Gadodiamide

Approved Indications:

• Contrast agent used in magnetic resonance imaging (MRI) to enhance the quality of diagnostic images.
• Specifically indicated for contrast enhancement of the central nervous system (brain and spinal cord).
• Visualization of abnormalities such as tumors, inflammation, vascular malformations, and lesions in the brain, spinal cord, and other soft tissues.

Off-label/Clinically Accepted Uses:

• Contrast enhancement in MRI of other body parts such as liver, kidneys, and musculoskeletal system, when detailed soft tissue imaging is required.
• Assessment of blood-brain barrier integrity.
• Follow-up evaluation of known lesions or abnormalities.

Adults and Pediatrics:

• Recommended Dose: 0.1 mmol/kg body weight (typically 0.2 mL/kg of 0.5 mmol/mL gadodiamide solution).
• Administration Route: Intravenous injection, preferably by bolus injection.
• Injection Rate: Usually injected over 20 to 60 seconds, followed by a flush of saline.
• Repeat Dosing: Additional doses may be given if clinically justified but should be separated by sufficient time to allow elimination (usually 24 hours or more).

Special Populations:

• Renal Impairment: Use with caution; reduce dose or avoid in patients with severe renal impairment due to risk of nephrogenic systemic fibrosis (NSF).
• Elderly: No specific dose adjustment recommended but monitor renal function closely.
• Pediatrics: Safety and efficacy established in children; use same dose per body weight as adults.

Gadodiamide is a gadolinium-based contrast agent (GBCA) that works by altering the local magnetic properties of tissues during MRI scanning. Gadolinium is a paramagnetic metal ion that shortens the T1 relaxation time of nearby water protons, leading to increased signal intensity and contrast enhancement on T1-weighted MRI images. Gadodiamide is a non-ionic, linear chelate of gadolinium designed to reduce free gadolinium ion toxicity by tightly binding the metal ion, allowing it to safely circulate and enhance visualization of abnormal tissues, blood vessels, and disrupted blood-brain barrier areas.

• Absorption: Administered intravenously; 100% bioavailability.
• Distribution: Rapidly distributes throughout the extracellular fluid; low protein binding.
• Metabolism: Not metabolized; remains chemically stable in vivo.
• Elimination: Primarily eliminated unchanged via renal excretion through glomerular filtration.
• Half-life: Approximately 1.5 hours in patients with normal renal function; significantly prolonged in renal impairment.
• Excretion: About 95% excreted in urine within 24 hours.

• Pregnancy: Classified as FDA Pregnancy Category C. Animal reproduction studies are inadequate or lacking; use during pregnancy only if clearly needed and potential benefits outweigh risks.
• Lactation: Unknown if gadodiamide is excreted in human milk; caution advised. Breastfeeding mothers should consult healthcare providers before MRI with gadodiamide contrast.

• Primary Class: MRI Contrast Agent
• Subclass: Gadolinium-based contrast agent (Non-ionic, linear chelate)

• Known hypersensitivity to gadodiamide or any of its components.
• Patients with severe renal impairment (glomerular filtration rate <30 mL/min/1.73 m²), unless the diagnostic information is essential.
• History of nephrogenic systemic fibrosis (NSF).

• Nephrogenic Systemic Fibrosis (NSF): Serious and potentially fatal condition reported in patients with severe renal impairment exposed to gadolinium-based contrast agents. Avoid or use with extreme caution in such patients.
• Allergic Reactions: Anaphylactoid and hypersensitivity reactions possible; emergency equipment and medications should be readily available.
• Renal Function Monitoring: Assess renal function prior to administration, especially in at-risk patients (elderly, diabetics).
• Pregnancy & Lactation: Use only if clearly necessary.
• Extravasation: Careful intravenous administration to avoid tissue damage.
• Gadolinium Retention: Small amounts of gadolinium may remain in the brain and other tissues after repeated administration; clinical significance remains unclear.

Common Adverse Effects:

• Headache
• Nausea
• Dizziness
• Injection site reactions (pain, swelling, redness)
• Taste perversion (metallic taste)

Less Common and Serious Side Effects:

• Allergic reactions: rash, urticaria, pruritus
• Anaphylactic or anaphylactoid reactions (rare)
• Nephrogenic systemic fibrosis (very rare, primarily in patients with renal failure)
• Hypotension
• Injection site extravasation causing local tissue irritation

• No significant drug-drug interactions have been reported as gadodiamide is not metabolized by liver enzymes.
• No known interactions with food or alcohol.
• Concomitant nephrotoxic drugs may increase risk of renal toxicity; caution advised.

• Increased caution and contraindications for use in patients with severe renal impairment due to risk of NSF.
• Regulatory agencies (FDA, EMA) recommend using lowest effective dose and avoiding repeated doses when possible.
• Warnings about gadolinium retention have led to recommendations to limit use in patients requiring multiple contrast-enhanced MRIs.
• Newer macrocyclic GBCAs are preferred in many guidelines over linear agents like gadodiamide due to improved stability and lower retention risk.

• Store at controlled room temperature: 20°C to 25°C (68°F to 77°F).
• Protect from freezing; do not freeze the solution.
• Keep the container tightly closed and protect from light.
• Use immediately after opening or follow vial-specific guidelines for single-use vials.
• Dispose of any unused portion according to local regulations.