Iobenguane I 123

Iobenguane I 123 is used for detection of primary or metastatic pheochromocytoma or neuroblastoma as an adjunct to other diagnostic tests and for assessment of myocardial sympathetic innervation in patients with NYHA class 2-3 heart failure with an LVEF less than 35%; among these patients, may help identify those with lower 1- and 2- year mortality risks as indicated by a H/M ratio 1.6 or greater.

Iobenguane I 123 is available under the following different brand names: AdreView.

Dosages of Iobenguane I 123:

Dosage Forms and Strengths

Intravenous (IV) Solution

• 2mCi/mL at calibration time (0.08mg/mL iobenguane sulfate 74 MBq/mL of I 123)

Dosage Considerations – Should be Given as Follows:

Gamma Scintigraphy

Diagnostic radiopharmaceutical agent for gamma-scintigraphy

Pheochromocytoma or neuroblastoma

• Indicated for detection of primary or metastatic pheochromocytoma or neuroblastoma as an adjunct to other diagnostic tests
• 10 mCi (5 mL; 370 MBq) intravenously (IV)
• Begin whole-body planar scintigraphy imaging 24 ± 6 hours following administration

Congestive heart failure

• Indicated for assessment of myocardial sympathetic innervation in patients with NYHA class 2-3 heart failure with an LVEF less than 35%; among these patients, may help identify those with lower 1- and 2-year mortality risks as indicated by an H/M ratio 1.6 or greater
• 10 mCi (5 mL; 370 MBq) IV (2 mCi/mL at calibration time)
• Begin anterior planar imaging of the chest at 4 hours (± 10 minutes) following administration

Children under 16 years and 70 kg or greater: 10 mCi (5 mL; 370 MBq)

Children under 16 years (3-18 kg)

• 3 kg: 1 mCi (37 MBq)
• 4 kg: 1.4 mCi (52 MBq)
• 6 kg: 1.9 mCi (70 MBq)
• 8 kg: 2.3 mCi (85.1 MBq)
• 10 kg: 2.7 mCi (99.9 MBq)
• 12 kg: 3.2 mCi (118.4 MBq)
• 14 kg: 3.6 mCi (133.2 MBq)
• 16 kg: 4 mCi (148 MBq)
• 18 kg: 4.4 mCi (162.8 MBq)

Children under 16 years (20-40 kg)

• 20 kg: 4.6 mCi (170.2 MBq)
• 22 kg: 5 mCi (185 MBq)
• 24 kg: 5.3 mCi (196.1 MBq)
• 26 kg: 5.6 mCi (207.2 MBq)
• 28 kg: 5.8 mCi (214.6 MBq)
• 30 kg: 6.2 mCi (229.4 MBq)
• 32 kg: 6.5 mCi (240.5 MBq)
• 34 kg: 6.8 mCi (251.6 MBq)
• 36 kg: 7.1 mCi (262.7 MBq)
• 38 kg: 7.3 mCi (270.1 MBq)
• 40 kg: 7.6 mCi (281.2 MBq)

Children under 16 years (42-50 kg)

• 42 kg: 7.8 mCi (288.6 MBq)
• 44 kg: 8 mCi (296 MBq)
• 46 kg: 8.2 mCi (303.4 MBq)
• 48 kg: 8.5 mCi (314.5 MBq)
• 50 kg: 8.8 mCi (325.6 MBq)

Children under 16 years (52 kg to less than 70 kg)

• 52-54 kg: 9 mCi (333 MBq)
• 56-58 kg: 9.2 mCi (340.4 MBq)
• 60-62 kg: 9.6 mCi (355.2 MBq)
• 64-66 kg: 9.8 mCi (362.6 MBq)
• 68 kg: 9.9 mCi (366.3 MBq)

Neonates under 1 month: Safety and efficacy not established

Administration

• Administer IV over 1-2 minutes, then flush with 0.9% NaCl to ensure full dose delivery

Radiation safety

• Emits radiation and must be handled with appropriate safety measures to minimize radiation exposure to clinical personnel and patients
• Minimize bladder exposure by encouraging hydration before and after to permit frequent voiding, particularly for the first 48 hours after administration

Thyroid blockade

• Administer potassium iodide oral solution or Lugol’s solution (equivalent to 100 mg iodide for adults, body-weight adjusted for children) or potassium perchlorate (400 mg for adults, body-weight adjusted for children) to block uptake of iodine 123 by the patient’s thyroid
• Individualize according to the patient; blockade may not be needed for patients who have undergone thyroidectomy or those with a limited life expectancy

Side effects of iobenguane I 123 include:

• Dizziness
• Rash
• Itching
• Flushing
• Injection site bleeding

Postmarketing side effects of iobenguane I 123 reported include:

• Hypersensitivity

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Iobenguane I 123 has severe interactions with at least 32different drugs.
• Serious interactions of iobenguane I 123 include:
  • methylphenidate
• Iobenguane I 123 has no listed moderate interactions with other drugs.
• Iobenguane I 123 has no listed mild interactions with other drugs.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

Warnings

• This medication contains iobenguane I 123. Do not take AdreView if you are allergic to iobenguane I 123 or any ingredients contained in this drug.
• Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.

Contraindications

• Hypersensitivity

Effects of Drug Abuse

• No information available

Short-Term Effects

• See "What Are Side Effects Associated with Using Iobenguane I 123?”

Long-Term Effects

• See "What Are Side Effects Associated with Using Iobenguane I 123?”

Cautions

• Emits radiation and must be handled with appropriate safety measures for radiopharmaceuticals
• Fully investigate the history of an allergic response to previous contrast agents or iodine
• Contains benzyl alcohol (10.3 mg/mL); associated with fatal gasping syndrome in premature infants and infants of low birth weight; excessive amounts associated with toxicity (low blood pressure, metabolic acidosis), particularly in neonates, and increased incidence of kernicterus in small preterm infants
• Increased radiation exposure in patients with severe renal impairment; cleared by glomerular filtration and is not dialyzable
• Failure to block thyroid uptake of iodine 123 may result in an increased long-term risk for thyroid neoplasia; administer thyroid blocking medications
• Drugs that interfere with norepinephrine uptake or retention may cause false-negative imaging results; if clinically feasible, discontinue these drugs before administering iobenguane I 123
• Individuals with conditions that affect the sympathetic nervous system (e.g., Parkinson disease, multiple system atrophy) may show decreased cardiac uptake of iobenguane I 123 independent of heart disease
• Assess pulse and blood pressure before and intermittently for 30 minutes following administration

Pregnancy and Lactation

• Radioactive iodine products such as iobenguane I 123 cross the placenta and can permanently impair fetal thyroid function. Administration of an appropriate thyroid blocking agent is recommended before use in a pregnant woman to protect the woman and fetus from the accumulation of I 123. There are no available data on use in pregnant women to evaluate for a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes.
• Iobenguane I 123 contains 10.3 mg/mL of benzyl alcohol. Because benzyl alcohol is rapidly metabolized by a pregnant woman, benzyl alcohol exposure in the fetus is unlikely; however, adverse reactions have occurred in premature neonates and low birth weight infants who received intravenously administered benzyl alcohol-containing drugs. Consult your doctor.
• Iodine 123 (I 123), the radionuclide in the drug, is present in human milk. There is no information on the effects on breastfed infants or milk production. Lactating women are advised to interrupt breastfeeding and pump and discard breastmilk for at least 6 days (more than 10 physical half-lives) after administration to minimize radiation exposure to a breastfed infant.