In the rat hippocampal region, a single intracerebral injection of gadoteridol (1 mM) increases rAAV1 distribution [1].

Animal/Disease Models: SD (SD (Sprague-Dawley)) rats (3 -5 months) [1]
Doses: 1 mM/rat
Route of Administration: Intracerebral injection once, co-infusion with rAAV1 or AAV5
Experimental Results: Increased transduction efficiency of AAV1, But AAV5 is not added.

Absorption, Distribution and Excretion
From population PK model of pediatric subjects receiving a single intravenous dose of 0.1 mmol/kg of gadoteridol, the mean Cmax was 0.66 ± 0.21 mmol/L in pediatric subjects 2 years to 6 years of age, 0.58 ± 0.06 mmol/L in pediatric subjects 6 years to 12 years of age, and 0.68 ± 0.12 mmol/L in adolescent subjects older than 12 years. The mean AUC0-∞ was 0.74 ± 0.20 mmol/L*h in pediatric subjects 2 years to 6 years of age, 0.74 ± 0.09 mmol/L*h in pediatric subjects 6 years to 12 years of age, and 0.98 ± 0.09 mmol/L*h in adolescent subjects older than 12 years of age. Pharmacokinetic simulations indicate similar half-life, AUC, and Cmax values for ProHance in pediatric subjects less than 2 years of age when compared to those reported for adults.
Gadoteridol is eliminated in the urine with 94.4 ± 4.8% (mean ± SD) of the dose excreted within 24 hours post-injection. Over 80% of the dose was recovered in urine for pediatric subjects after 10 hours. In patients with moderately and severely impaired renal function about 97% and 76% of the administered dose was recovered in the urine within 7 days and 14 days, respectively.
The plasma distribution volume (mean ± SD) for the non-renally impaired adults was 0.205 ± 0.025 L/kg.Following GBCA administration, gadolinium is present for months or years in the brain, bone, skin, and other organs.
The renal and plasma clearance rates (1.41 ± 0.33 mL/ min/kg and 1.50 ± 0.35 mL/ min/kg, respectively) of gadoteridol are essentially identical, indicating no alteration in elimination kinetics on passage through the kidneys and that the drug is essentially cleared through the kidney. The mean serum clearance of gadoteridol in patients with normal renal function was 116.14 ± 26.77 mL/min, compared to 37.2 ± 16.4 mL/min in patients with mild to moderate renal impairment and 16.0 ± 3.0 mL/min in patients with severe renal impairment.
... The physicochemical properties of gadoteridol, a macrocyclic nonionic gadolinium complex, were studied together with its pharmacokinetics and biodistribution in rats and dogs. ... Studies in rats were conducted after single iv injections at 0.1 or 0.35 mmol/kg using (153)Gd-labeled gadoteridol or with seven daily doses of 0.1 mmol/kg to examine the levels of residual gadolinium in organs. Nonradioactive biodistribution and excretion studies were performed in dogs following injection at 0.1 mmol/kg. ... After injection, the dose was rapidly cleared from rat blood and excreted such that more than 90% of the dose appeared in the urine within 4 hr of injection. At 7 and 14 days postinjection, only extremely low levels of gadolinium were observed in liver and bone; these levels were two to eight times lower than the levels reported after the injection of gadopentetate dimeglumine. ... Differences observed in the long-term retention of gadolinium between gadoteridol and gadopentetate dimeglumine were consistent with the reported greater in vivo resistance to transmetallation of gadolinium macrocycles compared with the linear gadolinium chelate molecules.
... To assess the safety and pharmacokinetics of gadoteridol injection (0.5 M) ... 18 healthy male volunteers ... were assigned to one of six dosing groups: 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3 mmol/kg gadoteridol (0.5 M), in an ascending dose study. Physical examination, vital signs, electrocardiogram, clinical laboratory tests, and serum and urine samples were obtained at selected time points before and after administration of gadoteridol. ... No significant changes in vital signs, physical examination, clinical laboratory values, or electrocardiogram, that were believed ... to be related to the administration of the contrast agent, were observed. A single adverse event (transient hive) believed to be related to contrast agent administration was observed in one volunteer. Pharmacokinetic data show that the elimination half-life and the distribution half-life were independent of the dose used. The mean distribution half-life was 0.20 +/- 0.04 hours, the mean elimination half-life was 1.57 +/- 0.08 hours, and greater than 94% of the drug was excreted in the urine in 24 hours.
Gadoteridol is eliminated in the urine with 94.4 + or - 4.8% (mean + or - SD) of the dose excreted within 24 hours post-injection.
Gadoteridol does not cross the intact blood-brain barrier and, therefore, does not accumulate in normal brain or in lesions that have a normal blood-brain barrer, e.g., cysts, mature post-operative scars, etc. However, disruption of the blood-brain barrer or abnormal vascularity allows accumulation of gadoteridol in lesions such as neoplasms, abscesses, and subacute infarcts. The pharmacokinetics of ProHance in various lesions is not known.
For more Absorption, Distribution and Excretion (Complete) data for GADOTERIDOL (7 total), please visit the HSDB record page.

