Imiro350 mg/ml

Imiro is a non-ionic, low-osmolar iodinated contrast medium used to enhance visualization of internal structures during radiographic (X-ray/CT) imaging. It is an FDA-approved contrast agent with established uses across several imaging routes:

• Intrathecal use: myelography (lumbar, thoracic, cervical) and CT cisternography.
• Intravascular use: contrast-enhanced computed tomography (CT) of the head and body, excretory urography, cardiac ventriculography, coronary arteriography, and aortography/peripheral arteriography.
• Body cavity use: arthrography, endoscopic retrograde cholangiopancreatography (ERCP), and hysterosalpingography.
• Oral/gastrointestinal use: opacification of the GI tract when a water-soluble agent is preferred over barium.

Imiro is administered only by, or under the direct supervision of, a qualified physician or radiologist in a healthcare facility; it is not a self-administered outpatient medicine.

Each mL of Iohexol injection contains Iohexol (as the active pharmaceutical ingredient) in strengths typically expressed as mg iodine/mL (e.g., 140, 180, 210, 240, 300, or 350 mgI/mL), along with tromethamine buffer, edetate calcium disodium, and water for injection. Exact strength and pack size vary by manufacturer and locally registered product; refer to the specific product label for the strength dispensed.

Imiro is a triiodinated, non-ionic, water-soluble radiographic contrast agent belonging to the class of low-osmolar contrast media (LOCM). Because it is non-ionic, Imiro has lower osmolality and chemotoxicity compared with older ionic contrast agents, which translates into a generally better tolerability profile.

Imiro is supplied as a sterile, clear, colorless to pale yellow aqueous solution for injection or instillation, in single-dose vials or bottles, and is used exclusively in diagnostic imaging settings under professional supervision.

Mechanism: Iohexol contains covalently bound iodine atoms that attenuate (absorb) X-rays passing through the body. This creates radiographic contrast/density differences between the fluid or tissue containing Iohexol and surrounding structures, allowing better visualization of blood vessels, organs, the subarachnoid space, joints, or the GI tract, depending on the route of administration.

Pharmacokinetics: After intravascular administration, Iohexol distributes rapidly into the extracellular fluid space and does not appreciably bind to plasma proteins. It is not metabolized and is eliminated almost entirely unchanged by glomerular filtration, with a plasma elimination half-life of approximately 2 hours in patients with normal renal function. Elimination is prolonged in renal impairment. After intrathecal administration, Iohexol is absorbed from the cerebrospinal fluid into the blood and subsequently excreted renally in a similar manner.

Imiro is administered only by, or under direct supervision of, qualified medical personnel, via the route appropriate to the procedure:

• Intrathecal injection (myelography/cisternography)
• Intravenous or intra-arterial injection (CT, urography, angiography)
• Intra-articular instillation (arthrography)
• Instillation into a body cavity or duct (ERCP, hysterosalpingography)
• Oral or rectal administration (GI studies)

Patients should be adequately hydrated before and after intravascular administration, and should remain under observation for at least 30-60 minutes after injection to monitor for delayed hypersensitivity reactions.

Clinically significant interactions with Imiro:

• Metformin: In patients with renal impairment (eGFR 30-60 mL/min/1.73m²) or other risk factors, Imiro can precipitate acute kidney injury, increasing the risk of metformin-associated lactic acidosis. Metformin should be discontinued at or before the time of Imiro administration in at-risk patients and withheld for 48 hours after, restarting only after renal function is confirmed stable.
• Radioactive iodine (I-131/I-123) thyroid studies or therapy: Imiro saturates thyroidal iodine uptake mechanisms and can impair the accuracy of radioiodine thyroid uptake tests or the efficacy of radioiodine therapy for several weeks; such thyroid procedures should be deferred (commonly around 6 weeks) after Imiro administration.
• Neuroleptics/antipsychotics, tricyclic antidepressants, CNS stimulants, and other drugs that lower seizure threshold: these should be discontinued at least 48 hours before, and not resumed until 24 hours after, intrathecal (myelographic) use of Imiro, because of an increased risk of seizures.
• Interleukin-2 (IL-2) therapy: patients who have recently received IL-2 immunotherapy have an increased risk of delayed adverse reactions to Imiro.

Adverse effects of Imiro vary by route of administration.

• Intravascular (IV/intra-arterial) use: injection site pain or warmth, nausea, vomiting, flushing, headache, altered taste, and less commonly arrhythmias or transient visual disturbances.
• Intrathecal use (myelography): headache (common, up to ~18%), back or neck pain, nausea, and rarely seizures or aseptic meningitis.
• Oral/rectal use: diarrhea, nausea, vomiting, and abdominal discomfort.
• Intra-articular use: injection site pain and joint swelling.
• Serious but less common reactions: anaphylactoid/hypersensitivity reactions (ranging from mild urticaria to life-threatening bronchospasm, laryngeal edema, or anaphylactic shock), contrast-induced acute kidney injury, and cardiovascular events (arrhythmia, hypotension, rarely cardiac arrest).

