Pheochromocytoma seen as dark sphere in center of the body (it is in the left adrenal gland). Image is by MIBG scintigraphy, with radiation from radioiodine in the MIBG. Two images are seen of the same patient from front and back. Note dark image of the thyroid due to unwanted uptake of iodide radioiodine from breakdown of the pharmaceutical, by the thyroid gland in the neck. Uptake at the side of the head are from the salivary glands. Radioactivity is also seen in the bladder, from normal renal excretion of iodide.
Therapeutic Class |
Radiopharmaceutical |
Indications |
As an adjunct to other diagnostic tests, in the detection of primary or metastatic pheochromocytoma or neuroblastoma. |
Adult Doses |
Radioimaging: I.V.: 10 mCi (370 MBq) |
Pediatric Doses |
Radioimaging: I.V.: Children 1 month to 16 years and <70 kg: Children <16 years and ≥70 kg: 10 mCi (370 MBq) Children ≥16 years: Refer to adult dosing |
Contraindications |
Hypersensitivity to iobenguane or any component of the formulation. |
Warnings / Precautions |
Use appropriate precautions for handling, disposal, and minimizing exposure to patients and healthcare personnel. Renal impairment: Patients with severe renal impairment may have delayed elimination, therefore, decreasing quality of images. Not dialyzable. Norepinephrine uptake inhibitors: These medications may interfere with the uptake of iobenguane I 123 in neuroendocrine tumors leading to false-negative results.If possible, discontinue prior to iobenguane I 123 administration; allow at least 5 half-lives to elapse. Benzyl alcohol: Contains benzyl alcohol which has been associated with "gasping syndrome" in neonates. Thyroid protective agents (SSKI, Lugol's solution or potassium iodide), should be given at least 1 hour prior to administration.Ensure adequate hydration before and after treatment. |
Adverse Reactions |
Dizziness, flushing, hypersensitivity (rare), injection site hemorrhage, pruritus, rash. |
Food Interactions |
Some dietary sources of iodine include cow's milk and dairy products, fish, seaweed, eggs, chocolate, and iodized salt. |
Mechanism of Actions |
Iobenguane is structurally similar to norepinephrine and therefore is taken up and stored in adrenergic tissue such as adrenal medulla, heart, liver, lungs, salivary glands, and spleen. Iobenguane is bound to radioactive iodine in order to obtain organ and tissue images |
Pharmacodynamics |
Distribution: Increased in adrenergically innervated tissues (eg, heart, salivary glands, adrenal medulla) Metabolism: Has not been characterized Half-life elimination: Iodine 123: 13.2 hours Excretion: Urine (70 % to 90%) within 4 days (normal renal function); feces <1% |
Monitoring |
Pulse and blood pressure prior to administration and intermittently for 30 minutes following; monitor for hypersensitivity reaction. |
Administration |
Thyroid protective agents (SSKI, Lugol's solution or potassium iodide), should be given at least 1 hour prior to administration.Perform whole body planar scintigraphy imaging 18-30 hours after Iobenguane I 123 administration.Ensure adequate hydration before and after treatment. |
Pregnancy Category |
C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks. |
Lactation |
Excretion in breast milk unknown/not recommended. |
ATC Classification |
V09IX01,V09IX02,V10XA02 |
GenericPedia Classification |
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