Renal pH mapping can be performed using imipamidol, a responsive MRI chemical exchange saturation transfer contrast agent [1].

Absorption, Distribution and Excretion
Contrast agents (CMs) can cause renal vasoconstriction and may induce nephropathy. Endothelin (ET), a vasoconstrictor, and nitric oxide (NO), a vasodilator, are synthesized by renal vascular endothelial cells, renal tubular epithelial cells, and glomerular mesangial cells, and are key regulators of renal circulation after CM administration. Furthermore, intravascular CMs also induce significant diuresis and sodium excretion. This study aimed to assess and compare changes in endogenous vasoactive mediators and contrast agent-induced sodium excretion after CM administration. Diagnostic angiography was performed on 14 patients (9 men and 5 women) using the non-ionic contrast agent iopamidol. Venous blood and urine samples were collected immediately before and after angiography. This study measured and analyzed the excretion of endothelin-1 (ET-1) and nitrate/nitrite (NOx) in urine, as well as the fractional sodium excretion (FENa). Following angiography, urinary excretion of both ET-1 and NOx significantly increased (p < 0.05), and this excretion was positively correlated with an increase in FENa (p < 0.05). Human exposure to contrast agents (CM) was associated with increased urinary ET and NOx. Sodium excretion following CM administration was also associated with increased urinary ET and NOx. ET and NO may play important roles in changes in the human kidneys following CM administration. In the urine of subjects who received an intrathecal injection of 10 mL iopamidol "300", no other iodinated compounds were detected besides iopamidol. This compound did not undergo metabolism, its optical configuration remained unchanged, and urinary iodine levels remained within the normal range. 72% to 85% of the injected iopamidol was excreted within 72 hours after injection. It is unclear whether this drug is secreted into human breast milk.
The pharmacokinetics of iopamirol in both normal and abnormal tissues showed individual variability. Contrast enhancement appeared to be most pronounced shortly after contrast agent injection, and intra-arterial injection was more effective than intravenous injection. ...
For more complete data on the absorption, distribution, and excretion of iopamirol (8 types), please visit the HSDB record page.

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Metabolism/Metabolites
No significant metabolism, deiodination, or biotransformation occurred.

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Biological Half-Life
This study investigated the pharmacokinetics of iopamirol 370 (Iopamiro, a nonionic, water-soluble organic iodine compound) in adult patients with varying degrees of chronic renal failure and healthy volunteers. Plasma and urinary drug concentrations were measured after 50 mL intravenous injection. Major pharmacokinetic parameters were calculated based on a two-compartment open model. The β-half-life differed significantly in patients with chronic renal failure compared to healthy volunteers, and clearance decreased and the β-half-life prolonged with increasing severity of renal failure. The β-half-life was 1.67 hours in healthy volunteers, 4.24 hours in patients with mild renal failure, and 10.03 hours in patients with severe renal failure. Clearance decreased sequentially: 0.11 L/h/kg in healthy volunteers, 0.06 L/h/kg in patients with mild renal failure, and 0.02 L/h/kg in patients with severe renal failure. There were no significant differences in volume of distribution or α-half-life. The pharmacokinetics of iopamidol administered intravenously in normal subjects conformed to an open two-compartment model of first-order elimination (rapid α-phase distribution and slow β-phase elimination). The serum or plasma elimination half-life was approximately 2 hours and was dose-independent.

Effects During Pregnancy and Lactation
◉ Overview of Medication Use During Lactation
Very little iodine contrast agents administered intravenously are excreted into breast milk, and their oral absorption rate is also very low. Therefore, they are unlikely to enter the infant's bloodstream and will not cause any adverse effects on breastfed infants. Guidelines developed by multiple professional organizations indicate that breastfeeding mothers do not need to interrupt breastfeeding after receiving iodine-containing contrast agents. However, since there is currently no published experience regarding the use of iopamidol during lactation, other medications may be preferred, especially when breastfeeding newborns or premature infants. ◉ Effects on Breastfed Infants
No relevant published information was found as of the revision date. ◉ Effects on Lactation and Breast Milk
No relevant published information was found as of the revision date.

