Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ISOVUE-M 200 vs ISOVUE-250
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Iodinated radiocontrast agent that attenuates X-rays, allowing visualization of vascular structures and organs during imaging procedures.
Iopamidol is a nonionic, water-soluble iodinated radiographic contrast agent that attenuates X-rays, thereby providing contrast enhancement in imaging studies. Its mechanism of action is physical rather than pharmacological, as it does not have inherent biological activity.
Intrathecal administration for myelography (lumbar, thoracic, cervical, and total columnar),CT cisternography,Ventriculography
Intravascular use for computed tomography (CT) of the head and body,Intrathecal use for lumbar, thoracic, and cervical myelography,Coronary arteriography and ventriculography,Peripheral arteriography,Excretory urography,Visceral angiography
Intrathecal: 8-12 m L (200 mg Iodine/m L) for lumbar myelography. Intravenous: 50-200 m L for contrast enhancement, administered as a bolus or infusion per procedure.
Intravenous administration of 50-150 m L (12-37 g iodine) for CT imaging; intra-arterial administration of 10-80 m L (2.5-20 g iodine) for angiography; dose depends on procedure and patient weight.
Terminal elimination half-life is approximately 1.5–2 hours in patients with normal renal function. Prolonged in renal impairment, which may necessitate dose adjustment.
Terminal elimination half-life: 1.5-2 hours (normal renal function); clinically, half-life prolonged in renal impairment
Not metabolized; excreted unchanged by the kidneys. Undergoes passive resorption from cerebrospinal fluid into plasma.
Iopamidol is not metabolized. It is excreted unchanged by glomerular filtration, primarily via the kidneys. In patients with normal renal function, 90% or more of the administered dose is eliminated in the urine within 24 hours.
Primarily renal: >90% of the administered dose is excreted unchanged in urine within 24 hours. Less than 1% is excreted via biliary/fecal routes.
Primarily renal: 90-95% unchanged in urine within 24 hours; biliary/fecal: <5%
Negligible, <2% bound to plasma proteins.
<5% bound; primarily to albumin
Approximately 0.3–0.4 L/kg, consistent with distribution into extracellular fluid space.
0.2-0.3 L/kg; reflects distribution in extracellular fluid (does not cross intact blood-brain barrier)
Not applicable; administered intravenously or intra-arterially, with 100% bioavailability by these routes.
Intravascular: 100%; oral: negligible (<1%)
e GFR ≥30 m L/min: No adjustment. e GFR <30 m L/min: Contraindicated due to risk of nephrogenic systemic fibrosis (NSF) with gadolinium-based agents; however, for iopamidol-based Isovue-M 200, renal impairment requires dose reduction and careful monitoring. In severe renal impairment (e GFR <30 m L/min), use lowest effective dose and ensure adequate hydration; consider alternative imaging.
e GFR <30 m L/min/1.73m²: avoid use or use minimal dose with adequate hydration; e GFR 30-59: consider lowest effective dose and ensure hydration; no specific dose reduction for e GFR ≥60.
No specific Child-Pugh based adjustments recommended; use with caution in severe hepatic impairment due to potential for contrast-induced nephropathy and systemic effects.
No specific Child-Pugh based dose modifications; use with caution in severe hepatic impairment due to potential contrast-induced nephropathy risk.
Intrathecal: 0.2-0.4 m L/kg (up to 12 m L total) for myelography. Intravenous: 1.5-2.5 m L/kg (max 200 m L) for CT or angiography, adjusted per procedure.
Children: 1-2 m L/kg (250-500 mg iodine/kg) intravenously for CT, not to exceed adult dose; adjust for body weight and procedure.
Use with caution due to increased prevalence of renal impairment, cardiovascular disease, and dehydration. Assess renal function before use; ensure adequate hydration; consider lower doses and longer intervals between procedures.
Elderly patients: use lowest effective dose; ensure adequate hydration; monitor renal function closely due to age-related decline and increased risk of nephropathy.
Risk of serious adverse reactions including anaphylaxis, seizures, and neurological complications when administered intrathecally. Use only by physicians trained in myelography and familiar with the procedure. Resuscitative equipment and trained personnel must be immediately available.