---

Metabolism / Metabolites
It is unknown if biotransformation or decomposition of gadoteridol occurs in vivo.
It is unkown if biotransformation or decomposition of gadoteridol occur in vivo.

---

Biological Half-Life
The elimination half-life (mean ± SD) is about 1.57 ± 0.08 hours. From population PK model of pediatric subjects receiving a single intravenous dose of 0.1 mmol/kg of gadoteridol, the mean distribution half-life (t_1/2,alpha) was 0.14 ± 0.04 hours in pediatric subjects 2 years to 6 years of age, 0.18 ± 0.07 hours in pediatric subjects 6 years to 12 years of age, and 0.20 ± 0.07 hours in adolescent subjects older than 12 years of age. The mean elimination half-life (t_1/2,beta) was 1.32 ± 0.006 hours in pediatric subjects 2 years to 6 years, 1.32 ± 0.07 hours in pediatric subjects 6 years to 12 years of age, and 1.61 ± 0.19 hours in adolescent subjects older than 12 years of age. Pharmacokinetic simulations indicate similar half-life values for gadoteridol in pediatric subjects less than 2 years of age when compared to those reported for adults. In patients with impaired renal function, the serum half-life of gadoteridol is prolonged. After intravenous injection of 0.1 mmol/kg, the elimination half-life of gadoteridol was 10.65 ± 0.06 hours in mild to moderately impaired patients (creatinine clearance 30 to 60 mL/min) and 9.10±0.26 hours in severely impaired patients not on dialysis (creatinine clearance 10 to 30 mL/min).
The pharmacokinetics of intravenously administered gadoteridol in normal subjects conforms to a two-compartment open model with mean distribution and elimination half-lives (reported as mean + or - SD) of about 0.20 + or - 0.04 hours and 1.57 + or - 0.08 hours, respectively.
... 18 healthy male volunteers ... were assigned to one of six dosing groups: 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3 mmol/kg gadoteridol (0.5 M), in an ascending dose study. ...Pharmacokinetic data show that the elimination half-life and the distribution half-life were independent of the dose used. The mean distribution half-life was 0.20 +/- 0.04 hours, the mean elimination half-life was 1.57 +/- 0.08 hours... .

Toxicity Summary
IDENTIFICATION AND USE: Gadoteridol is used as injectable contrast medium for Magnetic Resonance Imaging (MRI). HUMAN EXPOSURE AND TOXICITY: Gadolinium-based contrast agents (GBCAs) increase the risk for nephrogenic systemic fibrosis (NSF) among patients with impaired elimination of the drugs. Avoid use of GBCAs in these patients unless the diagnostic information is essential and not available with non-contrasted MRI or other modalities. NSF may result in fatal or debilitating systemic fibrosis affecting the skin, muscle and internal organs. The risk for NSF appears highest among patients with: chronic, severe kidney disease , or acute kidney injury. Screen patients for acute kidney injury and other conditions that may reduce renal function. For patients at risk for chronically reduced renal function (older than 60 years, hypertension or diabetes), estimate the glomerular filtration rate (GFR) through laboratory testing. For patients at highest risk for NSF, do not exceed the recommended ProHance dose and allow a sufficient period of time for elimination of the drug from the body prior to re-administration. The possibility of a reaction, including serious, life threatening, or fatal, anaphylactic or cardiovascular reactions, or other idiosyncratic reactions, should always be considered, especially in those patients with a history of a known clinical hypersensitivity or a history of asthma or other allergic respiratory disorders. The literature describe a case of vasovagal response and anaphylactoid reaction during iv administration of gadoteridol. In an in vitro test, gadoteridol did not demonstrate any potential to hemolyze human erythrocytes when incubated in high concentrations with whole blood, suggesting there is little probability gadoteridol will cause hemolysis in vivo. ANIMAL STUDIES: Gadopentetate dimeglumine (Magnevist), gadoteridol (ProHance), gadodiamide (Omniscan), and gadoversetamide (Optimark) were evaluated at standard concentration and compared with a control (physiologic saline) and the conventional ionic radiographic contrast medium meglumine diatrizoate (Renografin 60) in mice. Of the four MR contrast agents, gadopentetate dimeglumine caused the greatest tissue damage, and gadoteridol and gadodiamide-the two lowest osmolar agents-the least after sc injection in the hindlimb. ProHance administered to rats at 10 mmol/kg/day (33 times the maximum recommended human dose of 0.3 mmol/kg or 6 times the human dose based on a mmol/m comparison) for 12 days during gestation doubled the incidence of postimplantation loss. When rats were administered 6.0 or 10.0 mmol/ kg/day for 12 days, an increase in spontaneous locomotor activity was observed in the offspring. ProHance increased the incidence of spontaneous abortion and early delivery in rabbits administered 6 mmol/kg/day (20 times the maximum recommended human dose or 7 times the human dose based on a mmol/m comparison) for 13 days during gestation. ProHance did not demonstrate genotoxic activity in bacterial reverse mutation assays using Salmonella typhimurium and Escherichia coli, in a mouse lymphoma forward mutation assay, in an in vitro cytogenetic assay measuring chromosomal aberration frequencies in Chinese hamster ovary cells, nor in an in vivo mouse micronucleus assay at intravenous doses up to 5.0 mmol/kg.