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Interaction
To determine whether theophylline could prevent a decrease in creatinine clearance after contrast agent injection, we administered either a non-ionic hypotonic contrast agent (iopamidol) or an ionic hypertonic contrast agent (sodium pantothenate) to 93 patients. Prior to the examination, these patients received oral theophylline or a placebo. Additionally, 30 patients received an adenosine uptake inhibitor (dipyridamole). Creatinine clearance and urinary adenosine levels were measured before and after angiography. In the placebo-iopamidol group, creatinine clearance decreased by 18% ± 4%, while in the theophylline group, creatinine clearance did not decrease; urinary adenosine levels increased by 67% ± 7%. In the placebo-sodium iodokoronate group, creatinine clearance decreased by 42% ± 5%, and in the theophylline group, it decreased by 24% ± 3%. Urinary adenosine levels increased by 119% ± 8%. In the dipyridamole group receiving iopamidol, urinary adenosine levels increased by 96% ± 7, and creatinine clearance decreased by 37% ± 5. Intrarenal adenosine may be involved in the pathogenesis of hyperosmolar contrast agent nephrotoxicity.
During routine angiography, the use of a mixture of Isovue 370 (iophanate-methyl) and papaverine hydrochloride resulted in complete thrombosis of the upper extremity arterial blood flow. Rapid intravenous injection and continuous intravenous infusion of urokinase failed to dissolve the thrombus. The patient underwent surgical thrombectomy and recovered well postoperatively. This case report demonstrates the need for caution when using Isovue 370 and papaverine in angiography.
Intrathecal corticosteroids in combination with iopamidol are contraindicated. [National Institutes of Health; DailyMed. Latest information on ISOVUE-M (iophanate-methyl) injection]
In vitro animal blood studies have shown that many radiopaque contrast agents, including iopamidol, can cause a slight decrease in plasma clotting factors (including prothrombin time, partial thromboplastin time, and fibrinogen) and a slight tendency for platelet and/or erythrocyte aggregation. Transient changes may occur in red blood cell and white blood cell counts, serum calcium, serum creatinine, serum aspartate aminotransferase (SGOT), and uric acid levels; transient proteinuria may occur.
A small number of patients with hepatic impairment have been reported to experience nephrotoxicity when receiving intravascular contrast agents after oral cholecystography. Therefore, intravascular contrast agents should be postponed in patients who have recently received cholecystography and have known or suspected hepatobiliary disease.
Non-human toxicity values

Rat arterial LD50: 13,268 mg/kg
Rat intravenous LD50: 22,044 mg/kg
Mouse brain LD50: 3 g/kg
Mouse intravenous LD50: 33 g/kg
For more non-human toxicity values (complete data) for iopamidol (8 items in total), please visit the HSDB record page.

[1]. Iopamidol as a responsive MRI-chemical exchange saturation transfer contrast agent for pH mapping of kidneys: In vivo studies in mice at 7 T. Magn Reson Med. 2011 Jan;65(1):202-11.

