Iohexol
Also known as: Omnipaque
> **What is Iohexol?** Iohexol is a specialized medical dye (contrast agent) used to help veterinarians see your pet's internal organs more clearly on X-rays or CT scans. It is also used as a highly accurate test to measure how well your pet's kidneys are working. * **Safety**: This is a modern, "low-osmolar" contrast agent, meaning it is much gentler on the body and causes far fewer side effects than older dyes. * **What to Expect**: If used for imaging, it may be given by mouth, injected into a vein, or placed into a specific body cavity. If used for kidney testing, it is injected into a vein, and a few blood samples are drawn over the next several hours to see how fast the kidneys clear it from the blood. * **Side Effects**: Reactions are extremely rare in pets. However, watch for any signs of an allergic reaction (facial swelling, hives, difficulty breathing) or extreme lethargy, and contact your veterinarian immediately if these occur.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- Estimate GFR (single sample method)
- Contrast agent for suspected GI perforation
- Contrast agent (GI abnormalities, transit time)
- Estimate GFR (2-4 sample method)
- Estimate GFR (single sample method)
- Contrast agent for suspected GI perforation
How it is given
Possible side effects
- Hypersensitivity reactions (rare)
- Nephrotoxicity (slight risk)
- Pain or heat sensation at injection site (less common than with ionic agents)
Cautions & contraindications
- Prior hypersensitivity reaction to iohexol or iodine-containing products
- > **Hypersensitivity**: Always monitor for signs of anaphylaxis or allergic reactions, even though they are rare in veterinary patients. * **Nephrotoxicity**: While the risk is low, use with caution in patients with pre-existing severe renal impairment or dehydration; ensure adequate hydration prior to intravascular administration. * **Pregnancy**: FDA Category B. Animal studies have not demonstrated fetal risk, but use in late pregnancy carries potential theoretical risk to fetal thyroid function. * **Laboratory Interference**: Prior use of iohexol can reduce the iodine-binding capacity of thyroid tissue for up to 2 weeks, interfering with iodine-dependent thyroid function tests.
Drug interactions
- Drugs that prolong QTc interval (e.g., amiodarone, cisapride, procainamide, quinidine, sotalol, dolasetron, moxifloxacin): May cause additive prolongation of the QTc interval, though iohexol causes less prolongation than diatrizoate.
- Iodine Isotopes: May alter binding to thyroid tissue for up to two weeks, affecting certain thyroid treatments or scans.
- Phenothiazines: May increase the risk for lowering the seizure threshold, especially when iohexol is used intrathecally.
Frequently asked questions
What is Iohexol used for in pets?
> **What is Iohexol?** Iohexol is a specialized medical dye (contrast agent) used to help veterinarians see your pet's internal organs more clearly on X-rays or CT scans. It is also used as a highly accurate test to measure how well your pet's kidneys are working. * **Safety**: This is a modern, "low-osmolar" contrast agent, meaning it is much gentler on the body and causes far fewer side effects than older dyes. * **What to Expect**: If used for imaging, it may be given by mouth, injected into a vein, or placed into a specific body cavity. If used for kidney testing, it is injected into a vein, and a few blood samples are drawn over the next several hours to see how fast the kidneys clear it from the blood. * **Side Effects**: Reactions are extremely rare in pets. However, watch for any signs of an allergic reaction (facial swelling, hives, difficulty breathing) or extreme lethargy, and contact your veterinarian immediately if these occur.
Is Iohexol safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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