, mild injection site discomfort.
• Serious (rare): Anaphylaxis, bronchospasm, hypotension, contrast-induced nephropathy, seizures (especially intrathecal use), arrhythmias, tissue injury from extravasation.
• Side effects typically occur within minutes but delayed reactions are possible.

• Metformin: Risk of lactic acidosis; withhold metformin 48 hours post-procedure if renal impairment is present.
• Nephrotoxic drugs: Concomitant use with NSAIDs, aminoglycosides, or cyclosporine may increase renal risk.
• Thyroid medications: Iodine load may alter thyroid function.
• Diuretics: May worsen dehydration, increasing nephrotoxicity risk.
• No significant CYP450 enzyme involvement.

• Emphasis on minimizing iodine dose, especially in renal impairment.
• Recommendations for pre- and post-procedure hydration to protect kidneys.
• Updated protocols for metformin management around contrast administration.
• Enhanced screening and premedication for patients with prior contrast reactions.
• Research ongoing into lower-osmolality agents to reduce adverse events.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from freezing and excessive heat.
• Keep container tightly closed and away from light.
• Inspect for discoloration or particulates before use.
• Ready-to-use; no reconstitution needed.