GASTROGRAFIN

Indications

• Intravenous pyelography
• Angiography

Mechanism of action

Diatrizoate acts as a radiopaque agent by containing high levels of iodine, which is electron-dense and capable of scattering or stopping X-rays. When introduced into the body, it accumulates in targeted areas, increasing the contrast between different tissues on X-ray images. This accumulation allows for clearer visualization of organs and other structures during diagnostic imaging procedures. The mechanism also involves potential nephrotoxic effects, as iodinated contrast media can reduce renal blood flow and directly affect renal tubular epithelial cells, leading to acute renal failure in susceptible individuals.

Pharmacodynamics

As a radiopaque medium, diatrizoate enhances the contrast in X-ray imaging by localizing in specific tissues and blocking X-rays due to its iodine content. This property allows for the visualization of abnormalities or conditions within organs, aiding in the diagnosis of various medical issues. The contrast effect is particularly useful in identifying issues in the vascular system, gastrointestinal tract, and urinary system. However, attention must be given to potential nephrotoxic effects, especially in patients with pre-existing renal impairment.

Pharmacokinetics

Diatrizoate is administered primarily via intravenous injection, leading to rapid distribution throughout the vascular system. It is excreted unchanged by the kidneys, primarily through glomerular filtration. The onset of action is immediate, with peak concentrations typically occurring shortly after administration. The elimination half-life is relatively short, and the contrast medium is cleared from the body within hours post-administration. Care must be taken in patients with compromised renal function, as the nephrotoxic potential may lead to acute kidney injury.

Adverse effects

• Nausea
• Vomiting
• Hypersensitivity reactions
• Nephrotoxicity
• Thyroid dysfunction
• Injection site reactions

Precautions

• Assess renal function prior to use, especially in patients with pre-existing renal impairment
• Monitor hydration status and consider prehydration in at-risk patients
• Use cautiously in patients with a history of asthma or allergic reactions

Pregnancy

Diatrizoate should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus, as iodine can affect fetal thyroid function.

Breast-feeding

It is generally considered safe to use diatrizoate during breastfeeding, but nursing mothers should be advised to monitor for any adverse effects in their infants.

Storage

Store at room temperature, protected from light. Do not freeze.

Formulations

• Injection solution

Indications

• Used as a solubilizing agent in pharmaceutical preparations
• Used in radiographic contrast media formulations

Dosage

Children: Refer to specific formulations for paediatric dosing instructions as it varies depending on the application.

Adults: Refer to specific formulations for adult dosing instructions as it varies depending on the application.

Mechanism of action

Meglumine acts by enhancing the solubility and stability of drugs in solution, particularly in radiographic contrast agents. It is involved in purinergic signaling pathways, which are essential for various physiological processes, including neurotransmission and inflammation.

Pharmacodynamics

The pharmacodynamic profile of meglumine is largely influenced by its role as a solubilizing agent. It does not exhibit direct pharmacological effects on its own but rather facilitates the action of other active ingredients in formulations. Its impact on purinergic signaling may contribute to modulating physiological responses in the body.

Pharmacokinetics

Meglumine is rapidly absorbed when administered, with its pharmacokinetics closely tied to the properties of the drugs it accompanies. The distribution, metabolism, and excretion of meglumine are not well-defined as it typically functions as an excipient rather than an active therapeutic agent. Its elimination from the body is primarily via renal pathways.

Pregnancy

There is insufficient data on the use of meglumine in pregnancy, therefore it should only be used if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Caution is advised when administering meglumine to breastfeeding women, as its effects on infants are not well studied.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Mechanism of action

Diatrizoate is an iodine-containing X-ray contrast agent. Iodated contrast agents were among the first contrast agents developed. Iodine is known to be particular electron-dense and to effectively scatter or stop X-rays. A good contrast agent requires a high density of electron-dense atoms. Therefore, the more iodine, the more "dense" the x-ray effect. Iodine based contrast media are water soluble and harmless to the body. These contrast agents are sold as clear colorless water solutions, the concentration is usually expressed as mg I/ml. Modern iodinated contrast agents can be used almost anywhere in the body. Most often they are used intravenously, but for various purposes they can also be used intraarterially, intrathecally (the spine) and intraabdominally - just about any body cavity or potential space. Radiocontrast medium induced nephrotoxicity is a major clinical problem. There is considerable interest in reducing the incidence of acute renal failure due to the use of radiocontrast media (RCM). Reduction of renal blood flow and direct toxic effect on renal tubular epithelial cells have been postulated as major causes of RCM nephropathy. Understanding the molecular mechanisms by which RCM cause cell damage may allow the development of pharmacological therapy to prevent their nephrotoxicity. In this work we have investigated the signaling pathways that may be affected by RCM. The incubation of human renal tubular proximal cells with sodium diatrizoate, iopromide and iomeprol caused a marked dephosphorylation of the kinase Akt on Ser473 within 5min of incubation. RCM also caused a decrease in cell viability, which was substantially alleviated by transfecting the cells with a constitutively active form of Akt. Further downstream targets of Akt, including the Forkhead family of transcription factors FKHR and FKHRL1, were also dephosphorylated by RCM at Thr24 and Thr32, respectively. The P70S6 kinase was also dephosphorylated at Thr389 and Ser371 by RCM. However there was a more dramatic decrease in phosphorylation of the phosphorylated form of mammalian target of rapamycin (mTOR) and of the extracellular-signal regulated kinases (ERK) 1/2 caused by sodium diatrizoate than by iopromide. These results demonstrate the effect of RCM on some intracellular signaling pathways that may allow understanding of the mechanism of their toxicity and may allow the development of strategies to overcome their adverse effects.

Pharmacodynamics

Diatrizoate is the most commonly used water-soluble, iodinated, radiopaque x-ray contrast medium. Radiopaque agents are drugs used to help diagnose certain medical problems. They contain iodine, which blocks x-rays. Depending on how the radiopaque agent is given, it localizes or builds up in certain areas of the body. The resulting high level of iodine allows the x-rays to make a "picture" of the area. The areas of the body in which the radiopaque agent localizes will appear white on the x-ray film. This creates the needed distinction, or contrast, between one organ and other tissues. The contrast will help the doctor see any special conditions that may exist in that organ or part of the body.