Iohexol ICG farma: Uses, Dosage & Side Effects

What Is Iohexol ICG farma and What Is It Used For?

Iohexol ICG farma contains the active substance iohexol, a non-ionic, monomeric, tri-iodinated benzoic acid derivative. Each milliliter of the solution contains iohexol equivalent to 300 mg of iodine (commonly expressed as 300 mg I/mL). Iohexol was developed in the late 1970s and early 1980s as part of a new generation of contrast agents designed to address the significant adverse reaction rates associated with older, ionic (high-osmolar) contrast media. It was first approved for clinical use in 1985 and has since become one of the most widely used contrast agents in the world, administered in hundreds of millions of diagnostic procedures globally.

The fundamental principle behind iodinated contrast media is the ability of iodine atoms to absorb X-rays. When iohexol is injected into the bloodstream or into a body cavity, the iodine-containing molecules distribute through the target tissues and absorb a significantly greater proportion of X-rays than the surrounding soft tissues or blood. This differential absorption creates contrast on radiographic images, allowing radiologists and other clinicians to visualize structures that would otherwise be difficult or impossible to distinguish. The three iodine atoms per molecule of iohexol provide excellent radiopacity, while the non-ionic chemical structure minimizes osmotoxicity and chemotoxicity.

The key innovation of iohexol compared to earlier ionic contrast agents lies in its molecular design. Ionic contrast media dissociate into charged particles (ions) in solution, resulting in solutions with very high osmolality (often five to eight times that of plasma). This high osmolality is a major cause of adverse effects, including pain during injection, vasodilation, cardiac effects, and a higher incidence of allergic-like reactions. Iohexol, being non-ionic, does not dissociate in solution. Its osmolality (approximately 640 mOsm/kg at 300 mg I/mL) is substantially lower than ionic agents, though still about twice that of plasma. This low-osmolar profile translates directly into improved patient comfort, fewer hemodynamic effects, and a lower overall incidence of adverse reactions.

Iohexol ICG farma at 300 mg I/mL concentration is used across a wide range of diagnostic imaging procedures. The most common clinical applications include:

• Computed Tomography (CT) with contrast enhancement: Iohexol is injected intravenously to enhance the visibility of blood vessels, tumors, areas of inflammation, and organ parenchyma during CT scans of the brain, chest, abdomen, pelvis, and extremities. Contrast-enhanced CT is one of the most frequently performed diagnostic imaging procedures worldwide.
• Angiography and vascular imaging: Intra-arterial injection of iohexol allows detailed visualization of arteries and veins, essential for diagnosing stenosis, aneurysms, vascular malformations, and peripheral vascular disease. This includes coronary angiography, cerebral angiography, and peripheral arteriography.
• Urography (intravenous pyelography): After intravenous injection, iohexol is filtered by the kidneys and concentrated in the urinary tract, allowing visualization of the kidneys, ureters, and bladder. This is used to diagnose kidney stones, urinary tract obstruction, congenital abnormalities, and tumors of the urinary system.
• Myelography: Iohexol can be injected into the subarachnoid space (intrathecally) to outline the spinal cord, nerve roots, and surrounding cerebrospinal fluid. Myelography is used to evaluate spinal stenosis, herniated discs, tumors, and other causes of spinal cord or nerve root compression, although MRI has largely replaced this indication in many settings.
• Arthrography: Injection into joints allows visualization of joint structures, cartilage, ligaments, and the joint capsule, useful for diagnosing tears, loose bodies, and other intra-articular pathology.
• Gastrointestinal studies: Oral administration of iohexol can be used as an alternative to barium for gastrointestinal tract imaging, particularly when there is a risk of bowel perforation or when a water-soluble contrast agent is preferred.

Iohexol is recognized by the World Health Organization (WHO) as an essential medicine. It appears on the WHO Model List of Essential Medicines, reflecting its critical importance in diagnostic imaging worldwide. The European Medicines Agency (EMA), the U.S. Food and Drug Administration (FDA), and regulatory agencies globally have approved iohexol-based contrast media for clinical use. The American College of Radiology (ACR) and the European Society of Urogenital Radiology (ESUR) both include iohexol in their guidelines and manuals on contrast media safety and utilization.

