AdreView

Name: AdreView

What is iobenguane I-123?

Iobenguane I-123 is in a group of drugs called diagnostic radiopharmaceuticals (RAY dee oh far ma SOO tik als). Iobenguane I-123 is a radioactive agent that allows images of specific organs in the body to be detected by a gamma camera.

Iobenguane I-123 is used to detect certain kinds of tumors.

Iobenguane I-123 is also used in people with congestive heart failure to assess the function of nerves that control the heart muscle. Iobenguane I-123 can detect nerve damage to help identify a patient's risk of death from heart failure.

Iobenguane I-123 may also be used for purposes not listed in this medication guide.

What should I avoid while receiving iobenguane I-123?

Do not allow yourself to become dehydrated during the first few days after receiving iobenguane I-123. Call your doctor if you have any vomiting or diarrhea during this time. Follow your doctor's instructions about the types and amount of fluids you should drink.

AdreView Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

Incidence not known
  • Difficulty breathing or swallowing
  • fast heartbeat
  • fever
  • hives
  • hoarseness
  • irritation
  • itching
  • joint pain, stiffness, or swelling
  • nausea
  • rash
  • reddening of the skin, especially around the ears
  • swelling of the eyes, face, or inside of the nose
  • tightness in the chest
  • unusual tiredness or weakness

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common
  • Bleeding, blistering, bruising, burning, coldness, discoloration of the skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
  • dizziness
  • feeling of warmth or redness of the face, neck, arms, and occasionally, upper chest
Rare
  • Headache

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Consumer Information Use and Disclaimer

  • If your symptoms or health problems do not get better or if they become worse, call your doctor.
  • Do not share your drugs with others and do not take anyone else's drugs.
  • Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
  • Talk with the doctor before starting any new drug, including prescription or OTC, natural products, or vitamins.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Check with your pharmacist about how to throw out unused drugs.
  • Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about this medicine, please talk with your doctor, nurse, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

This information should not be used to decide whether or not to take AdreView or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to AdreView. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Review Date: October 4, 2017

Contraindications

AdreView is contraindicated in patients with known hypersensitivity to iobenguane or iobenguane sulfate.

AdreView - Clinical Pharmacology

Mechanism of Action

Iobenguane is similar in structure to the antihypertensive drug guanethedine and to the neurotransmitter norepinephrine (NE). Iobenguane is, therefore, largely subject to the same uptake and accumulation pathways as NE. Iobenguane is taken up by the NE transporter in adrenergic nerve terminals and stored in the presynaptic storage vesicles. Iobenguane accumulates in adrenergically innervated tissues such as the adrenal medulla, salivary glands, heart, liver, spleen and lungs as well as tumors derived from the neural crest. By labeling iobenguane with the isotope iodine 123, it is possible to obtain scintigraphic images of the organs and tissues in which the radiopharmaceutical accumulates.

Pharmacodynamics

AdreView is a diagnostic radiopharmaceutical which contains a small quantity of iobenguane that is not expected to produce a pharmacodynamic effect [see Description (11)]. To minimize radiation dose to the thyroid gland, this organ should be blocked before dosing [see Dosage and Administration (2.1)]. Since iobenguane is excreted mainly via the kidneys, patients with severe renal insufficiency may experience increased radiation exposure and impaired imaging results. Frequent voiding should be encouraged after administration to minimize the radiation dose to the bladder [see Warnings and Precautions (5.3)]. The calculation of the estimated radiation dose is shown in Table 2 [see Dosage and Administration (2.5)].

Pharmacokinetics

Iobenguane is rapidly cleared from the blood and accumulates in adrenergically innervated tissues [see Clinical Pharmacology (12.1)]. Retention is especially prolonged in highly adrenergically innervated tissues (e.g., the adrenal medulla, heart, and salivary glands).

