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

Absorption, Distribution and Excretion
Radiographic contrast media (CM) induce renal vasoconstriction and may initiate induced nephropathy. Endothelin (ET), a vasoconstrictor, and nitric oxide (NO), a vasodilator, which are synthesized in the kidney by the vascular endothelium as well as by tubular epithelial and glomerular mesangial cells, are key modulators of renal circulation after CM administration. Intravascular CM, in addition, induces pronounced diuresis and natriuresis. The aim of the present study was to evaluate and compare changes in endogenous vasoactive mediators and contrast-induced natriuresis after CM administration. Diagnostic angiographic procedures were performed in 14 patients (9 males and 5 females) using the non-ionic CM Iopamidol. Before and immediately after angiography, venous blood and urine samples were obtained. The urinary excretion of ET-1 and nitrates/nitrites (NOx), and the fractional excretion of sodium (FENa) were measured and analyzed. The urinary excretion of both ET-1 and NOx increased significantly (p < 0.05) after angiography, and urinary ET-1 and NOx excretion was correlated with an increase in FENa (p < 0.05). Exposure to CM in humans is associated with an increase in urinary ET and NOx. The excretion of sodium following CM administration is associated with an increase in urinary ET and NOx. ET and NO might be important in the renal change in humans after CM administration.
No iodinated compound other than Iopamidol was found in the urine of subjects who received intrathecal injection of 10 mL of Iopamiro "300". The compound was neither metabolized nor altered in its optical configuration and urinary iodide content was always in the normal range. Between 72 and 85% of injected Iopamidol was excreted within 72 h of injection.
It is not known whether this drug is excreted in human milk.
The pharmacokinetics of iopamidol in both normal and abnormal tissue have been shown to be variable. Contrast enhancement appears to be greatest soon after administration of the contrast medium, and following intraarterial rather than intravenous administration. ...
For more Absorption, Distribution and Excretion (Complete) data for Iopamidol (8 total), please visit the HSDB record page.

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

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Biological Half-Life
The pharmacokinetics of iopamidol 370 (Iopamiro), a non-ionic water soluble organic iodine compound, were studied in adults with different degrees of chronic renal failure and in healthy volunteers. After 50 mL were administered i.v., plasma and urine levels were determined. The main pharmacokinetic parameters were calculated on the basis of bi-compartmental open model. There were significant differences from healthy volunteers in half-life beta, which increased with the degree of renal failure as the clearance values decreased. Half-life beta was equal to 1.67 h in healthy volunteers, 4.24 h in patients with mild renal failure and 10.03 h in patients with severe renal failure. The clearance decreased as follows: 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. No significant differences were found in distribution volume values nor in half-life alpha.
The pharmacokinetics of intravenously administered iopamidol in normal subjects conform to an open two-compartment model with first order elimination (a rapid alpha phase for drug distribution and a slow beta phase for drug elimination). The elimination serum or plasma half-life is approximately two hours; the half-life is not dose dependent.

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Intravenous iodinated contrast media are poorly excreted into breastmilk and poorly absorbed orally so they are not likely to reach the bloodstream of the infant or cause any adverse effects in breastfed infants. Guidelines developed by several professional organizations state that breastfeeding need not be disrupted after a nursing mother receives an iodine-containing contrast medium. However, because there is no published experience with iopamidol 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.

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Interactions
To determine if depression of creatinine clearance after administration of contrast medium may be prevented with theophylline. A nonionic, low-osmolality contrast medium (iopamidol) or an ionic, high-osmolality contrast medium (sodium diatrizoate) was administered to 93 patients. Before the examination, these patients were given theophylline or a placebo orally. There were also 30 patients who received an adenosine-uptake inhibitor (dipyridamole). Creatinine clearance and urinary adenosine levels were measured before and after angiography. Creatinine clearance decreased 18% +/- 4 in the placebo-iopamidol group but did not decrease in the theophylline group; urinary adenosine increased 67% +/- 7. Creatinine clearance decreased 42% +/- 5 in the placebo-sodium diatrizoate group and decreased 24% +/- 3 in the theophylline group; urinary adenosine increased 119% +/- 8. In the dipyridamole group in which iopamidol was given, urinary adenosine increased 96% +/- 7 and creatinine clearance decreased 37% +/- 5. Intrarenal adenosine can be implicated in the pathogenesis of hypertonic contrast medium nephrotoxicity.
Complete thrombotic occlusion of the arterial blood flow in the upper extremity was produced after mixture of Isovue 370 (iopamidol) and papaverine hydrochloride during routine angiography. Bolus and then continuous infusion of urokinase failed to dissolve the thrombus. The patient required a surgical thrombectomy and recovered uneventfully. This case report demonstrates that caution should be exercised when Isovue 370 and papaverine are used in angiography.
Intrathecal administration of corticosteroids with iopamidol is contraindicated.[US Natl Inst Health; DailyMed. Current Medication Information for ISOVUE-M (iopamidol) injection, solution
In vitro studies with animal blood showed that many radiopaque contrast agents, including iopamidol, produced a slight depression of plasma coagulation factors including prothrombin time, partial thromboplastin time, and fibrinogen, as well as a slight tendency to cause platelet and/or red blood cell aggregation. Transitory changes may occur in red cell and leucocyte counts, serum calcium, serum creatinine, serum glutamic oxaloacetic transaminase (SGOT), and uric acid in urine; transient albuminuria may occur.
Renal toxicity has been reported in a few patients with liver dysfunction who were given oral cholecystographic agents followed by intravascular contrast agents. Administration of intravascular agents should therefore be postponed in any patient with a known or suspected hepatic or biliary disorder who has recently received a cholecystographic contrast agent.