What Should You Know Before Receiving Iohexol ICG farma?

Contraindications

The primary contraindication to iohexol is known hypersensitivity to iohexol or to any other iodinated contrast media. Patients who have experienced a previous severe or anaphylactic reaction to an iodinated contrast agent should generally not receive iohexol unless the clinical benefit clearly outweighs the risk and appropriate premedication and emergency preparedness measures are in place. It is important to note that a previous reaction to one iodinated contrast medium increases the risk of reacting to another, although cross-reactivity is not universal.

Intrathecal administration (myelography) has additional contraindications, including known active infection at the injection site, uncontrolled seizure disorders, and conditions that significantly increase intracranial pressure. Iohexol should not be administered intrathecally to patients with a history of epilepsy unless the potential diagnostic benefit outweighs the seizure risk, and prophylactic anticonvulsant therapy should be considered.

Manifest thyrotoxicosis (overactive thyroid) is a contraindication for intravascular iodinated contrast media, as the iodine load can exacerbate hyperthyroidism. Patients with latent hyperthyroidism or thyroid autonomy (such as multinodular goiter) are also at risk for iodine-induced thyrotoxicosis and require careful evaluation before contrast administration.

Warnings and Precautions

Before administering iohexol, healthcare professionals must consider several important patient-specific factors:

• Renal impairment: Iohexol is eliminated almost entirely by glomerular filtration. In patients with impaired kidney function (eGFR < 30 mL/min/1.73 m² for intra-arterial administration, or eGFR < 30 mL/min for intravenous administration with specific risk factors), the risk of contrast-induced nephropathy (CIN) or post-contrast acute kidney injury (PC-AKI) is significantly increased. Risk factors include pre-existing chronic kidney disease, diabetes mellitus (particularly with nephropathy), dehydration, heart failure, advanced age, concurrent use of nephrotoxic medications, and use of large volumes of contrast. Prophylactic intravenous hydration with isotonic saline before and after the procedure is the most effective preventive strategy.
• Allergic-like reactions: Anaphylactoid reactions to non-ionic contrast media occur in approximately 0.2–0.7% of patients. Risk factors include a previous reaction to iodinated contrast media (which increases the risk 5–6 fold), a history of asthma (particularly uncontrolled asthma), and a history of significant allergies. High-risk patients may benefit from premedication with corticosteroids and antihistamines. Emergency resuscitation equipment and trained personnel must be immediately available whenever iodinated contrast is administered.
• Thyroid disorders: Iodinated contrast media deliver a large iodine load (a single injection can provide thousands of times the daily recommended iodine intake). This can precipitate thyrotoxicosis in patients with latent hyperthyroidism, particularly those with multinodular goiter or Graves' disease. Conversely, the iodine load can transiently suppress thyroid function in euthyroid patients (Wolff-Chaikoff effect). Thyroid function should be assessed in patients with known or suspected thyroid disease before contrast administration.
• Pheochromocytoma: Patients with known or suspected pheochromocytoma are at risk of hypertensive crisis following intravascular contrast injection. Alpha-adrenergic blockade should be established before the procedure.
• Myasthenia gravis: Iodinated contrast media may exacerbate symptoms of myasthenia gravis. Careful clinical monitoring is required.
• Sickle cell disease: Iodinated contrast media can promote sickling of red blood cells in patients with homozygous sickle cell disease. The contrast agent should be used with caution, adequate hydration should be ensured, and the lowest effective dose should be used.

Pregnancy and Breastfeeding

The safety of iohexol during pregnancy has not been established in adequate controlled studies. Iodinated contrast media cross the placenta and can enter the fetal circulation. The primary concern is the potential effect of free iodide on the fetal thyroid gland, particularly during the second and third trimesters when the fetal thyroid is actively concentrating iodine. Animal reproductive studies have not demonstrated teratogenic effects. However, as a precaution, iohexol should only be used during pregnancy when the diagnostic benefit clearly outweighs the potential risk to the fetus. If contrast-enhanced imaging is essential during pregnancy, MRI without gadolinium or ultrasound should be considered as alternatives where diagnostically appropriate.

