Usage
- Gadobenate dimeglumine is a gadolinium-based contrast agent (GBCA) used in magnetic resonance imaging (MRI) of the central nervous system (CNS) to visualize lesions with abnormal blood-brain barrier or abnormal vascularity of the brain, spine, and associated tissues in adults and pediatric patients (including term neonates).
- It is also used in magnetic resonance angiography (MRA) to evaluate adults with known or suspected renal or aorto-ilio-femoral occlusive vascular disease.
- Pharmacologically, it is classified as a paramagnetic contrast agent.
- Its mechanism of action involves shortening the T1 relaxation times of water protons in tissues, thereby enhancing the signal intensity and improving the visualization of lesions during MRI.
Alternate Names
- Gadobenate dimeglumine is also known as Gd-BOPTA.
- A popular brand name under which it is marketed is MultiHance.
How It Works
- Pharmacodynamics: Gadobenate dimeglumine works by enhancing the contrast between normal and abnormal tissues during MRI. It distributes rapidly in the extracellular fluid and does not cross the intact blood-brain barrier. The gadolinium ion shortens the T1 relaxation time of water protons in its vicinity, leading to increased signal intensity on T1-weighted images. This enhanced contrast helps to delineate lesions with abnormal vascularity or disrupted blood-brain barrier.
- Pharmacokinetics:
- Absorption: Following intravenous administration, gadobenate dimeglumine is rapidly distributed into the extracellular space.
- Metabolism: It is not metabolized.
- Elimination: Gadobenate dimeglumine is primarily eliminated unchanged through glomerular filtration by the kidneys. A small fraction is excreted in bile. The elimination half-life in patients with normal renal function is approximately 1.2 to 2 hours.
- Mode of Action: The gadolinium ion in gadobenate dimeglumine acts as a paramagnetic contrast agent. Paramagnetic substances have unpaired electrons, which create a local magnetic field. This magnetic field interacts with the magnetic moments of nearby water protons, increasing the rate at which they return to their equilibrium state after being excited by the MRI scanner’s radiofrequency pulses. This effect is reflected in a shortening of the T1 relaxation time, which increases signal intensity on T1-weighted images.
- Gadobenate dimeglumine does not bind to specific receptors, inhibit enzymes, or modulate neurotransmitters.
- It is primarily excreted through renal pathways.
Dosage
Standard Dosage
Adults:
- CNS Imaging: 0.1 mmol/kg (0.2 mL/kg) administered as a rapid intravenous bolus injection.
- MRA (Renal and Aorto-ilio-femoral Vessels): 0.1 mmol/kg (0.2 mL/kg) administered as a rapid intravenous bolus injection. A test bolus may be used to determine the optimal scan delay time.
Children:
- CNS Imaging:
- Children 2 years and older: 0.1 mmol/kg (0.2 mL/kg) as a rapid intravenous bolus injection.
- Children under 2 years: 0.1 to 0.2 mL/kg (0.05 to 0.1 mmol/kg) as a rapid intravenous bolus injection.
- Pediatric safety for preterm neonates has not been established.
Special Cases:
- Elderly Patients: No dose adjustment is necessary, but renal function should be assessed.
- Patients with Renal Impairment: Due to the risk of Nephrogenic Systemic Fibrosis (NSF), Gadobenate dimeglumine should be avoided in patients with severe renal disease unless the diagnostic information is essential and not available with non-contrast enhanced MRI. In patients with moderate renal impairment, the dose should not be exceeded.
- Patients with Hepatic Dysfunction: No dosage adjustment is necessary.
- Patients with Comorbid Conditions: Assess renal function and adjust dose as needed.
Clinical Use Cases
The dosage for Gadobenate dimeglumine remains consistent across various clinical settings, including intubation, surgical procedures, mechanical ventilation, intensive care unit (ICU) use, and emergency situations. The standard adult and pediatric dosages apply.
Dosage Adjustments
Dose adjustments may be necessary in patients with renal impairment. In patients with severe renal impairment, the drug should be avoided. No dose adjustment is necessary for patients with hepatic impairment.