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Non-Human Toxicity Values
LD50 Rat intraarterial 13,268 mg/kg
LD50 Rat intravenous 22,044 mg/kg
LD50 Mouse intracerebral 3 g/kg
LD50 Mouse intravenous 33 g/kg
For more Non-Human Toxicity Values (Complete) data for Iopamidol (8 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 benzenedicarboxamide compound having N-substituted carbamoyl groups at the 1- and 3-positions, iodo substituents at the 2-, 4- and 6-positions and a (2S)-2-hydroxypropanamido group at the 5-position. It has a role as a radioopaque medium, an environmental contaminant and a xenobiotic. It is a benzenedicarboxamide, an organoiodine compound and a pentol.
Iopamidol is a contrast agent developed by Bracco with nonionic, low-osmolar properties.
Iopamidol is a Radiographic Contrast Agent. The mechanism of action of iopamidol is as a X-Ray Contrast Activity.
Iopamidol is an organic iodine compound and used as a non-ionic water soluble radiographic contrast medium. Iopamidol blocks x-rays as they pass through the body, thereby allowing body structures not containing iodine to be visualized. The degree of opacity produced by iopamidol is directly proportional to the total amount of the iodinated contrast agent in the path of the x-rays. The visualization of body structures is dependent upon the distribution and elimination of iopamidol. (NCI05)
A non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiological procedures.
See also: Iohexol (annotation moved to).

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Drug Indication
FDA Label

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Mechanism of Action
To test the hypothesis that iodinated contrast media may induce an elevation in serum potassium level, /contrast media was administered to rabbits and tested in-vitro according to four protocols./ Protocol A: After intravenous infusion of contrast media into six rabbits, alterations of potassium ion concentrations were measured. Protocol B: Fresh rabbit blood was mixed in vitro with contrast media, and the fluctuations in potassium were monitored over a 30-minute period. Protocol C: Similar to protocol B, except that blood from humans with no reaction to contrast media was used. For protocol A, blood potassium levels increased above baseline levels. The elevations were statistically significant (P < .05). For protocol B, diatrizoate and ioxaglate caused a gradual increase in blood potassium levels, but iopamidol did not. In protocol C, all three contrast media caused statistically significant elevation in potassium levels. The release of potassium was statistically significant at 5 minutes (P < .05 for diatrizoate and ioxaglate, and P < .01 for iopamidol). The mean release rates (+/- standard deviation) by means of linear regression analysis were 0.0190 mmol/min +/- 0.0112 with diatrizoate, 0.0159 mmol/min +/- 0.0057 with iopamidol, and 0.0088 mmol/min +/- 0.0033 with ioxaglate. Iodinated contrast media increase blood potassium levels causing release of potassium into intravascular spaces. This potassium release may play some role in contrast medium-induced adverse reactions.
The synthesis of prostaglandins and other metabolic products of arachidonic acid (AA) was investigated in isolated perfused lungs of hamsters during the infusion of various concentrations of meglumine diatrizoate and iopamidol. Forty nmol of (14)C-AA was infused into the pulmonary circulation with radiographic contrast media (RCM), and prostaglandins, thromboxanes, and metabolites of lipoxygenases were analyzed from the nonrecirculating perfusion effluent. Arachidonate infusion increased the perfusion pressure. This pressor response was decreased by iopamidol ... The amount of radioactivity was decreased in the perfusion effluent and increased in lung lipids by iopamidol. ... Almost all arachidonate metabolites were decreased significantly by iopamidol when compared with hypertonic saline ...

