Amidotrizoic Acid

BRAND NAMES

• Amidotrizoic acid: Amidotrizoic acid, also known as diatrizoic acid, is a pharmaceutical agent used as a radiocontrast medium to improve the visibility of internal structures during medical imaging.

• Gastrografin: Gastrografin is a brand name for a water-soluble, iodinated radiocontrast medium used for X-ray and computed tomography (CT) imaging of the gastrointestinal (GI) tract.

MECHANISM OF ACTION

Amidotrizoic acid functions as an X-ray contrast agent by absorbing X-rays more efficiently than surrounding tissues, thanks to its three iodine atoms. Once administered, it disperses throughout the body, and the iodine blocks X-rays in the areas it fills. This creates a clearer contrast on diagnostic images such as X-rays and CT scans, allowing internal structures to be more easily visualized.

PHARMACOKINETICS:

Absorption

Amidotrizoic acid is a radiocontrast agent used to improve the clarity of internal structures during medical imaging. Its effectiveness comes from the presence of iodine, which has a high atomic number and absorbs more X-rays than the surrounding tissues, thereby enhancing image contrast.

Distribution

After administration for medical imaging, amidotrizoic acid is distributed throughout the body and primarily eliminated through the kidneys. It can be given orally, intravenously, or rectally, and its relatively rapid excretion limits prolonged exposure within the body.

Metabolism

• Amidotrizoic acid is a stable, water-soluble contrast agent designed to pass through the body without being chemically altered by enzymes.

• Its mechanism of action relies on the absorption of X-rays by its high iodine content to create contrast in diagnostic images. If the compound were metabolized, its radiopaque properties could be compromised.

Elimination

• It is rapidly distributed throughout the circulatory system.

• The kidneys' glomeruli filter the substance from the blood.

• It is then excreted from the body in the urine, mostly in its original, unchanged form.

• For oral administration, such as for gastrointestinal imaging, the drug is not absorbed significantly by the digestive tract and is eliminated via the feces.

• The rate of elimination can vary depending on the patient's renal function, the type of diatrizoic acid used (e.g., ionic versus non-ionic), and the specific imaging technique.

PHARMACODYNAMICS

Amidotrizoic acid, also called diatrizoate, is a radiopaque contrast agent utilized in medical imaging to improve the visibility of internal structures during X-ray and CT scans. Its pharmacodynamic action is largely due to its physical characteristics rather than any direct pharmacological impact on the body's systems.

ADMINISTRATION

Amidotrizoic acid, also known as diatrizoic acid, is an iodine-based contrast agent that improves the visibility of internal body structures during imaging tests such as X-rays and CT scans. The method of administration is determined by a healthcare professional based on the specific area being examined.

DOSAGE AND STRENGTH

Amidotrizoic acid (also known as diatrizoate) is a radiographic contrast agent available in various concentrations and formulations for specific medical imaging procedures. Dosages and strengths are highly dependent on the type of procedure and route of administration.

• Hypaque-76: A solution containing diatrizoate meglumine and diatrizoate sodium that is used for injections during angiography, urography, and CT scans.

• Cystografin: A diatrizoate meglumine injection used for retrograde cystography and voiding cystourethrography.

• Oral/Rectal Solutions: Formulations for oral or rectal use, such as Gastrografin, contain a combination of diatrizoate meglumine and diatrizoate sodium. An adult dose may be prepared by diluting the concentrate.

DRUG INTERACTIONS

Amidotrizoic acid may interact with several medications, including beta-blockers, diuretics, and certain antidepressants, potentially increasing the risk of serious reactions—especially in individuals with existing heart or thyroid conditions. It can also reduce the effectiveness of sodium iodide I-131 and may affect the excretion and blood levels of other drugs such as amoxicillin and metformin. Therefore, it’s important to inform your doctor of all medications you are taking before undergoing any procedure involving amidotrizoic acid.

FOOD INTERACTIONS

Amidotrizoic acid (diatrizoic acid) typically has no direct interactions with food; however, dietary guidelines may be required depending on the imaging procedure and route of administration. For gastrointestinal imaging, such as upper GI series or CT scans of the abdomen, patients are often advised to fast for several hours beforehand. In some cases, a clear liquid or low-residue diet may be recommended the day before the procedure, along with the use of laxatives or bowel preparations to ensure the gastrointestinal tract is clear for optimal imaging results.

CONTRAINDICATIONS

Amidotrizoic acid (also known as diatrizoic acid) is an iodinated contrast agent that carries several important contraindications. Before administration, a thorough review of the patient’s medical history is essential to ensure that the potential benefits outweigh any associated risks.

One major contraindication is hypersensitivity. This contrast agent should not be used in individuals with a known allergy to diatrizoic acid, its salts (such as diatrizoate sodium or diatrizoate meglumine), iodine, or any other ingredient in the formulation. Patients with a history of allergies—particularly to foods (like seafood), hay fever, or bronchial asthma—are at an increased risk for allergic reactions.

SIDE EFFECTS

Common side effects

• Gastrointestinal issues

• Sensations

• Injection site reactions

• Minor skin reactions: Mild rash or itching.

• Nausea or vomiting

• Pain, warmth, or discomfort at the injection site

• Redness or rash on the skin

• Headache and dizziness

• Diarrhea

Severe side effects

Allergic (Anaphylactoid) Reactions:

• Severe rash or hives

• Swelling of the face, lips, or tongue

• Difficulty breathing or swallowing

Cardiovascular Effects:

• Low blood pressure (hypotension) or, less commonly, high blood pressure

• Rapid or irregular heartbeat (tachycardia)

• In rare cases, serious complications like circulatory collapse or ventricular fibrillation

Kidney-Related Issues:

• Dehydration due to its osmotic properties

• Elevated creatinine levels, indicating impaired kidney function

Neurological Symptoms:

• Seizures or convulsions

• Confusion, restlessness, or agitation

• Temporary disturbances in vision or hearing

Pulmonary Complications:

• If the contrast medium is accidentally inhaled (aspirated), especially during oral administration, it may lead to pulmonary edema, a potentially serious condition involving fluid accumulation in the lungs.

OVER DOSE

An overdose of amidotrizoic acid (diatrizoate), an iodine-based contrast agent, can be life-threatening, with the cardiovascular and respiratory systems being most severely affected. Immediate medical intervention is essential in such cases.

TOXICITY

Amidotrizoic acid, a contrast agent used in medical imaging, can cause a range of toxic effects—from mild symptoms to serious, potentially life-threatening reactions such as anaphylaxis. Common side effects include nausea, vomiting, and discomfort at the injection site. More severe reactions may involve breathing difficulties, swelling, low blood pressure, rapid heart rate, and seizures. Its use should be avoided in individuals with iodine allergies or severe kidney impairment. Pregnant or breastfeeding women are advised to consult their healthcare provider before undergoing procedures involving this contrast agent.