| Indication |
Metrizamide is used for lumbar, thoracic, cervical, and total columnar myelography to determine the presence of abnormalities in the spinal column, spinal canal, and central nervous system (CNS) as well as for cisternography by direct injection using standard radiologic techniques to visualize the basal cistern of the brain. For computerized tomography (CT) of the intracranial subarachnoid spaces and for ventriculography by direct injection using standard radiologic techniques to visualize the cerebral ventricles. Also used in pediatric angiocardiography to visualize lesions or malformations of the heart and obstructions or anomalies of the major thoracic vessels. Also used in adult peripheral arteriography to visualize specific regions of the vascular system and blood flow in such areas to help in the diagnosis and evaluation of neoplasms (known or suspected) or vascular diseases (congenital or acquired) that may cause changes in normal vascular anatomy or physiology. Metrizamide is also indicated in adults for intravenous digital arteriography of head and neck. |
| Mechanism of action |
Organic iodine compounds such as metrizamide block x-rays as they pass through the body, thereby allowing body structures containing iodine to be delineated in contrast to those structures that do not contain iodine. The degree of opacity produced by these compounds is directly proportional to the total amount (concentration and volume) of the iodinated contrast agent in the path of the x-rays. After intrathecal administration into the subarachnoid space, diffusion of metrizamide in the CSF allows the visualization of the subarachnoid spaces of the head and spinal canal. After intravascular administration, metrizamide makes opaque those vessels in its path of flow, allowing visualization of the internal structures until significant hemodilution occurs. Metrazamide also has some toxic effects which are thought to be due to its ability to inhibit glucose metabolism. |
| Absorption |
Absorption from gastrointestinal tract is negligible following oral or rectal administration. |
| Protein binding |
Not Available |
| Biotransformation |
Not Available |
| Route of elimination |
Not Available |
| Toxicity |
Non-ionic radiocontrast agents like metrizamide are cytotoxic to renal cells. The toxic effects include apoptosis, cellular energy failure, disruption of calcium homeostasis, and disturbance of tubular cell polarity, and are thought to be linked to oxidative stress. |
| Affected organisms |
|