Side Effects
Common Side Effects:
- Headache
- Nausea
- Unusual or unpleasant taste in the mouth
Rare but Serious Side Effects:
- Nephrogenic Systemic Fibrosis (NSF) in patients with renal impairment
- Allergic reactions (hives, difficulty breathing, swelling of face, lips, tongue, or throat)
- Seizures
Long-Term Effects:
Gadolinium can be retained in the body for months or years. The long-term effects of this retention are not fully understood.
Adverse Drug Reactions (ADR):
Any severe allergic reaction, signs of NSF, or seizures should prompt immediate medical attention.
Contraindications
- Hypersensitivity to gadobenate dimeglumine or any of its components.
- Severe renal impairment (GFR < 30 mL/min/1.73 m²)
- Patients undergoing dialysis.
Drug Interactions
No clinically significant drug interactions have been reported with Gadobenate dimeglumine.
Pregnancy and Breastfeeding
- Pregnancy Safety Category: C (Animal studies have shown adverse effects on the fetus, but there are no adequate and well-controlled studies in humans. Use only if the potential benefit outweighs the potential risk to the fetus.)
- Limited data suggest that a small amount of the drug is excreted in breast milk. The manufacturer recommends interrupting breastfeeding for 24 hours after administration. However, most sources state that it is safe to continue breastfeeding. It is important to weigh the benefits of breastfeeding against the potential risks.
Drug Profile Summary
- Mechanism of Action: Shortens T1 relaxation times of water protons, enhancing MRI contrast.
- Side Effects: Headache, nausea, unusual taste; rarely, allergic reactions, NSF, seizures.
- Contraindications: Hypersensitivity, severe renal impairment, dialysis.
- Drug Interactions: None known.
- Pregnancy & Breastfeeding: Category C; Generally considered safe for breastfeeding.
- Dosage: Adults: 0.1 mmol/kg (0.2 mL/kg) IV; pediatric doses vary by age.
- Monitoring Parameters: Renal function (eGFR) before administration, especially in elderly patients or those with risk factors for renal impairment.
Popular Combinations
Gadobenate dimeglumine is not typically used in combination with other drugs for its primary indications.
Precautions
- General Precautions: Screen for renal impairment prior to administration, especially in patients over 60 years old, with hypertension, or diabetes.
- Specific Populations:
- Pregnant Women: Use only if essential and no safer alternatives.
- Breastfeeding Mothers: Generally considered safe.
- Children & Elderly: Follow age-specific dosage guidelines. Evaluate renal function in elderly patients.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Gadobenate dimeglumine?
A: Adults: 0.1 mmol/kg (0.2 mL/kg) IV. Pediatric dosages vary with age: children 2 years and older: 0.1 mmol/kg (0.2 mL/kg) IV, children under 2 years: 0.1 to 0.2 mL/kg IV.
Q2: What are the primary uses of Gadobenate dimeglumine?
A: MRI of the CNS and MRA of renal or aorto-ilio-femoral vessels.
Q3: How is Gadobenate dimeglumine eliminated from the body?
A: Primarily through renal excretion.
Q4: What is Nephrogenic Systemic Fibrosis (NSF)?
A: A serious, potentially fatal condition characterized by fibrosis of skin, muscle, and internal organs. It has been associated with the use of GBCAs, especially in patients with severe renal impairment.
Q5: Is Gadobenate dimeglumine safe for patients with liver disease?
A: Yes, no dosage adjustments are required for patients with hepatic impairment.
Q6: Can pregnant or breastfeeding women receive Gadobenate dimeglumine?
A: It should be used in pregnancy only if clearly needed. It is generally considered safe for breastfeeding mothers.
Q7: What are the most common side effects of Gadobenate dimeglumine?
A: Headache, nausea, and unusual taste in the mouth.
Q8: Are there any contraindications to using Gadobenate dimeglumine?
A: Yes, contraindications include hypersensitivity to the drug or its components, severe renal impairment, and patients on dialysis.
Q9: How should I monitor patients after administering Gadobenate dimeglumine?
A: Patients with renal impairment should be monitored for signs and symptoms of NSF. Assess for allergic reactions.
Q10: Is it safe to administer Gadobenate dimeglumine repeatedly?
A: Repeated administrations should be avoided unless absolutely necessary, and at least 7 days should elapse between doses.
