INDIUM IN 111 OXYQUINOLINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for INDIUM IN 111 OXYQUINOLINE (INDIUM IN 111 OXYQUINOLINE).
Indium In 111 oxyquinoline is a radiolabeled compound that chelates indium-111 with oxyquinoline. The lipophilic complex penetrates cell membranes and binds to intracellular components, primarily in leukocytes (neutrophils). After intravenous injection, the radiolabeled cells accumulate at sites of inflammation or infection, allowing gamma camera imaging to detect focal areas of abnormal leukocyte localization.
| Metabolism | Indium In 111 oxyquinoline is not metabolized. The indium-111 radionuclide decays by electron capture to stable cadmium-111 with a physical half-life of 2.83 days. The oxyquinoline ligand is released intracellularly and undergoes hepatic metabolism to glucuronide conjugates, which are excreted in urine and feces. |
| Excretion | Renal excretion approximately 70-80% within 24 hours; fecal excretion less than 5%. |
| Half-life | Terminal elimination half-life is approximately 4-6 hours for the free indium ion, but biological half-life for labeled cells can be 1-2 days depending on cell type. |
| Protein binding | Approximately 90% bound to plasma proteins, primarily transferrin and lactoferrin. |
| Volume of Distribution | Vd approximately 0.3 L/kg for indium-111 labeled cells; reflects distribution primarily in blood pool and bone marrow. |
| Bioavailability | Intravenous only; bioavailability 100%. |
| Onset of Action | Intravenous injection: Radiolabeled cells distribute rapidly; imaging can begin within 1-4 hours post-injection. |
| Duration of Action | Effective imaging window: 4-24 hours post-injection. For abscess detection, imaging at 18-24 hours is optimal due to background clearance. |
1-2 mCi (37-74 MBq) labeled autologous leukocytes, administered intravenously over 1-2 minutes.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for renal impairment; however, prolonged blood pool activity may occur in severe impairment. |
| Liver impairment | No adjustment required; drug is minimally metabolized by the liver. |
| Pediatric use | 0.05-0.15 mCi/kg (1.85-5.55 MBq/kg) intravenously; maximum 2 mCi (74 MBq). |
| Geriatric use | Same as adult dose; monitor for prolonged retention due to age-related reduced clearance. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for INDIUM IN 111 OXYQUINOLINE (INDIUM IN 111 OXYQUINOLINE).
| Breastfeeding | Significant radiation exposure to the infant may result from breastfeeding. The manufacturer recommends discontinuing breastfeeding after administration due to radioactivity. Advise pump and discard breast milk for at least 2 weeks (10 half-lives of In-111) to reduce infant exposure. Specific M/P ratio not available. |
| Teratogenic Risk | Indium In 111 oxyquinoline is a radioactive diagnostic agent. Pregnancy category D. There is positive evidence of human fetal risk, but the benefits from use in pregnant women may be acceptable despite the risk in certain conditions (e.g., life-threatening situations or serious diseases for which safer drugs cannot be used or are ineffective). Radiation exposure from the procedure may cause fetal harm. Use in pregnancy only if clearly needed and potential benefit justifies potential risk to fetus. No trimester-specific data available; risks apply throughout pregnancy due to ionizing radiation. |
■ FDA Black Box Warning
None
| Serious Effects |
["Absolute: Known hypersensitivity to indium In 111 oxyquinoline or any component of the formulation.","Relative: Pregnancy (unless potential benefit justifies risk); lactation; patients with severely compromised bone marrow or leukopenia (may affect image quality)."]
| Precautions | ["Radiation exposure: Risk of secondary malignancies; limit use to necessary indications.","Allergic reactions: Hypersensitivity to oxyquinoline or indium compounds may occur.","Cell labeling efficacy: Inadequate leukocyte labeling can affect image quality; verify labeling efficiency.","Administration precautions: Use aseptic technique; avoid extravasation.","Pregnancy: Category D (known fetal risk); use only if benefit outweighs risk.","Lactation: Discontinue nursing for 24-48 hours after administration."] |
| Food/Dietary | No specific food interactions. Maintain adequate hydration to facilitate renal excretion of the radiopharmaceutical. |
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| Fetal Monitoring | No specific monitoring required beyond standard radiation safety precautions. Confirm absence of pregnancy before administration. If pregnancy cannot be excluded, consider alternative non-radioactive imaging. Post-administration, monitor for injection site reactions. No fetal monitoring indicated. |
| Fertility Effects | Potential adverse effects on fertility due to radiation exposure. Animal studies not available; however, ionizing radiation can cause gonadal damage and impair fertility. Use with caution in patients of reproductive potential. |
| Clinical Pearls | Indium-111 oxyquinoline is used for radiolabeling autologous leukocytes for infection/inflammation imaging. Handle with sterile technique; cell labeling must be validated for viability. Administer promptly after preparation due to short half-life (2.8 days). Image acquisition typically at 24 h post-injection. Contraindicated in patients with hypersensitivity to oxyquinoline or egg white proteins (if using albumin-containing kits). |
| Patient Advice | This medication is a radioactive agent used to help detect infection or inflammation in the body. · You will receive an injection of your own white blood cells that have been labeled with a small amount of radioactive material. · The procedure takes about 2 hours for blood collection, labeling, and reinjection. · You may need to wait 24 hours after injection before imaging is performed. · Drink plenty of fluids to help clear the radioactive material from your body. · Inform your healthcare provider if you are pregnant, breastfeeding, or have allergies to eggs or oxyquinoline. · You will be exposed to a small amount of radiation, which is considered safe for diagnostic purposes. |