Iohexol is excreted in breast milk in very small quantities (less than 1% of the administered dose). Given the extremely low concentration in breast milk and the poor oral bioavailability of iohexol from the gastrointestinal tract, the amount absorbed by a breastfeeding infant is negligible. Both the American College of Radiology (ACR) and the European Society of Urogenital Radiology (ESUR) state that mothers may continue breastfeeding without interruption after receiving iodinated contrast media. However, mothers who remain concerned may choose to express and discard breast milk for 12–24 hours after the procedure.

Children

Iohexol can be used in pediatric patients, including neonates, for appropriate diagnostic indications. Pediatric dosing is calculated based on body weight and the specific imaging procedure. Neonates and infants are more vulnerable to contrast-induced renal effects and thyroid disturbance due to their immature renal function and sensitivity to iodine. Thyroid function should be monitored in neonates who receive iodinated contrast media, particularly premature infants, as transient hypothyroidism has been reported. Adequate hydration is essential in all pediatric patients receiving iohexol.

Importance of Hydration

Adequate hydration is one of the most important factors in preventing adverse renal effects from iohexol and other iodinated contrast media. Dehydration concentrates the contrast agent in the kidneys, increasing the risk of tubular damage and contrast-induced nephropathy. Patients should be well hydrated before the procedure, and intravenous hydration with isotonic saline (typically 1 mL/kg/hour for 6–12 hours before and 4–12 hours after the procedure) is recommended for patients at increased risk of renal complications. Patients should also be encouraged to drink plenty of fluids after the procedure to help eliminate the contrast agent from the body.

How Does Iohexol ICG farma Interact with Other Drugs?

While iohexol itself is pharmacologically inert (it is not metabolized and does not bind to plasma proteins), several clinically significant drug interactions must be considered when administering iodinated contrast media. These interactions relate primarily to the effects of iohexol on renal function, thyroid physiology, and the potential for allergic-like reactions, rather than direct pharmacokinetic drug-drug interactions.

Metformin and Iodinated Contrast: Detailed Guidance

The interaction between metformin and iodinated contrast media is one of the most clinically important considerations in radiology practice. Metformin itself is not nephrotoxic, but it is eliminated exclusively by the kidneys. If iohexol causes even a transient decline in renal function (contrast-induced nephropathy), metformin can accumulate in the body to toxic levels, potentially leading to metformin-associated lactic acidosis (MALA), a rare but life-threatening condition with a mortality rate of approximately 50%.

Current guidelines from the ACR and ESUR stratify management based on renal function. For patients with normal kidney function (eGFR ≥ 30 mL/min/1.73 m²) undergoing intravenous contrast administration, metformin can be continued without interruption. For patients with significantly impaired renal function (eGFR < 30), or those undergoing intra-arterial catheter studies with the possibility of renal artery contrast exposure, metformin should be temporarily discontinued at the time of the procedure and not restarted until renal function has been reassessed at 48 hours and found to be stable.

Nephrotoxic Medications

Concurrent use of other nephrotoxic drugs increases the risk of contrast-induced acute kidney injury. Non-steroidal anti-inflammatory drugs (NSAIDs), aminoglycoside antibiotics, vancomycin, amphotericin B, cisplatin, and ciclosporin are among the agents that should ideally be withheld for 24–48 hours before and after iohexol administration in patients with impaired renal function. This is not always clinically feasible, and the decision to continue or withhold these medications must be made on an individual basis, weighing the diagnostic need against the renal risk.

What Is the Correct Dosage of Iohexol ICG farma?

