Dosing and uses of Magnevist (gadopentetate)
Adult dosage forms and strengths
injectable solution
- 469.01mg/mL
MRI Contrast Agent
0.2 mL/kg IV bolus; not to exceed infusion rate of 10 mL/15 seconds
Dosing in patients > 286 pounds not studied
Pediatric dosage forms and strengths
injectable solution
- 469.01mg/mL
MRI Contrast Agent
<2 years: Safety and efficacy not established
>2 years: As adults; 0.2 mL/kg IV bolus; not to exceed infusion rate of 10 mL/15 seconds
Warnings
Black box warnings
Risk for nephrogenic systemic fibrosis (NSF) with acute or chronic renal insufficiency (GFR <30 mL/min/1.73 m²), hepatorenal syndrome, or acute renal insufficiency resulting from perioperative liver transplant
NSF affects internal organs, skin, and muscle and can be fataL
Only use if essential and MRI cannot not provide appropriate diagnostic image
Screen for renal dysfunction, not to exceed recommended dosage, and allow for drug elimination before giving subsequent doses
Contraindications
History of severe hypersensitivity reactions
Cautions
Screen all patients for renal dysfunction
Thrombotic syndromes, anemia, hepatic/renal impairment, hemoglobinopathies (sickle cell anemia)
Risk for nephrogenic systemic fibrosis (NSF) in patients w/acute or chronic severe renal insufficiency, hepatorenal syndrome or in perioperative liver transplantation period (see Black box warnings)
Risk of hypotension
Site of injection may develop thrombosis
History of grand mal seizure
Safety of repeat doses not studied
Brain deposits
- 7/28/2015: FDA is investigating the risk of brain deposits following repeated use of gadolinium-based contrast agents (GBCAs) for MRI
- Recent publications in the medical literature have reported that deposits of GBCAs remain in the brains of some patients who undergo ≥4 contrast MRI scans, long after the last administration
- It is unknown whether these gadolinium deposits are harmful or can lead to adverse health effects
- Early data in rat studies show that linear GBCAs are more prone to dissociation into free gadolinium and demonstrate greater brain deposition than macrocyclic GBCAs, which are less prone to dissociation
Pregnancy and lactation
Pregnancy category: C
Lactation: enters breast milk; use with caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Magnevist (gadopentetate)
Mechanism of action
Paramagnetic agent; exposure to external magnetic field in gadopentetate may induce a large magnetic field. The local magnetism may change proton density and spin characteristics, which it is then detected by the imaging device
Pharmacokinetics
Excretion: urine (90-100%)
Dialyzable: yes
Vd: 266 mL/kg; does not cross intact brain barrier
Half-life: 1.6 hr
Excretion: Urine (91%)