Intrathecal administration may result in neurotoxicity including seizures, meningitis, and arachnoiditis. Inadvertent intravascular injection during intrathecal administration may cause serious adverse reactions.
Risk of anaphylactoid reactions, especially in patients with history of allergy or bronchial asthma,Seizures may occur, particularly in patients with epilepsy or when concurrent medications lower seizure threshold,Renal impairment delays elimination and increases risk of adverse effects,Adequate hydration before and after procedure is essential,Neurotoxicity: avoid hemorrhage or infection at puncture site, do not use in patients with increased intracranial pressure
Do not use for myelography if procedures are contraindicated,Risk of serious adverse reactions in patients with impaired renal function, including acute renal failure,Risk of cardiorespiratory arrest, anaphylactic shock, and other severe allergic reactions,Potential for thyroid storm in patients with hyperthyroidism,Caution in patients with pheochromocytoma, sickle cell disease, and multiple myeloma
Known hypersensitivity to iopamidol or any component of the formulation,Concurrent intrathecal administration of corticosteroids or other contrast agents,Blood in CSF (hemorrhagic puncture) due to increased risk of neurotoxicity,History of seizures or epilepsy (relative contraindication depending on benefit-risk),Severe renal impairment (relative, may be used after dialysis if necessary)
History of severe allergic reaction to iopamidol or any component of the formulation,Intrathecal administration in patients with thrombophlebitis, infection, or malignancy at the injection site,Severe renal impairment (anuria, oliguria) unless the benefits outweigh the risks,Patients with a history of grand mal seizures, or those on drugs that lower seizure threshold, for intrathecal use
No specific food interactions. Maintain adequate hydration before and after contrast administration. Avoid alcohol consumption for 24 hours post-procedure as it may exacerbate CNS side effects.
No known food interactions. However, ensure adequate hydration before and after the procedure. Avoid alcohol 24 hours prior as it may increase risk of dehydration.
Iopamidol (ISOVUE-M 200) is a nonionic iodinated contrast agent. Animal reproduction studies have not been conducted. It is not known whether iopamidol can cause fetal harm when administered to a pregnant woman. However, iodinated contrast agents cross the placenta and accumulate in the fetal thyroid, potentially causing hypothyroidism. Use during pregnancy should be limited to situations where the diagnostic benefit clearly outweighs the risk. First trimester exposure is not advised due to organogenesis. Second and third trimester use may be considered with caution, but neonatal thyroid function should be assessed after birth.
ISOVUE-250 (iopamidol) is an iodinated contrast agent. In pregnant women, exposure to ionizing radiation from procedures involving iodinated contrast should be minimized. Iodinated contrast agents cross the placenta and may produce transient neonatal hypothyroidism if used in the third trimester. However, data from clinical studies are insufficient to determine a definitive teratogenic risk. First trimester exposure has not been associated with major congenital malformations, but caution is warranted due to potential fetal hypothyroidism with prolonged use near term.
Iopamidol is excreted into human breast milk in very small amounts. The milk-to-plasma ratio (M/P) is approximately 0.01. After IV administration, the amount ingested by a nursing infant is minimal (<0.1% of the maternal dose). Because of the low bioavailability of oral iodinated contrast agents, adverse effects in the infant are unlikely. The American College of Radiology considers it safe to continue breastfeeding after use of iodinated contrast agents. However, some guidelines suggest discarding breast milk for 12-24 hours after administration if desired.
Limited data suggest that iopamidol is excreted into human breast milk in very small amounts. The milk-to-plasma (M/P) ratio is not specifically reported for iopamidol, but for similar iodinated contrast agents, the M/P ratio is low (<0.2). The amount of iodine transferred to the infant is negligible and unlikely to cause adverse effects. However, the American College of Radiology and other guidelines recommend that breastfeeding may be continued without interruption after receiving iodinated contrast, although some advise discarding milk for 12-24 hours if the mother is concerned.
No specific dose adjustment is required for iopamidol (ISOVUE-M 200) during pregnancy. However, the lowest effective dose necessary for diagnostic imaging should be used. The physiological changes of pregnancy (increased plasma volume, renal blood flow and GFR) may alter the pharmacokinetics of iopamidol, potentially leading to faster clearance. Nonetheless, no dose adjustment is recommended as contrast dosing is weight-based and the agent is used as a single dose for imaging.
