Indigo Carmine

• Indigo Carmine is used in diagnostic procedures that assess renal performance and urinary‑tract anatomy.
• Renal function testing: enables quantitative assessment of glomerular filtration rate and kidney excretory capacity.
• Urinary tract imaging: provides clear visualisation of ureters, bladder and renal collecting systems during radiographic studies.
• Intraoperative dye use: assists surgeons in identifying urinary structures during operative procedures.
• Renal perfusion assessment: serves as a tracer to evaluate renal blood flow during angiographic examinations.

• Indigo Carmine acts as an inert visual tracer that is filtered by the glomeruli and excreted unchanged in the urine. After intravenous administration, the dye circulates rapidly, reaches the kidneys, and appears in the urinary tract, allowing real‑time imaging of renal filtration and urinary anatomy without interacting with metabolic pathways.

Adverse reactions may occur following intravenous administration of Indigo Carmine.

Common Side Effects

• Transient hypotension: brief drop in blood pressure after injection.
• Nausea or vomiting: mild gastrointestinal upset.
• Flushing or skin discoloration: temporary reddish hue of skin.
• Headache: mild to moderate intensity.
• Mild allergic reactions: urticaria or itching.
• Dizziness: sensation of light‑headedness.

Serious or Rare Side Effects

• Anaphylaxis: severe, potentially life‑threatening allergic response.
• Methemoglobinemia: elevated methemoglobin levels causing cyanosis.
• Severe hypotension: prolonged low blood pressure requiring intervention.
• Cardiac arrhythmia: irregular heart rhythm associated with rapid infusion.
• Renal impairment: unexpected decline in kidney function.
• Pulmonary edema: fluid accumulation in lungs in susceptible individuals.

• When using Indigo Carmine, clinicians should observe several safety measures.
• Pregnancy: use only if clearly needed, as safety data are limited.
• Allergy assessment: verify no known hypersensitivity to indigo dyes or related compounds.
• Renal impairment: monitor kidney function closely, especially in patients with pre‑existing disease.
• Concomitant vasodilators: anticipate additive hypotensive effects and adjust infusion rate.
• Intravenous administration: ensure proper dilution and slow injection to minimise cardiovascular reactions.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Indigo Carmine may interact with other agents that influence cardiovascular tone or allergic risk.

Major Interactions (Avoid)

• Concurrent vasodilators (e.g., nitroglycerin): may cause severe hypotension.
• Other diagnostic dyes: increase risk of cumulative allergic reactions.
• Monoamine oxidase inhibitors: potential for unpredictable hemodynamic changes.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may mask tachycardia that signals hypotension.
• Antihistamines: could blunt early signs of an allergic response.
• Diuretics: may alter renal excretion and affect dye clearance.