Iopamidol is a phthalamide compound with N-substituted carbamoyl groups at positions 1 and 3, iodine substituents at positions 2, 4, and 6, and a (2S)-2-hydroxypropionamide group at position 5. It can be used as a radioactive contrast agent, an environmental pollutant, and an exogenous substance. It is a phthalamide compound, an organoiodine compound, and a pentanol compound. Iopamidol is a non-ionic, hypotonic contrast agent developed by Braco. Iopamidol is a radioactive contrast agent. Its mechanism of action is as an X-ray contrast agent. Iopamidol is an organoiodine compound used as a non-ionic, water-soluble radioactive contrast agent. Iopamidol blocks X-rays from passing through the human body, thus allowing the visualization of iodine-free human tissues. The degree of visualization produced by iopamidol is proportional to the total amount of iodinated contrast agent in the X-ray path. The visualization of human tissues depends on the distribution and clearance of iopamidol. (NCI05)
A nonionic, water-soluble contrast agent for use in myelography, arthrography, renal angiography, arteriography, and other radiological examinations.
See also: Iohexol (note moved to).
Pharmaceutical Indications
>
FDA Label
Mechanism of Action
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To verify the hypothesis that iodinated contrast agents may lead to elevated serum potassium levels, we administered and tested the contrast agent in rabbits using four protocols. Protocol A: Changes in potassium ion concentration were measured after intravenous infusion of the contrast agent in six rabbits. Protocol B: Fresh rabbit blood was mixed with the contrast agent in vitro, and fluctuations in potassium ion levels were monitored over 30 minutes. Protocol C: Similar to Protocol B, except that human blood unresponsive to the contrast agent was used. In Protocol A, serum potassium levels were higher than baseline. The increase in serum potassium levels was statistically significant (P < 0.05). In Protocol B, iohexol and sodium iodosargase led to a gradual increase in serum potassium levels, while iopamidol had no such effect. In Protocol C, all three contrast agents significantly increased serum potassium levels. At 5 minutes, potassium release was statistically significant (iohexol and iodosagarate sodium P < 0.05, iopamidol P < 0.01). Linear regression analysis showed the mean release rates (± standard deviation) as follows: iohexol 0.0190 mmol/min ± 0.0112, iopamidol 0.0159 mmol/min ± 0.0057, and iodosagarate sodium 0.0088 mmol/min ± 0.0033. Iodinated contrast agents can increase serum potassium levels, leading to potassium release into the bloodstream. Potassium release may play a role in adverse reactions caused by contrast agents. This study investigated the synthesis of prostaglandins and other arachidonic acid (AA) metabolites in isolated hamster lungs by infusing different concentrations of iodinated dimethoprim and iopamidol. 40 nmol of 14C-AA was perfused into the pulmonary circulation along with a radiocontrast agent (RCM), and the metabolites of prostaglandins, thromboxanes, and lipoxygenases were analyzed from the non-circulating perfusion effluent. Arachidonic acid infusion increased perfusion pressure. Iopamidol reduced this pressor response… Iopamidol reduced radioactivity in the perfusion effluent and increased radioactivity in pulmonary lipids. Compared to hypertonic saline, iopamidol significantly reduced almost all arachidonic acid metabolites…

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Therapeutic Use
/Experimental Treatment:/ Meconium obstruction (MO) in preterm infants is common in very low birth weight (ELBW) infants, and its treatment presents a considerable challenge for neonatologists. /Researchers/ attempted to establish a first-line treatment for meconium obstruction in ELBW infants. Iopamidol enema with a hydrostatic pressure of 50 cm H2O was used as a first-line treatment. This method is safe and effective and /recommended/ as a first-line treatment for meconium obstruction in ELBW infants. This treatment was performed 50 times in 23 infants without complications. Of the 23 patients, 20 (88%) showed improvement, while the remaining 3 did not. In the failure group, the operation time was significantly delayed, and the mortality rate was also higher (12.5% vs. 67%). The procedure was safe and effective. /Authors/ recommend it as a first-line treatment for submucosal gastric hemorrhage in very low birth weight infants.
/Experimental Treatment:/...This study used 90 mice, divided into three groups: iodized oil group, iopamidol group, and saline group. The test compound was administered submucosally to the stomach wall of anesthetized mice. Histopathological examination of the specimens was performed. The mean grade of acute inflammatory response after injection was significantly higher in the iopamidol group and the iodized oil group than in the control group. However, there was no significant difference between the iopamidol group and the iodized oil group. There was no difference in the mean grade of chronic inflammatory response and fibrosis among the groups. There were no statistically significant differences in the presence or absence of fibrinoid necrosis and mesothelial hyperplasia among the groups at each time point. Foam cells, similar to human signet ring cell carcinoma, were not detected in the saline and iopamidol groups, but were detected in the iodized oil group on postoperative day 7. /Conclusion/ Iopamidol and iodized oil, as contrast agents for CT lymphangiography, can be used in preoperative sentinel lymph node navigation surgery for gastric cancer, with an acceptable incidence of pathological changes in a mouse model. /These/ results may have potential value for clinical (human) applications.
Contrast enhancement is rarely seen in hematomas and intraparenchymal hemorrhage. However, for intraparenchymal thrombosis without a clear clinical explanation, the use of contrast agents may help rule out the possibility of associated arteriovenous malformations. /Included in US Product Label/
Arteriovenous malformations and aneurysms show contrast enhancement. For these vascular lesions, the degree of enhancement may depend on the iodine content in the circulating blood pool. /Included in US Product Label/
For more complete data on the therapeutic uses of iopamidol (out of 9), please visit the HSDB record page.

