Lipiodol (ethiodized oil) is a specialized contrast agent used in diagnostic radiology to support image visualization during specific medical procedures. Its role is to help outline certain internal structures, contributing to the visual information available to healthcare providers.

The medication is used across several therapeutic domains. In adults, Lipiodol is indicated for hysterosalpingography and selective hepatic intra-arterial use for imaging tumors in patients with known hepatocellular carcinoma (HCC). It is also approved for lymphography in both adult and pediatric patients. The primary benefit of the medication is to support procedures that rely on clear visualization of body structures for diagnostic purposes.

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Quick Fact: Relief for Diagnostic Uncertainty

Lipiodol may support the visualization of targeted body structures for diagnostic purposes.

Eligibility Scope

Populations for whom use is allowed: Adults are approved for all labeled uses, including Hysterosalpingography and Selective Hepatic Intra-arterial use. Pediatric patients are eligible for Lymphography.

Populations for whom use is contraindicated: Absolute contraindications include known hypersensitivity to the medicine or iodine, manifest hyperthyroidism, and conditions involving recent bleeding or traumatic injuries. Procedure-specific bans include intrauterine pregnancy for Hysterosalpingography and a right-to-left cardiac shunt or advanced pulmonary disease for Lymphography.

Age-related eligibility rules: While Lymphography is approved for children, use for HCC procedures is not established in the pediatric population. Older adults with underlying cardiovascular or respiratory diseases require special care.

Condition-specific eligibility rules: Use for hepatic procedures is not recommended in patients with decompensated liver cirrhosis (Child-Pugh ge 8). The medicine is contraindicated for Hysterosalpingography during pregnancy, and discontinuation of nursing is recommended during breastfeeding.

Eligibility Classifications (High-Level)

Eligibility severity classification (as defined in official documents): Contraindicated, Not Recommended, Special Care, and Use Not Established.

Regulatory basis: Official Prescribing Information from the FDA and the SmPC from the EMA and global authorities.

Resulting Eligibility Structure

Official eligibility statements: • Patients with known hypersensitivity to iodine or manifest hyperthyroidism must not use Lipiodol (absolute contraindications). • Use is not established in children for selective hepatic intra-arterial procedures. • The medicine is contraindicated for Hysterosalpingography if intrauterine pregnancy is present.

Connection to the overall eligibility profile (2–4 sentences): Regulatory documents define who can and cannot use the medicine by strictly listing absolute contraindications related to hypersensitivity and systemic disease, alongside procedure-specific exclusions. The profile further includes restrictions based on organ function, such as limiting use in patients with decompensated liver cirrhosis, all of which determines the permitted clinical population according to government labeling.

Interaction Map: Interactions with other medicines and products — official regulatory information for Lipiodol

Interaction Scope
Medicinal product categories with documented interactions: Radioactive agents, Antihypertensives (including ACE inhibitors, ARBs, Beta-blockers, Diuretics), Nephrotoxic agents, Immunomodulators.
Specific interacting medicines (if explicitly listed): Metformin, Sodium Iodide I-131, Methoxyflurane, Iobenguane I 123, Ioflupane I 123.
Mechanistic basis of interactions (only if stated in label): Pharmacodynamic effects (e.g., increased toxicity, adverse reaction risk), Clearance alteration (resulting in increased plasma levels), Interference with thyroid iodine uptake.
Timing-based interaction rules (if applicable): Mandatory discontinuation of Metformin 48 hours before and resumption no earlier than two days after intra-arterial use. Mandatory discontinuation of Lipiodol for up to 6 months prior to Sodium Iodide I-131 administration.
Population-specific interaction notes (if applicable): Pregnant women (potential for interference with fetal thyroid function). Elderly patients with pre-existing cardiovascular/respiratory disease (documented increased risk of serious adverse reactions).
Interaction-related restrictions: Formal regulatory avoidance of co-administration with Methoxyflurane and Sodium Iodide I-131.

Interaction Classifications (High-Level)
Interaction severity classification (as defined in official documents): Contraindicated combinations (Risk X), Use-with-caution combinations.
Regulatory basis (EMA / FDA / etc.): FDA Prescribing Information, European Summary of Product Characteristics (SmPC) equivalents.
Interaction-context constraints (as defined in official documents): Interactions are documented primarily in the context of diagnostic procedures and intra-arterial administration.

Official Interaction Statements:

• Co-administration with Methoxyflurane is officially prohibited due to the potential for increased nephrotoxic effects.
• Sodium Iodide I-131 requires mandatory discontinuation of Lipiodol for up to 6 months prior to administration to prevent interference with therapeutic efficacy.
• Metformin requires mandatory discontinuation 48 hours prior to intra-arterial use and resumption two days after to mitigate lactic acidosis risk.
• Ethiodized oil officially increases the plasma levels of agents like Iobenguane I 123 through documented alteration of renal clearance.
• Antihypertensive agents may officially reduce the effectiveness of cardiovascular compensatory mechanisms during the procedure.
• Interactions with food or alcohol are not officially documented in regulatory sources.