Pregnancy does not require dose adjustments for ISOVUE-250. The dose should be based on the diagnostic procedure and patient weight. However, because of potential fetal hypothyroidism risk from free iodide, alternative imaging modalities without iodinated contrast should be considered if possible, especially in the third trimester.
ISOVUE-M 200 (iopamidol) is a nonionic, low-osmolar iodinated contrast medium used for intrathecal administration in myelography. Pre-hydrate patients to reduce risk of contrast-induced nephropathy. Have resuscitation equipment available due to risk of anaphylactoid reactions. Avoid in patients with known hypersensitivity to iodine-containing compounds. Monitor for delayed adverse effects such as headache, nausea, and meningeal irritation.
ISOVUE-250 (iopamidol 51%) is a nonionic, low-osmolality iodinated contrast medium used for angiography, urography, and CT enhancement. In patients with renal impairment (e GFR <30 m L/min), consider N-acetylcysteine prophylaxis and hydration to reduce risk of contrast-induced nephropathy. Monitor for delayed hypersensitivity reactions, which can occur up to 7 days post-administration. Use caution in patients with pheochromocytoma; pre-treat with alpha-blockers. Shellfish allergy is not a contraindication; true iodine allergy is rare. For intrathecal use, avoid concurrent neurotoxic drugs and ensure patient hydration.
Inform your healthcare provider if you have any allergies, especially to iodine or contrast agents.,Tell your doctor if you have kidney problems, diabetes, or are taking certain medications like metformin.,Drink plenty of fluids before and after the procedure to help flush the contrast from your body.,You may experience headache, nausea, or back pain after the injection; report severe or persistent symptoms.,Avoid driving or operating machinery for at least 24 hours after the procedure due to possible dizziness or drowsiness.,Inform your doctor if you are pregnant, breastfeeding, or suspect you may be pregnant.
Inform your doctor if you have kidney disease, diabetes, or are taking metformin; metformin may need to be stopped temporarily.,Tell your doctor about all allergies, especially to medications or iodine.,You may feel warmth, flushing, or a metallic taste when the contrast is injected; this is normal.,Drink plenty of water before and after the procedure to help flush the contrast from your body.,Report any symptoms like hives, itching, difficulty breathing, or swelling of the face/mouth immediately.,If you are pregnant or breastfeeding, discuss potential risks with your doctor.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ISOVUE-M 200 vs ISOVUE-250, answered by our medical review team.
ISOVUE-M 200 is a Contrast Media that works by Iodinated radiocontrast agent that attenuates X-rays, allowing visualization of vascular structures and organs during imaging procedures.. ISOVUE-250 is a Contrast Media that works by Iopamidol is a nonionic, water-soluble iodinated radiographic contrast agent that attenuates X-rays, thereby providing contrast enhancement in imaging studies. Its mechanism of action is physical rather than pharmacological, as it does not have inherent biological activity.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ISOVUE-M 200 and ISOVUE-250 depend on the specific clinical indication. These are both Contrast Media agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ISOVUE-M 200 is: Intrathecal: 8-12 m L (200 mg Iodine/m L) for lumbar myelography. Intravenous: 50-200 m L for contrast enhancement, administered as a bolus or infusion per procedure.. The standard adult dose of ISOVUE-250 is: Intravenous administration of 50-150 m L (12-37 g iodine) for CT imaging; intra-arterial administration of 10-80 m L (2.5-20 g iodine) for angiography; dose depends on procedure and patient weight.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ISOVUE-M 200 and ISOVUE-250 in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ISOVUE-M 200 is classified as Category C. Iopamidol (ISOVUE-M 200) is a nonionic iodinated contrast agent. Animal reproduction studies have not been conducted. It is not known whether iopamidol can cause fetal harm when ad. ISOVUE-250 is classified as Category C. ISOVUE-250 (iopamidol) is an iodinated contrast agent. In pregnant women, exposure to ionizing radiation from procedures involving iodinated contrast should be minimized. Iodinated. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.