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Drug Warning
Focused and generalized motor seizures have been reported following intrathecal injection of water-soluble contrast agents (including iopamidol). In some iopamidol cases, doses higher than recommended have been used. Therefore, the following should be avoided: deviation from recommended neuroradiological procedures or patient management; use in patients with a history of epilepsy unless medically indicated; overdose; intracranial injection of the drug or premature diffusion of high-concentration contrast agents; failure to maintain head elevation during procedures, on stretchers, and while in bed; excessive patient activity or exertion. [National Institutes of Health; DailyMed. Latest information on ISOVUE-M (iopamidol) injection]
FDA Pregnancy Risk Classification B: No evidence of risk in humans. Although adverse reactions have been observed in animal studies, adequate, well-controlled studies in pregnant women have not shown an increased risk of fetal malformations; or, in the absence of adequate human studies, animal studies have shown no fetal risk. The possibility of fetal harm is small but still exists.
The use of medications that may lower the seizure threshold (phenothiazine derivatives, including those with antihistamine properties; tricyclic antidepressants; monoamine oxidase inhibitors; central nervous system stimulants; stimulants; antipsychotics) should be carefully evaluated. While the pathogenic effects of these medications have not been established, some physicians have discontinued them at least 48 hours before and at least 24 hours after intrathecal injection. [National Institutes of Health; DailyMed. Latest information on ISOVUE-M (iophanate-methyl) injection]
Direct injection of iopamidol into the cistern or ventricles for standard radiographic examination (without contrast-enhanced computed tomography) is not recommended. Careful patient management can prevent the accidental entry of large or high concentrations of contrast agent into the intracranial space, which increases the risk of neurotoxicity. Furthermore, efforts should be made to avoid rapid diffusion of the contrast agent leading to its accidental rise into the intracranial space (e.g., due to patient activity). If intracranial entry of contrast agent occurs, prophylactic anticonvulsant therapy with oral diazepam or barbiturates for 24 to 48 hours should be considered. [National Institutes of Health; DailyMed. Latest medication information for ISOVUE-M (iophanate-methyl) injection
For more complete data on drug warnings for iopamidol (37 in total), please visit the HSDB records page.]

C17H22I3N3O8

777.0894

776.854

60166-93-0

Iopamidol-d8;1795778-90-3

65492

White to off-white solid powder

2.3±0.1 g/cm3

785.3±60.0 °C at 760 mmHg

>320ºC (dec)

428.8±32.9 °C

0.0±2.9 mmHg at 25°C

1.739

-2.09

8

8

10

31

583

1

C[C@@H](C(=O)NC1=C(C(=C(C(=C1I)C(=O)NC(CO)CO)I)C(=O)NC(CO)CO)I)O

XQZXYNRDCRIARQ-LURJTMIESA-N

InChI=1S/C17H22I3N3O8/c1-6(28)15(29)23-14-12(19)9(16(30)21-7(2-24)3-25)11(18)10(13(14)20)17(31)22-8(4-26)5-27/h6-8,24-28H,2-5H2,1H3,(H,21,30)(H,22,31)(H,23,29)/t6-/m0/s1

(S)-N1,N3-bis(1,3-dihydroxypropan-2-yl)-5-(2-hydroxypropanamido)-2,4,6-triiodoisophthalamide

SQ-13396 B 15000Gastromiro B15000IopamidolSQ13396GastromiroB-15000IsovueSQ 13396Niopam

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

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

H2O : ~100 mg/mL (~128.69 mM)
DMSO : ~50 mg/mL (~64.34 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (2.68 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.08 mg/mL (2.68 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.08 mg/mL (2.68 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 110 mg/mL (141.55 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.

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