Gadamide

Uses

Gadamide is a gadolinium-based paramagnetic contrast agent for diagnostic magnetic resonance imaging (MRI) used for intravenous use:

• In patients with abnormal blood-brain barrier or abnormal vascularity of the brain, spine and associated tissues
• To provide contrast enhancement and facilitate visualization of lesions with abnormal vascularity in the liver in patients who are highly suspect for liver structural abnormalities on computed tomograph

How Gadamide works

Based on the behavior of protons when placed in a strong magnetic field, which is interpreted and transformed into images by magnetic resonance (MR) instruments. MR images are based primarily on proton density and proton relaxation dynamics. MR instruments are sensitive to two different relaxation processes, the T1 (spin-lattice or longitudinal relaxation time) and T2 (spin-spin or transverse relaxation time). Paramagnetic agents contain one or more unpaired electrons that enhance the T1 and T2 relaxation rates of protons in their molecular environment. In MRI, visualization of normal and pathological brain, spinal and hepatic tissue depends in part on variations in the radio frequency signal intensity that occur with changes in proton density, alteration of the T1, and variation in T2. When placed in a magnetic field, gadoversetamide shortens the T1 and T2 relaxation times in tissues where it accumulates. At the recommended dose, the effect is primarily on T1 relaxation time, and produces an increase in signal intensity (brightness). Gadamide does not cross the intact blood-brain barrier; therefore, it does not accumulate in normal brain tissue or in CNS lesions that may have a normal blood-brain barrier (e.g., cysts, mature post-operative scars). Abnormal vascularity or disruption of the blood-brain barrier allows accumulation of gadoversetamide in lesions such as neoplasms, abscesses, and subacute infarcts.

Dosage

Gadamide dosage

Bolus peripheral intravenous injection at a dose of 0.2 mL/kg (0.1 mmol/kg). Follow injection with a 5 mL normal saline flush. Complete imaging procedure within 1 hour of injection

Side Effects

Most common adverse reactions (incidence >2%) are: headache, vasodilatation, taste perversion, dizziness, nausea and paresthesia.

Precaution

Nephrogenic Systemic Fibrosis (NSF) has occurred in patients with impaired elimination of Gadolinium Based Contrast Agents (GBCAs). Higher than recommended dosing or repeat dosing appears to increase the risk.

Hypersensitivity reactions including fatal reactions have occurred, particularly in patients with history of allergy, drug reactions, or other hypersensitivity-like disorders. Monitor these patients closely during and after administration of gadoversetamide.

Gadolinium is retained for months or years in brain, bone, and other organs.

Acute Kidney Injury (AKI) has occurred in patients with preexisting renal insufficiency. Use the lowest necessary dose of gadoversetamide in these patients.

Interference with laboratory measurements of serum iron, copper and zinc and in the measurement of serum calcium using the ortho-cresophthalin complexone (OCP) colorimetric method has occurred.

Interaction

Drug interactions with other contrast agents and other drugs have not been studied.

Food Interaction

Gadamide Hypertension interaction

[Major] Gadolinium- based contrast agents (GBCAs) such as gadopentetate dimeglumine, gadoteridol and gadodiamide are contraindicated in patients with chronic, severe kidney disease (glomerular filtration rate, GFR 60 years, hypertension or diabetes).

Always estimate the glomerular filtration rate (GFR) through laboratory testing.

Gadamide Drug Interaction

Unknown: aripiprazole, aripiprazole, lorazepam, lorazepam, phenazopyridine, phenazopyridine, diphenhydramine, diphenhydramine, omega-3 polyunsaturated fatty acids, omega-3 polyunsaturated fatty acids, clonazepam, clonazepam, thyroid desiccated, thyroid desiccated, vitamin a & d topical, vitamin a & d topical, multivitamin, multivitamin, lisdexamfetamine, lisdexamfetamine

Gadamide Disease Interaction

Major: renal impairmentModerate: seizures, allergies

Volume of Distribution

• 162 ± 25 mL/kg [normal subjects]

Half Life

Distribution 13.3 ± 6.8 (mean) minutes, elimination 103.6 ± 19.5 (mean) minutes.

Clearance

• 72 +/- 16.3 mL/hr/kg [healthy]

Elimination Route

The mean cumulative urinary excretion of gadoversetamide at 72 hours was approximately 93.5% for renal impaired patients and 95.8% for subjects with normal renal function

Pregnancy & Breastfeeding use

use Gadamide only if imaging is essential during pregnancy and cannot be delayed. Radiolabeled gadoversetamide (153Gd) was excreted in the milk of lactating rats receiving a single intravenous dose of 0.1 mmol/kg. Women should discontinue nursing and discard breast milk up to 72 hours after Gadamide administration

Contraindication

Chronic, severe kidney disease (glomerular filtration rate, GFR<30 mL/min/1.73m2), acute kidney injury. Prior hypersensitivity reactions to gadolinium, versetamide or any of the inert ingredients

Special Warning

Pediatric Use: The safety and effectiveness of Gadamide in pediatric patients have not been established. Pediatric patients may be particularly vulnerable to adverse GBCA reactions due to renal immaturity or unrecognized renal insufficiency.

Geriatric Use: Since gadoversetamide is cleared from the body by glomerular filtration, the risk of adverse reactions may be greater in patients with impaired renal function (GFR ≥30 and <90 mL/min/1.73m2). Due to the risk for NSF, estimate the GFR through laboratory testing for patients >60 years of age

Acute Overdose

Clinical consequences of overdosage with Gadamide have not been reported. Treatment of overdose is directed toward supporting vital functions and prompt institution of symptomatic therapy. Gadamide has been shown to be dialyzable

Storage Condition

Gadamide should be stored at 20°C to 25°C and protected from light and freezing. Gadamide may be stored at 37°C for up to one month in a contrast media warmer utilizing circulating warm air. For periods longer than one month, store at 20°C to 25°C

Innovators Monograph

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