Iohexol

Iohexol is a nonionic, water-soluble radiographic contrast medium. It blocks X-rays as they pass through the body, thereby allowing body structures not containing iodine to be visualized. The degree of opacity produced by Iohexol is directly proportional to the total amount of the iodinated contrast agent in the path of the X-rays.

• Angiocardiography
• Aortography
• Intravenous digital subtraction angiography
• Peripheral arteriography
• Excretory urography
• CT scanning

Adult Dose (Intravascular):

• Ventriculography: 40 mL (range 30-60 mL); may repeat as needed, not to exceed 250 mL
• Selective Coronary Arteriography: 5 mL (range 3-14 mL per injection)
• Aortic Root and Arch Study: 50 mL (range 20-75 mL)
• Pulmonary Angiography: 1 mL/kg
• CT Scanning (Head): 70-150 mL (Iohexol 300); 80 mL (Iohexol 350)
• CT Scanning (Body): 50-200 mL (Iohexol 300); 60-100 mL (Iohexol 350)
• Excretory Urography: 200-350 mgI/kg body weight

Child Dose (Intravascular):

• Angiocardiography: 1.25-1.75 mL/kg; not to exceed 5-6 mL/kg or 250-291 mL
• CT Scanning: 1-2 mL/kg

Common Side Effects:

• Nausea (2%)
• Vomiting (0.7%)
• Diarrhea

Cardiovascular: Arrhythmias (PVCs, PACs), angina/chest pain, hypotension, cardiac failure, asystole, bradycardia, tachycardia

Nervous System: Vertigo, pain, vision abnormalities, headache, taste perversion, convulsion, paresthesia, somnolence, syncope

Skin: Urticaria, purpura, pruritus

Precautions:

• It is not known whether Iohexol alters ability to drive; do not drive if you experience symptoms affecting concentration and reaction
• Emergency facilities should be available for 30-60 minutes after parenteral administration
• Preparatory dehydration is dangerous and may contribute to acute renal failure; patients should be well hydrated
• Caution in patients with history of allergies or hypersensitivity
• Caution in patients with congestive heart failure
• Avoid angiography in patients with homocystinuria

Contraindications:

• Known hypersensitivity to iohexol
• Intrathecal: Myelography where bacteremia is likely; concurrent use with corticosteroids; repeat myelography in technical failure

Drug Interactions:

• Iodine-binding capacity of thyroid tissue may be reduced for up to 2 weeks after contrast medium administration
• Many radiopaque contrast agents are incompatible with some antihistamines and other drugs

Food Interactions: It is unsafe to consume alcohol with Iohexol.

Use in Pregnancy: Category B; no adequate studies in pregnant women; use only if potential benefit justifies potential risk to fetus.

Use in Lactation: It is not known to what extent iohexol is excreted in human milk; bottle feedings may be substituted for breast feedings for 24 hours following administration.

Renal Impairment: Caution in kidney disease; dose adjustment may be needed; risk of acute renal failure in diabetic patients and patients with pre-existing renal disease.

Hepatic Impairment: Caution in liver disease; dose adjustment may be needed.

Overdose: Adverse effects are life-threatening and affect mainly pulmonary and cardiovascular systems; symptoms include cyanosis, bradycardia, acidosis, pulmonary hemorrhage, convulsions, coma, cardiac arrest; treatment is supportive and symptomatic.