Usage
- Meglumine diatrizoate + sodium diatrizoate is prescribed for radiographic examination of the gastrointestinal (GI) tract. It’s particularly useful when barium sulfate, a more viscous contrast agent, is contraindicated due to potential risks like perforation or aspiration. It is also used for computed tomography (CT) scans of the torso, often in conjunction with intravenous contrast agents, to enhance the visualization of the bowel.
- Pharmacological Classification: Radiopaque contrast medium, diagnostic agent.
- Mechanism of Action: This combination works by opacifying the GI tract, making it appear clearly on X-rays. Its hyperosmolarity facilitates bowel cleansing by drawing water into the intestinal lumen, inducing a laxative effect.
Alternate Names
- Gastrografin
- MD-Gastroview
- Hypaque (sodium diatrizoate alone)
- Urografin (combination of sodium and meglumine salts)
- MD-76 R (injectable solution)
How It Works
- Pharmacodynamics: Meglumine diatrizoate and sodium diatrizoate are water-soluble, iodinated compounds that absorb X-rays, allowing visualization of the GI tract during imaging procedures. They are poorly absorbed systemically from the GI tract. Their hyperosmolarity causes a shift of fluid into the intestinal lumen, producing a laxative effect.
- Pharmacokinetics: The combination is administered orally or rectally. Minimal absorption occurs from the intact GI tract, allowing for localized opacification. Absorbed diatrizoate is excreted primarily via the kidneys.
- Mode of Action: The iodine component of the diatrizoate molecules absorbs X-rays. The salts are not metabolized and primarily undergo renal excretion. The hyperosmolarity of the solution affects water balance in the GI tract.
- Elimination Pathways: Primarily renal excretion. Small amounts may be eliminated through the liver and intestines.
Dosage
Standard Dosage
Adults:
- Oral: 30 to 90 mL, depending on the examination and patient size.
- Rectal: Dilute 240 mL of meglumine diatrizoate + sodium diatrizoate in 1000 mL of tap water.
Children:
- Oral:
- < 5 years: 30 mL (may dilute 1:1). Rectal: Dilute 30 mL in 150 mL tap water (1:5 dilution)
- 5-10 years: 60 mL (may dilute 1:1). Rectal: Dilute 90 mL in 500 mL tap water.
- Note: For children <10 kg and debilitated children, dilute 1 part contrast medium with 3 parts water.
Special Cases:
- Elderly Patients and Debilitated Patients: 1:1 dilution is recommended. Reduce dose based on clinical status and monitor hydration and electrolytes.
- Patients with Renal Impairment: Use with caution due to the risk of contrast-induced nephropathy. Adequate hydration is crucial.
- Patients with Hepatic Dysfunction: Use caution, especially in patients with combined hepatic and renal disease.
- Patients with Comorbid Conditions: Dehydration and electrolyte imbalances should be corrected before administration. Consider underlying medical conditions. Monitor for adverse reactions.
Clinical Use Cases
Dosage adjustments may be necessary based on the specific clinical context and are typically determined by the radiologist.
- Intubation: Not applicable.
- Surgical Procedures: Pre-operative bowel cleansing (dosage as above).
- Mechanical Ventilation: Not applicable.
- Intensive Care Unit (ICU) Use: May be used for diagnostic imaging of the GI tract in critically ill patients, but with careful monitoring and dose adjustments.
- Emergency Situations: May be used in suspected GI perforation.
Side Effects
Common Side Effects:
- Nausea
- Vomiting
- Diarrhea
- Abdominal cramping
- Rash
- Itching
- Heartburn
- Dizziness
- Headache
Rare but Serious Side Effects:
- Allergic reactions (anaphylaxis)
- Pulmonary edema (after aspiration)
- Renal failure
- Cardiac arrhythmias
- Hypotension
- Thrombosis
Adverse Drug Reactions (ADR):
- Severe allergic reactions (anaphylaxis), requiring immediate medical intervention.
- Pulmonary complications following aspiration, including pulmonary edema, pneumonitis, and even death.
- Contrast-induced nephropathy.
Contraindications
- Hypersensitivity to diatrizoate salts or any component of the formulation.
- Severe dehydration.
- Known or suspected perforation of the GI tract (for oral administration).
- Severe debility.
Drug Interactions
- Metformin: Increased risk of lactic acidosis, especially in patients with renal impairment. Metformin should be temporarily discontinued before and after contrast administration.
- Radioactive Iodine (I-131, I-123): Interference with thyroid uptake, reducing diagnostic and therapeutic efficacy for several weeks.
- Other contrast agents: Increased risk of renal toxicity, especially in patients with liver dysfunction.
Pregnancy and Breastfeeding
- Pregnancy Category B: Diatrizoate crosses the placenta. Use only when clearly needed, weighing the benefits against potential risks to the fetus.
- Breastfeeding: Diatrizoate is excreted in breast milk. Caution is advised. Consider interrupting breastfeeding for 24 hours after administration.
Drug Profile Summary
- Mechanism of Action: Radiopaque contrast medium.
- Side Effects: Nausea, vomiting, diarrhea, allergic reactions, pulmonary complications (after aspiration).
- Contraindications: Hypersensitivity, severe dehydration, GI perforation.
- Drug Interactions: Metformin, radioactive iodine, other contrast agents.
- Pregnancy & Breastfeeding: Category B; use with caution.
- Dosage: See detailed dosage guidelines above.
- Monitoring Parameters: Hydration status, electrolyte levels, renal function, allergic reactions.
Precautions
- General Precautions: Evaluate hydration and electrolyte status, renal and hepatic function, and history of allergies or prior reactions to contrast agents.
- Specific Populations: See “Special Cases” under Dosage.
- Lifestyle Considerations: Ensure adequate hydration.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Meglumine Diatrizoate + Sodium Diatrizoate?
A: See detailed dosage guidelines above.
Q2: What are the common side effects?
A: Nausea, vomiting, diarrhea, abdominal cramps, rash, itching, heartburn.
Q3: What are the contraindications?
A: Hypersensitivity to the drug, severe dehydration, and known or suspected GI perforation.
Q4: Can it be used in pregnant or breastfeeding women?
A: Use with caution. It is classified as Pregnancy Category B. It’s recommended to interrupt breastfeeding for 24 hours after administration.
A: Increases the risk of lactic acidosis. Metformin should be temporarily discontinued before and after contrast administration.
Q6: What are the potential complications of aspiration?
A: Pulmonary edema, pneumonitis, and potentially death.
Q7: How does it affect thyroid function tests?
A: Can interfere with radioactive iodine uptake studies. Thyroid function tests should be performed before contrast administration or delayed for several weeks.
Q8: What precautions should be taken in patients with renal impairment?
A: Use cautiously with meticulous hydration, as it can worsen renal function.
Q9: What is the mechanism of action?
A: It acts as a radiopaque contrast medium by absorbing X-rays, allowing visualization of the GI tract. It also exerts a laxative effect due to its hyperosmolarity.