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Therapeutic Uses
/EXPERIMENTAL THER:/ Meconium obstruction of prematurity (MO) often occurs in extremely low-birth weight (ELBW) infants, and its treatment is quite a challenge for neonatologists. /Investigators/ attempted to establish a method of primary treatment for MO of prematurity in ELBW infants. An iopamidol enema with 50 cm H2O static pressure was performed as the primary treatment. This procedure is safe and effective and /was recommended/ as the first treatment for MO in ELBW infants. The procedure was performed 50 times in 23 infants and no complications occurred. Out of 23 patients, 20 (88%) improved, but the other 3 did not. In the failure group, the procedure was performed on a significantly later date and the mortality rate was higher (12.5 vs. 67%). This procedure is safe and effective. /The authors/ recommend this as the first treatment for MO in ELBW infants.
/EXPERIMENTAL THER:/ ... Ninety mice used in this study were divided into three groups: lipiodol, iopamidol, and normal saline. The test compounds were given by submucosal injection to the gastric wall of anesthetized mice. The specimens were subjected to histopathological examination. The mean grades of acute inflammatory response after iopamidol and lipiodol injection were significantly higher than control group. However, there was no significant difference between iopamidol and lipiodol injection. The mean grade of chronic inflammatory response and fibrosis showed no differences between groups. The presence or absence of fibrinoid necrosis and mesothelial hyperplasia showed no statistical differences at each time point between groups. The foam cell, which is similar to human signet ring cell carcinoma, were not identified in normal saline and iopamidol group, but were detected by postoperative day 7 in lipiodol group. /It was concluded/ that iopamidol and lipiodol when used as a contrast media of CT lymphography is an available material for preoperative sentinel node navigation surgery for gastric cancer with an acceptable incidence of pathological alterations in a mouse model. /The/ results are potentially useful to clinical (human) application.
Hematomas and intraparenchymal bleeders seldom demonstrate any contrast enhancement. However, in cases of intraparenchymal clot, for which there is no obvious clinical explanation, contrast media administration may be helpful in ruling out the possibility of associated arteriovenous malformation. /Included in US product label/
Arteriovenous malformations and aneurysms will show contrast enhancement. For these vascular lesions, the enhancement is probably dependent on the iodine content of the circulating blood pool. /Included in US product label/
For more Therapeutic Uses (Complete) data for Iopamidol (9 total), please visit the HSDB record page.

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Drug Warnings
Focal and generalized motor seizures have been reported after intrathecal use of water-soluble contrast agents including iopamidol. In several of those cases reported with iopamidol, higher than recommended doses were employed. Therefore avoid: deviations from recommended neuroradiologic procedure or patient management; use in patients with a history of epilepsy unless medically justified; overdosage; intracranial entry of a bolus or premature diffusion of a high concentration of the medium; failure to maintain elevation of the head during the procedure, on the stretcher, and in bed; excessive and particularly active patient movement or straining.[US Natl Inst Health; DailyMed. Current Medication Information for ISOVUE-M (iopamidol) injection, solution
FDA Pregnancy risk category B: NO EVIDENCE OF RISK IN HUMANS. Adequate, well controlled studies in pregnant women have not shown increased risk of fetal abnormalities despite adverse findings in animals, or, in the absents of adequate human studies, animal studies show no fetal risk. The chance of fetal harm is remote but remains a possibility.
Use of medications that may lower the seizure threshold (phenothiazine derivatives, including those used for their antihistaminic properties; tricyclic antidepressants; MAO inhibitors; CNS stimulants; analeptics; antipsychotic agents) should be carefully evaluated. While the contributory role of such medications has not been established, some physicians have discontinued these agents at least 48 hours before and for at least 24 hours following intrathecal use.[US Natl Inst Health; DailyMed. Current Medication Information for ISOVUE-M (iopamidol) injection, solution
Direct intracisternal or ventricular administration for standard radiography (without computerized tomographic enhancement) is not recommended. Inadvertent intracranial entry of a large or concentrated bolus of the contrast medium, which increases the risk of neurotoxicity, can be prevented by careful patient management. Also, effort should be directed to avoid rapid dispersion of the medium causing inadvertent rise to intracranial levels (e.g., by active patient movement). If such intracranial entry of the medium occurs, prophylactic anticonvulsant treatment with diazepam or barbiturates orally for 24 to 48 hours should be considered.[US Natl Inst Health; DailyMed. Current Medication Information for ISOVUE-M (iopamidol) injection, solution
For more Drug Warnings (Complete) data for Iopamidol (37 total), please visit the HSDB record 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.)