---

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Gadoteridol is one of the most stable gadolinium agents, theoretically making it one of the safer drugs to use during breastfeeding. Guidelines developed by several professional organizations state that breastfeeding need not be disrupted after a nursing mother receives a gadolinium-containing contrast medium. However, because there is no published experience with gadoteridol during breastfeeding, other agents may be preferred, especially while nursing a newborn or preterm infant.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

---

Protein Binding
It is unknown if protein binding of gadoteridol occurs in vivo.

---

Non-Human Toxicity Values
LD50 Mouse iv 11-14 mmol/kg /Gadoteridol injection/
LD50 Rat iv >10 mmol/kg /Gadoteridol injection/

[1]. The MRI contrast agent gadoteridol enhances distribution of rAAV1 in the rat hippocampus. Gene Ther. 2013 Dec;20(12):1172-7.

Gadoteridol is a macrocyclic nonionic gadolinium that provides contrast enhancement of the brain, spine, and surrounding tissues, resulting in improved visualization (compared with unenhanced MRI) of lesions with abnormal vascularity or those thought to disrupt the normal blood-brain barrier. It was 1 of the 3 macrocyclic gadolinium-based contrast agents (GBCAs) that was mandated by the EMA to replace linear gadolinium-based contrast agents due to concerns about retained gadolinium in the brain. Initially approved by the FDA in 1992, gadoteridol received additional approval in 2020 for use in pediatric patients less than 2 years old.
Gadoteridol is a Paramagnetic Contrast Agent. The mechanism of action of gadoteridol is as a Magnetic Resonance Contrast Activity.

---

Drug Indication
Gadoteridol is indicated for use with magnetic resonance imaging (MRI) in order to visualize lesions with disrupted blood-brain barrier and/or abnormal vascularity in the brain, spine, and associated tissues in adult and pediatric patients, including term neonates. It is also indicated for visualization of lesions in the head and neck in adult patients.
FDA Label

---

Mechanism of Action
Gadoteridol is a paramagnetic agent and, as such, develops a magnetic moment when placed in a magnetic field. The relatively large magnetic moment produced by the paramagnetic agent results in a relatively large local magnetic field, which can enhance the relaxation rates of water protons in the vicinity of the paramagnetic agent. In MRI, visualization of normal and pathologic brain tissue depends, in part, on variations in the radiofrequency signal intensity that occur with: 1) differences in proton density; 2) differences of the spinlattice or longitudinal relaxation times (T1); and 3) differences in the spin-spin or transverse relaxation time (T2). When placed in a magnetic field, gadoteridol decreases T1 relaxation times in the target tissues. At recommended doses, the effect is observed with greatest sensitivity in the T1-weighted sequences.

---

Therapeutic Uses
Contrast Media
ProHance (Gadoteridol) Injection is indicated for use in MRI in adults and children over 2 years of age to visualize lesions with abnormal vascularity in the brain (intracranial lesions), spine and associated tissues. /Included in US product label/
ProHance is indicated for use in MRI in adults to visualize lesions in the head and neck. /Included in US product label/