Unlike therapeutic medications taken at home, iohexol is a diagnostic agent administered exclusively by healthcare professionals in controlled clinical settings. The dosage is individualized for each patient and each procedure, based on factors including the type of examination, the route of administration, the patient's body weight, age, cardiac output, and renal function. The overarching principle is to use the lowest dose that provides adequate diagnostic opacification, particularly in patients at increased risk of adverse effects.

Adults

Children

Pediatric dosing of iohexol is based on body weight. For intravenous contrast-enhanced CT, the typical dose is 1–2 mL/kg of body weight, with a maximum not exceeding the adult dose. Neonates and infants require special attention to fluid balance, renal function, and thyroid monitoring. The European Society of Paediatric Radiology (ESPR) and the Image Gently Alliance provide specific guidelines for contrast use in children, emphasizing the importance of using the lowest effective dose and ensuring adequate hydration.

Elderly

Elderly patients are at increased risk of contrast-induced nephropathy due to age-related decline in renal function, which may not be fully reflected by serum creatinine levels alone (eGFR should be calculated). Lower injection rates may be appropriate due to reduced cardiac output. Adequate hydration before and after the procedure is particularly important in this population. The dose should be kept to the minimum effective amount.

Patients with Renal Impairment

In patients with reduced kidney function, the lowest possible dose of iohexol should be used. The European Society of Urogenital Radiology (ESUR) recommends that, where clinically appropriate, alternative imaging modalities that do not require iodinated contrast (such as ultrasound, MRI, or non-contrast CT) should be considered. When iodinated contrast is essential, prophylactic intravenous hydration with normal saline is the most evidence-based approach to preventing contrast-induced acute kidney injury. The minimum waiting period between repeated contrast-enhanced procedures should be at least 48 hours to allow renal recovery.

Overdose

Overdose with iohexol is unlikely in routine clinical practice because it is administered by trained healthcare professionals using standardized protocols. However, in the event of accidental overdose, symptoms may include fluid overload, electrolyte disturbances, and acute kidney injury. Treatment is supportive: ensure adequate hydration, monitor renal function, electrolytes, and fluid balance carefully. Iohexol can be removed from the body by hemodialysis, which may be considered in cases of severe overdose, particularly in patients with pre-existing renal impairment. There is no specific antidote.

What Are the Side Effects of Iohexol ICG farma?

Like all iodinated contrast media, iohexol can cause adverse reactions, although the overall safety profile of non-ionic, low-osmolar agents is considerably better than that of older ionic contrast media. The majority of adverse reactions are mild, self-limiting, and require no treatment. However, rare but serious and potentially life-threatening reactions can occur, and all facilities administering iodinated contrast media must be equipped and staffed to manage acute allergic-like reactions, including anaphylaxis.

Adverse reactions to iohexol can be broadly categorized as either physiological (related to the osmolality, chemotoxicity, and volume of the contrast agent) or allergic-like (idiosyncratic reactions that resemble allergic reactions but are not mediated by traditional IgE antibody mechanisms in most cases). The following frequency classification is based on the European Union frequency convention:

Delayed Adverse Reactions

While most adverse reactions to iohexol occur within 30–60 minutes of administration, delayed reactions can develop hours to days after the procedure. Delayed reactions are typically skin-related, including rash, urticaria, pruritus, and, very rarely, more serious skin reactions. Delayed reactions are more common in patients who have received interleukin-2 therapy, those with a history of previous delayed contrast reactions, and patients with autoimmune conditions. Most delayed reactions are self-limiting and resolve within 3–7 days, but patients should be advised to seek medical attention if they develop significant skin reactions or other symptoms after discharge.

Contrast-Induced Nephropathy (CIN)

Contrast-induced nephropathy, now more commonly referred to as post-contrast acute kidney injury (PC-AKI), is defined as a rise in serum creatinine of ≥ 0.3 mg/dL (26.5 μmol/L) or a ≥ 50% increase from baseline within 48–72 hours of contrast administration, in the absence of another clear cause. The incidence in the general population with normal renal function is very low (less than 1–2%), but it increases significantly in patients with pre-existing chronic kidney disease, diabetes, heart failure, and those who are dehydrated. In most cases, PC-AKI is self-limiting, with creatinine returning to baseline within 7–14 days. However, in a small proportion of patients, particularly those with severely impaired renal function, it can progress to persistent renal failure requiring dialysis.