Patients should seek immediate medical attention for difficulty breathing, swelling of the face/throat, severe rash, or chest pain after Imiro administration.

Pregnancy: Imiro should be used during pregnancy only if clearly needed and if the potential diagnostic benefit justifies the potential risk to the fetus; a physician should be consulted before use. Imiro is specifically contraindicated for hysterosalpingography during pregnancy or suspected pregnancy (see Contraindications).

Lactation: Imiro passes into breast milk in small amounts. As a precaution, a lactating mother may choose to pump and discard breast milk for approximately 10 hours after Imiro administration before resuming breastfeeding; this decision should be individualized with the treating physician, weighing the benefits of breastfeeding against the low potential for infant exposure.

Hypersensitivity reactions: Imiro can cause severe, potentially fatal anaphylactoid reactions. Resuscitation equipment, appropriate medications, and trained personnel must be immediately available whenever Imiro is administered. Patients with a history of asthma, allergy, or prior contrast reactions are at higher risk and may require premedication.

Renal considerations: Imiro can cause contrast-induced acute kidney injury, particularly in patients with pre-existing renal impairment, diabetes mellitus, dehydration, advanced age, or concurrent use of nephrotoxic drugs. Adequate hydration before and after administration is recommended, and renal function should be assessed beforehand in at-risk patients.

Intrathecal use: Only the concentration and dose recommended for intrathecal use should be used for myelography; inadvertent use of an incorrect formulation or excessive dose can cause severe neurotoxicity, seizures, or death. Patients should remain supine with head elevated after lumbar myelography and be monitored for several hours.

Thyroid function: Imiro contains iodine and can precipitate thyroid storm in patients with untreated hyperthyroidism/thyrotoxicosis, and can cause transient hypothyroidism, particularly in neonates and young infants (especially premature infants); thyroid function monitoring is recommended in at-risk pediatric patients.

Cardiovascular disease: Use with caution in patients with severe cardiac disease or pulmonary hypertension, as contrast administration can transiently affect hemodynamics.

Overdose of Imiro may occur with excessive dose or concentration, particularly via the intrathecal route, and can cause severe adverse effects including seizures, cardiovascular collapse, or acute kidney injury. There is no specific antidote for Imiro overdose. Any suspected overdose requires immediate medical attention; management is supportive and may include hemodynamic monitoring, seizure management, and hemodialysis to enhance elimination in patients with renal impairment. Contact emergency services or a poison control center immediately if overdose is suspected.

Store at room temperature (20-25°C/68-77°F); protect from light. Do not freeze. Use single-dose containers for one patient/procedure only and discard any unused portion. Keep out of reach of children.

Renal impairment: Use with caution; ensure adequate hydration and consider lower/adjusted doses; monitor renal function, especially in patients also taking metformin (see Interactions).

Hepatic impairment: No specific dose adjustment is established; Imiro is not hepatically metabolized, so hepatic impairment alone is not expected to significantly affect its handling, but caution is advised in patients with combined hepatorenal dysfunction.

Elderly: Use with caution due to higher likelihood of reduced renal function and cardiovascular comorbidity; dose based on body weight and renal function.

Pediatric patients: Imiro is approved for use in pediatric patients including neonates for certain indications, with weight-based dosing; monitor thyroid function in infants under 3 years of age, particularly premature infants, due to the risk of transient hypothyroidism.

Imiro is administered as a single dose for a single imaging procedure; it is not intended for repeated or continuous use. Repeat administration may be considered only if clinically necessary and only after adequate time has elapsed to reassess renal function and allow prior contrast to clear.

Radiographic contrast media; non-ionic, low-osmolar iodinated contrast agent.

Iohexol contains organically bound iodine, which attenuates X-rays as they pass through tissue or body fluid containing the agent, producing increased radiographic density/contrast that allows structures such as blood vessels, the urinary tract, the subarachnoid space, joints, or the GI tract to be visualized on imaging.

B

Imiro is approved for use in pediatric patients, including neonates, for specific imaging indications (e.g., IV urography, CT, cardiac angiography) with age- and weight-based dosing as specified in the product labeling. Because iodine-containing contrast agents can transiently suppress thyroid function, thyroid function should be monitored in infants under 3 years of age, especially those born prematurely, after Imiro exposure. Use in pediatric myelography and other specialized procedures should follow specialist protocols only, as safety and efficacy have not been established for all pediatric age groups and indications.