---

Drug Warnings
/BOXED WARNING/ WARNING: NEPHROGENIC SYSTEMIC FIBROSIS. Gadolinium-based contrast agents (GBCAs) increase the risk for nephrogenic systemic fibrosis (NSF) among patients with impaired elimination of the drugs. Avoid use of GBCAs in these patients unless the diagnostic information is essential and not available with non-contrasted MRI or other modalities. NSF may result in fatal or debilitating systemic fibrosis affecting the skin, muscle and internal organs. The risk for NSF appears highest among patients with: chronic, severe kidney disease (GFR <30 mL/min/1.73 sq m), or acute kidney injury. Screen patients for acute kidney injury and other conditions that may reduce renal function. For patients at risk for chronically reduced renal function (e.g. age > 60 years, hypertension or diabetes), estimate the glomerular filtration rate (GFR) through laboratory testing. For patients at highest risk for NSF, do not exceed the recommended ProHance dose and allow a sufficient period of time for elimination of the drug from the body prior to re-administration.
Gadolinium-based contrast agents (GBCAs) increase the risk for nephrogenic systemic fibrosis (NSF) among patients with impaired elimination of the drugs. Avoid use of GBCAs among these patients unless the diagnostic information is essential and not available with non-contrast enhanced MRI or other modalities. The GBCA-associated NSF risk appears highest for patients with chronic, severe kidney disease (GFR <30 mL/min/1.73 sq m) as well as patients with acute kidney injury. The risk appears lower for patients with chronic, moderate kidney disease (GFR 30-59 mL/min/1.73 sq m) and little, if any, for patients with chronic, mild kidney disease (GFR 60-89 mL/min/1.73 sq m). NSF may result in fatal or debilitating fibrosis affecting the skin, muscle and internal organs. ... Screen patients for acute kidney injury and other conditions that may reduce renal function. Features of acute kidney injury consist of rapid (over hours to days) and usually reversible decrease in kidney function, commonly in the setting of surgery, severe infection, injury or drug-induced kidney toxicity. Serum creatinine levels and estimated GFR may not reliably assess renal function in the setting of acute kidney injury. For patients at risk for chronically reduced renal function (e.g., age > 60 years, diabetes mellitus or chronic hypertension), estimate the GFR through laboratory testing. Among the factors that may increase the risk for NSF are repeated or higher than recommended doses of a GBCA and the degree of renal impairment at the time of exposure. Record the specific GBCA and the dose administered to a patient. For patients at highest risk for NSF, do not exceed the recommended ProHance dose and allow a sufficient period of time for elimination of the drug prior to re-administration. For patients receiving hemodialysis, physicians may consider the prompt initiation of hemodialysis following the administration of a GBCA in order to enhance the contrast agent's elimination. The usefulness of hemodialysis in the prevention of NSF is unknown
The possibility of a reaction, including serious, life threatening, or fatal, anaphylactic or cardiovascular reactions, or other idiosyncratic reactions, should always be considered, especially in those patients with a history of a known clinical hypersensitivity or a history of asthma or other allergic respiratory disorders.
FDA Pregnancy Risk Category: C /RISK CANNOT BE RULED OUT. Adequate, well controlled human studies are lacking, and animal studies have shown risk to the fetus or are lacking as well. There is a chance of fetal harm if the drug is given during pregnancy; but the potential benefits may outweigh the potential risk./
For more Drug Warnings (Complete) data for GADOTERIDOL (19 total), please visit the HSDB record page.

---

Pharmacodynamics
Gadoteridol affects proton relaxation times and consequently the MR signal. Signal intensity is affected by the dose and relaxivity of the gadoteridol molecule. Consistently, for all gadolinium-based contrast agents, the relaxivity of gadoteridol decreases with the increase of the magnetic field strength used in clinical MRI (0.2 –3.0T). Disruption of the blood-brain barrier or abnormal vascularity allows the accumulation of gadoteridol in lesions such as neoplasms, abscesses, and subacute infarcts. The pharmacokinetics of gadoteridol in various lesions is not known.

C₁₇H₂₈GDN₄O₇

557.68

558.12

120066-54-8

Gadoteridol pentahydrate

60714

White to off-white solid powder

668.2ºC at 760 mmHg

>225ºC

357.9ºC

1.04E-20mmHg at 25°C

1

11

5

29

471

0

DPNNNPAKRZOSMO-UHFFFAOYSA-K

InChI=1S/C17H32N4O7.Gd/c1-14(22)10-18-2-4-19(11-15(23)24)6-8-21(13-17(27)28)9-7-20(5-3-18)12-16(25)26;/h14,22H,2-13H2,1H3,(H,23,24)(H,25,26)(H,27,28);/q;+3/p-3

2-[4,7-bis(carboxylatomethyl)-10-(2-hydroxypropyl)-1,4,7,10-tetrazacyclododec-1-yl]acetate;gadolinium(3+)

SQ-32692SQ32692 Gd-HP-DO3A

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ≥ 280 mg/mL (~502.08 mM)
DMSO :< 1 mg/mL

Solubility in Formulation 1: 100 mg/mL (179.31 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

---

 (Please use freshly prepared in vivo formulations for optimal results.)