How Should You Store Iohexol ICG farma?

Iohexol ICG farma is a hospital-grade pharmaceutical product that is stored and handled by healthcare professionals in clinical settings. Patients do not typically need to store this medication at home, as it is administered in hospitals, radiology departments, and specialized imaging centers. However, understanding proper storage conditions is important for ensuring the safety and efficacy of the product.

The recommended storage conditions for Iohexol ICG farma are as follows:

• Temperature: Store below 30°C (86°F). Do not freeze. Freezing can alter the physicochemical properties of the solution and potentially create particulate matter. If the product has been accidentally frozen, it must not be used.
• Light protection: Store in the original packaging to protect from light. Prolonged exposure to light and X-rays can cause degradation of the iohexol molecule, potentially leading to the formation of free iodide and other breakdown products that increase the risk of adverse reactions.
• Visual inspection: Before use, the solution must be visually inspected. It should be clear and colorless to pale yellow. Do not use if the solution is discolored, cloudy, or contains visible particulate matter.
• Single use: Iohexol ICG farma vials are intended for single use. Any unused solution remaining after the procedure must be discarded. Multi-dose vials, if available, must be used in accordance with local guidelines for multi-dose container management, and unused portions should be discarded within the specified timeframe (typically within 24 hours of first use).
• Shelf life: The shelf life is indicated on the product packaging and must not be exceeded. Do not use after the expiration date printed on the vial and carton.

Contrast media warming devices are commonly used in radiology departments to bring iohexol to body temperature (37°C) before injection. Warming the contrast medium reduces its viscosity, making it easier to inject (particularly through small-gauge catheters at high flow rates), and improves patient comfort by reducing the sensation of coldness during injection. Contrast warming should be performed using approved warming devices and should not exceed the manufacturer's recommended maximum temperature and warming duration.

What Does Iohexol ICG farma Contain?

Understanding the composition of Iohexol ICG farma is important for identifying potential sensitivities to its components and for understanding its physicochemical properties.

Active Ingredient

The active substance is iohexol, a non-ionic, monomeric, water-soluble iodinated contrast medium. Its chemical name is 5-[acetyl(2,3-dihydroxypropyl)amino]-N,N'-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophthalamide. The molecular formula is C₁₉H₂₆I₃N₃O₉, and its molecular weight is 821.14 g/mol. Each molecule contains three iodine atoms, which are responsible for the X-ray attenuation properties that make it useful as a contrast agent.

At a concentration of 300 mg I/mL, the solution has the following physicochemical properties:

• Osmolality: Approximately 640 mOsm/kg water (low-osmolar, approximately twice that of plasma)
• Viscosity: Approximately 6.3 mPa·s at 37°C
• Density: Approximately 1.349 g/mL at 37°C
• pH: 6.8–7.7

Excipients (Inactive Ingredients)

• Trometamol (tromethamine): Used as a buffering agent to maintain the pH of the solution within the optimal range (6.8–7.7), which is close to physiological pH and helps minimize tissue irritation.
• Hydrochloric acid: Used for pH adjustment during manufacturing to achieve the target pH range.
• Edetate calcium disodium (calcium EDTA): Acts as a stabilizing agent (chelating agent) that binds trace metal ions that could otherwise catalyze degradation of the iohexol molecule. This helps maintain the stability and purity of the solution throughout its shelf life.
• Water for injections: The solvent, prepared to pharmacopeial standards to ensure sterility and freedom from pyrogens (fever-causing substances).

The formulation does not contain preservatives, antimicrobial agents, or latex components. It is essentially sodium-free, which is relevant for patients on sodium-restricted diets. The solution contains no particles of natural rubber or latex. Patients with known allergies to any of the listed excipients should inform their healthcare provider before the procedure.