Usage
Diatrizoic acid, an iodinated radiopaque contrast medium, is primarily used for radiographic examination of the gastrointestinal (GI) tract, especially when barium sulfate is contraindicated (e.g., suspected perforation). It is also employed for visualizing the pharynx, esophagus, and assessing swallowing mechanisms. This agent facilitates enhanced visualization during fluoroscopic and radiographic procedures. Pharmacologically, it is classified as a radiographic contrast medium. Its mechanism of action involves absorbing X-rays, thereby increasing the radiopacity of the GI tract and other structures, allowing for clearer visualization on X-ray images.
Alternate Names
Diatrizoic acid is also available as salts like diatrizoate meglumine and diatrizoate sodium. Common brand names for formulations containing these salts include Gastrografin, Hypaque, and Cystografin.
How It Works
Pharmacodynamics: Diatrizoic acid works by attenuating X-rays due to its high iodine content, resulting in increased contrast between the targeted organ and surrounding tissues on radiographic images. It does not exert any direct pharmacological effect on the body.
Pharmacokinetics:
- Absorption: When administered orally or rectally, diatrizoic acid is minimally absorbed from the GI tract.
- Distribution: It distributes within the GI lumen. For other formulations (e.g., intra-arterial or intravenous), the distribution depends on the administration route.
- Metabolism: Diatrizoic acid is not metabolized.
- Elimination: Following oral or rectal administration, it is eliminated primarily unchanged in the feces. Intravenously administered diatrizoate is excreted by the kidneys.
Mode of Action: Diatrizoic acid’s mode of action is purely physical. Its high atomic weight and iodine content lead to increased absorption of X-rays, creating the desired contrast on radiographic images. There is no receptor binding, enzyme inhibition, or neurotransmitter modulation involved.
Dosage
Standard Dosage
Adults:
Oral or rectal administration: 30 to 90 mL, depending on the examination and patient size.
Children:
- Up to 5 years: 30 mL.
- 5 to 10 years: 60 mL.
Special Cases:
- Elderly/Debilitated Patients: A 1:1 dilution with water, carbonated beverages, milk, or mineral oil is recommended.
- Infants weighing < 10 kg/Debilitated Children: Dilute 1 part contrast medium with 3 parts water.
- Patients with Renal/Hepatic Impairment: Caution is advised, and dosage adjustments may be needed, especially for intravenous formulations. Further research is needed for specific oral/rectal dose adjustments.
- Patients with Comorbid Conditions: Exercise caution in patients with dehydration, electrolyte imbalances, severe renal or hepatic disease, hyperthyroidism, or known hypersensitivity to diatrizoic acid.
Clinical Use Cases
The provided sources primarily address diatrizoic acid use for gastrointestinal imaging and cystourethrography. Dosages for other clinical scenarios involving intravenous administration should be consulted from other relevant medical resources. The use of diatrizoic acid in clinical use cases such as intubation, surgical procedures, mechanical ventilation, intensive care unit (ICU) use, and emergency situations is not specifically addressed in the provided literature.
Dosage Adjustments
Dose adjustments may be necessary in cases of renal or hepatic impairment, and in pediatric and elderly patients. Always consider patient-specific factors and clinical context.
Side Effects
Common Side Effects
Nausea, vomiting, diarrhea, injection site reactions (pain, warmth), abdominal cramping.
Rare but Serious Side Effects
Allergic reactions (rash, hives, itching, difficulty breathing, swelling), kidney problems, changes in heart rate and blood pressure.
Long-Term Effects
Generally, no long-term adverse effects are associated with the oral or rectal administration of diatrizoic acid, due to its minimal absorption.
Adverse Drug Reactions (ADR)
Severe allergic reactions (anaphylaxis) require immediate medical intervention.
Contraindications
Hypersensitivity to diatrizoic acid or its salts, severe dehydration, known perforation or obstruction of the GI tract (for oral administration), pregnancy (unless clearly necessary).
Drug Interactions
Limited information is available regarding drug interactions specifically with oral or rectal diatrizoic acid. No significant interactions have been definitively established. However, potential interactions may exist with certain medications, so caution is advised, especially for formulations administered intravenously.
Pregnancy and Breastfeeding
Pregnancy Safety Category: C (US FDA). Use only if clearly needed, as safety in pregnancy has not been established. Excretion in breast milk is known to occur for intravenous formulations; the safety of oral/rectal formulations during breastfeeding hasn’t been fully established. Exercise caution and consider interrupting breastfeeding temporarily or using an alternative imaging method.
Drug Profile Summary
- Mechanism of Action: Enhances radiographic contrast by absorbing X-rays.
- Side Effects: Nausea, vomiting, diarrhea, allergic reactions.
- Contraindications: Hypersensitivity, severe dehydration, GI perforation/obstruction, pregnancy (unless essential).
- Drug Interactions: Limited information available, exercise caution.
- Pregnancy & Breastfeeding: Use with caution if clearly needed.
- Dosage: Varies by examination, age, and route of administration. Refer to dosage guidelines.
- Monitoring Parameters: Observe for allergic reactions and GI disturbances.
Popular Combinations
No specific combinations are mentioned in the provided text. Drug combinations are unlikely for oral or rectal preparations.
Precautions
Screen for allergies to iodine or contrast media. Ensure adequate hydration, particularly in children and elderly individuals. Exercise caution in patients with renal or hepatic impairment, thyroid disorders, and cardiovascular disease.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Diatrizoic Acid?
A: The dosage varies depending on the examination, patient age, and administration route. Adult oral/rectal doses typically range from 30 to 90 mL. Pediatric doses are lower, typically 30 mL for children up to 5 years and 60 mL for those aged 5 to 10 years. Dosage modifications are required for elderly, debilitated patients, and infants.
Q2: Can Diatrizoic Acid be used in pregnant or breastfeeding women?
A: Diatrizoic acid should be used cautiously during pregnancy and breastfeeding only if the benefits outweigh the potential risks. It is classified as Pregnancy Category C by the US FDA. Consult a specialist and consider alternative methods if possible.
Q3: What are the most common side effects of Diatrizoic Acid?
A: Common side effects include nausea, vomiting, diarrhea, and injection site reactions (for parenteral forms).
Q4: Are there any contraindications to using Diatrizoic Acid?
A: Contraindications include known hypersensitivity to diatrizoic acid or its salts, severe dehydration, and GI tract perforation or obstruction (for oral use).
Q5: How is Diatrizoic Acid administered?
A: Diatrizoic acid can be administered orally, rectally, or parenterally (intravenously, intra-arterially) depending on the specific diagnostic procedure.
Q6: How does Diatrizoic Acid work?
A: Diatrizoic acid absorbs X-rays due to its high iodine content. This increases the contrast between the targeted organ and the surrounding tissues on X-ray images, allowing for clearer visualization.
Q7: What are the signs of an allergic reaction to Diatrizoic Acid?
A: Allergic reactions can range from mild (rash, hives, itching) to severe (difficulty breathing, swelling of the face, throat, or tongue, anaphylaxis). Immediate medical attention is required for severe reactions.
Q8: How should Diatrizoic Acid be stored?
A: Store at room temperature (20°C to 25°C / 68°F to 77°F) and protect from light. Diluted solutions should be used immediately.
Q9: Does Diatrizoic Acid interact with other medications?
A: Drug interactions are more relevant for intravenous formulations. Limited data exists for interactions with oral and rectal forms. It’s crucial to inform the healthcare provider about all medications the patient is taking to minimize potential risks.
Please note that this information is current as of February 16, 2025, and may be subject to change with future research and updates. Always consult the latest medical references and product information before making clinical decisions.