Connection to the overall interaction profile:

The regulatory documents define Lipiodol’s interaction structure primarily through its unique composition and prolonged systemic retention, establishing specific contraindications and mandatory timing rules. Official classification includes both pharmacodynamic reinforcement with vasoactive drugs and clearance alteration affecting radiopharmaceuticals, demanding heightened monitoring protocols. The interaction profile is dominated by procedural and clearance constraints rather than typical metabolic interactions.

Radiographic Contrast: The Iodine-Attenuation Mechanism

This domain is centered on the oil's high content of iodine atoms, which serve as the primary physical target for X-ray photons. This interaction is one of photon attenuation; the iodine atoms absorb the X-ray energy, a physical process that produces the radiographic contrast required for detection on imaging detectors.

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Selective Microvascular Retention and Flow Stasis

The mechanism here involves a physical interaction with the structure and dynamics of the target vasculature. The oil's high viscosity and lipophilicity exploit the irregular architecture of certain capillary beds to induce mechanical microembolization and temporary flow stasis. This selective physical trapping, coupled with resistance to rapid clearance by Kupffer cells, results in the prolonged, localized dwelling time of the oil within the microvasculature.

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Inert Carrier Function and Synergistic Delivery

This mechanism establishes the oil as an inert vehicle through physicochemical encapsulation. By forming a stable water-in-oil emulsion with a co-administered drug, the oil’s retention mechanism is leveraged to achieve sustained, high local drug concentration. This synergy contributes to a sustained duration and elevated concentration of the co-administered drug's activity by confining it primarily to the site of physical retention.

How Lipiodol is Used

Lipiodol (Ethiodized Oil) is a sterile oily solution that is administered only via highly specific injection routes, reflecting its specialized role in procedures. Approved routes include selective hepatic intra-arterial injection, intralymphatic injection (for lymphography), and intrauterine/intracavitary injection (for hysterosalpingography). General intravenous or non-selective arterial use is restricted.

Dosage and Schedule

Dosage is defined by volume and the specific area being examined, with administration requiring a controlled clinical environment. For selective hepatic intra-arterial use, dosing ranges from 1.5 mL to 15 mL. The total volume of Lipiodol administered to any patient must not exceed a maximum of 20 mL for a single procedure. The timing of administration can be critical; for example, hysterosalpingography procedures must be performed only during the follicular phase of the menstrual cycle.

Administration Conditions

Administration is to occur under continuous radiologic monitoring, and the injection must proceed slowly. For instance, during intralymphatic injection, the rate must not exceed 0.2 mL per minute. The administration process requires specific equipment, such as the use of a glass syringe, and preparation instructions specify that any mixtures with co-administered drugs must be used promptly (typically within three hours) after preparation. Dose adaptation is required for pediatric patients, where the maximum dose is calculated based on body weight, not exceeding 0.25 mL per kilogram.

Lipiodol: Recent Clinical Evidence

Lipiodol is an established contrast agent used primarily in diagnostic imaging procedures and in therapies for liver cancer, such as transarterial chemoembolization (TACE). Recent clinical evidence continues to focus on its role in improving image-guided delivery and assessing treatment response, particularly in hepatocellular carcinoma (HCC).

Role in Hepatocellular Carcinoma (HCC)

Studies have assessed Lipiodol's performance as a carrier for chemotherapy agents (e.g., doxorubicin) during TACE procedures. The aim of these studies is to evaluate the ability of Lipiodol to retain the chemotherapy drug within the tumor, thereby potentially maximizing the local effect while limiting systemic exposure. Research indicates that the use of Lipiodol-TACE may be associated with tumor response and local disease control in patients with intermediate-stage HCC.

Diagnostic Applications

Lipiodol’s ability to selectively pool in certain tissues has been explored for diagnostic uses, primarily in imaging the liver and lymphatic system. When used in computed tomography (CT) or fluoroscopy, Lipiodol serves to enhance visualization of abnormal tissues or structures.

Research has explored its potential to:

• Improve Visualization: Provide long-lasting opacification (visibility) of the target area, aiding in the assessment of tumor margins.
• Monitor Response: Facilitate the non-invasive assessment of treatment response following TACE by observing the pattern of retention within the treated lesion.

Safety and Tolerability

Clinical trials examining the safety profile of Lipiodol, particularly within TACE regimens, monitor for adverse events. The findings generally suggest that adverse events, such as post-embolization syndrome (fever, pain, nausea), are primarily related to the embolization procedure itself rather than the contrast agent. Patient tolerability is routinely assessed to refine its use in various clinical settings.

Common questions about Lipiodol (FAQ)

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Q: Is Lipiodol only injected directly into the body part being treated?

Official regulatory documents confirm that Lipiodol must only be administered via highly specific, controlled routes of injection. These include selective intra-arterial injection (e.g., to the liver), intralymphatic injection, and intrauterine injection. Its official labeling restricts administration by specific routes, confirming it is not permitted to be given intravenously (into a vein) or intrathecally (into the spine).

Q: Is Lipiodol considered chemotherapy?

No, Lipiodol is not classified as a chemotherapy drug. According to its official product information, it is categorized as a Radiopaque Contrast Agent used for imaging and a Therapeutic Agent Vehicle. This means its primary function is to deliver and localize other drugs, such as chemotherapy, to a specific site during certain procedures like TACE.

Q: How long do the effects of Lipiodol last in the body?

Due to its oily nature, Lipiodol can remain in the body for an extended time. For example, the iodine content can affect the results of thyroid function tests for up to two years following certain procedures. In specific liver procedures, the product's design allows it to remain localized in the tumor for several weeks, which supports the prolonged local therapeutic effect.

Q: What should a patient expect during the procedure where Lipiodol is administered?

Official administration conditions require that the procedure takes place under continuous radiologic monitoring, and the injection must be performed slowly. Patients are monitored closely throughout the injection for signs of discomfort or hypersensitivity. Procedural protocols require that the specialist may stop the injection if pain or excessive discomfort occurs.

Q: Are there long-term health consequences associated with Lipiodol use?

Regulatory documents state that due to the oil’s prolonged retention, the iodine content may interfere with thyroid function, potentially leading to or worsening hyper- or hypothyroidism for up to two years. The label notes that in patients with severe underlying liver disease, administration via the hepatic artery requires careful consideration, as it has been associated with a risk of exacerbating the existing chronic liver condition.

Q: Why is Lipiodol sometimes combined with chemotherapy drugs?

Lipiodol is indicated for use in a procedure called Trans-Arterial Chemo-Embolization (TACE) for certain liver cancers. In this role, it acts as a specialized vehicle to combine with chemotherapy drugs. This combination uses Lipiodol to deliver the medicine directly to the tumor and helps retain it there for a longer period, supporting a sustained local chemotherapy effect.

Q: Does Lipiodol make follow-up imaging scans harder or easier to read?

Lipiodol is designed to aid in the visualization of tumors. Its prolonged retention in the treated lesions allows specialists to clearly identify and localize the areas on follow-up imaging, such as CT scans. Imaging is often performed after 7 to 15 days following selective injection to assess retention in the treated area.

Q: How often do patients typically need follow-up procedures involving Lipiodol?

Official protocols suggest that for procedures like TACE, treatment may be repeated at intervals. The treatment is often repeated every 4 to 8 weeks, with the specific timing determined by the treating healthcare provider based on the patient’s condition and how the tumor has responded.

Q: Can people with shellfish allergies still be given Lipiodol?

Official regulatory information does not list shellfish allergy as a direct contraindication. However, use of Lipiodol is officially contraindicated for individuals with a known hypersensitivity to the medicine or to iodine, given that the product is an iodinated contrast agent.

Q: Is Lipiodol stored differently than regular medications?

Lipiodol has specific requirements for storage to maintain its stability. It must be stored at a controlled room temperature, generally between 15 C and 30 C (59°F and 86°F). Furthermore, it must be kept in its original outer carton to protect it from light until the time it is prepared for use.

Q: Does the dose of Lipiodol change based on the size of the tumor?

Official labeling indicates that for selective hepatic intra-arterial use (such as in TACE), the dose administered is not a fixed amount. The healthcare provider determines the appropriate volume based on the specific extent or size of the lesion or tumor being treated.

Q: Is Lipiodol administered in a hospital setting or can it be done in a clinic?

Due to the specialized nature and specific risks involved, administration for selective hepatic intra-arterial use must be carried out within a typical interventional radiology setting. This requires a specialized clinical environment, such as a hospital or dedicated medical center, with the necessary monitoring equipment.

Q: Why is Lipiodol required to be administered by a specialist like an interventional radiologist?

The official product information specifies that administration for selective hepatic procedures requires a specialized intra-arterial catheterism. This procedure requires specific expertise and is typically performed by a specialist, such as an interventional radiologist, to facilitate the precise and safe delivery of the medicine.

Q: What does 'Lipiodol embolization' mean?

Embolization generally refers to the blockage of a blood vessel. The physical properties of Lipiodol are used to intentionally cause controlled microembolization in tumors, which helps trap the oil and the co-administered drugs. However, the regulatory label warns that its uncontrolled migration can cause serious, unintended embolisms in organs like the lungs or brain.

Q: Is there a generic version of Lipiodol available?

A review of US regulatory filings shows that Lipiodol (Ethiodized Oil) is the Reference Listed Drug (RLD). There are currently no FDA-approved generic equivalents of the product.

Lipiodol Storage and Disposal Requirements

Lipiodol (ethiodized oil) injection must be stored at controlled room temperature, maintaining a specific range between 15 C and 30 C (59 F and 86 F). The product requires protection from light and should remain in its original outer carton until the time of use.

Stability and Handling

Before use, the solution must be visually inspected; it must not be used if the color has darkened or if particulate matter is present. Since Lipiodol is supplied in single-dose ampoules, the solution must be used promptly once drawn into a syringe.

Disposal

Any unused portion of Lipiodol must be discarded. Disposal of the waste product and containers should follow local requirements for medicinal waste.