The majority of the iobenguane dose is excreted unaltered by the kidneys via glomerular filtration. A rapid initial clearance of circulating iobenguane is observed, followed by a slow clearance as iobenguane is released from other compartments. In patients with normal renal function, 70 to 90% of the administered dose is recovered unaltered in urine within 4 days. Iobenguane is not cleared by dialysis [see Warnings and Precautions (5.3)]. Most of the remaining radioactivity recovered in the urine is in the form of the radioiodinated metabolite m-iodohippuric acid (MIHA) (typically ≤ 10%) and free radioiodide (typically ≤ 6%). The enzymatic process responsible for metabolism has not been well characterized and the pharmacologic activity of these metabolites has not been studied. Only a small amount (< 1%) of the injected dose is eliminated via the feces.

Clinical Studies

Pheochromocytomas and Neuroblastomas

The safety and efficacy of AdreView were assessed in an open-label, multicenter, multinational trial of 251 subjects with known or suspected neuroblastoma or pheochromocytoma. Diagnostic efficacy for the detection of metabolically active neuroblastoma or pheochromocytoma was determined by comparison of focal increased radionuclide uptake on planar scintigraphy at 24 ± 6 hours post-administration of AdreView against the definitive diagnosis (standard of truth). Anterior and posterior planar whole-body images, or alternatively whole-body overlapping spot images, were acquired from the head to below the knees. Additional spot images were performed as deemed appropriate at the discretion of the clinical image reviewer. SPECT imaging of the thorax and abdomen was then obtained when possible.

Of the 251 subjects dosed with AdreView, 100 had known or suspected neuroblastoma and 151 had known or suspected pheochromocytoma. The population included 154 adults and 97 pediatric patients; the majority of adults were female (59%), the majority of pediatric subjects were male (58%). The adult subjects had a mean age of 49 years (range 17 to 88 years). The pediatric patients (56 males and 41 females) consisted of 32 infants (1 month up to 2 years of age), 62 children (2 years up to 12 years) and three adolescents (12 years up to 16 years).

The definitive diagnosis (standard of truth) for the presence or absence of metabolically active pheochromocytoma or neuroblastoma was determined by histopathology or, when histopathology was unavailable, a composite of imaging (i.e., CT, MRI, [131I]-mIBG scintigraphy), plasma/urine catecholamine and/or catecholamine metabolite measurements, and clinical follow-up.

A standard of truth was available for 211 subjects (127 with pheochromocytoma, 84 with neuroblastoma) and this group comprised the diagnostic efficacy population. For 93 of these subjects, the standard of truth was based solely upon histopathology. Of 211 subjects in the efficacy population, all had planar scintigraphy and 167 subjects had SPECT in addition to planar imaging. All images were assessed independently by three readers blinded to all clinical data. Table 5 summarizes the AdreView performance characteristics, by reader.

Table 5. AdreView Planar Imaging: Sensitivity and Specificity
Outcome Reader A Reader B Reader C
Sensitivity (n = 159)
Point estimate 0.80 0.77 0.79
95% confidence interval 0.73 - 0.86 0.70 - 0.84 0.71 - 0.85
Specificity (n = 52)
Point estimate 0.77 0.73 0.69
95% confidence interval 0.63 - 0.87 0.59 - 0.84 0.55 - 0.81

Performance characteristics (sensitivity and specificity) of AdreView planar imaging in patients with known or suspected neuroblastoma were similar to those in patients with known or suspected pheochromocytoma. Among the selected patients who also underwent SPECT imaging, similar performance characteristics of AdreView scintigraphy were observed when SPECT plus planar imaging was compared to planar imaging alone.

What other drugs will affect AdreView?

Some medicines can interfere with the quality of images produced by AdreView. Tell your doctor about all your current medicines and any you recently stopped using, especially:

  • an antidepressant such as amitriptyline, bupropion, citalopram, desipramine, fluoxetine, imipramine, paroxetine, sertraline, Wellbutrin, Zoloft, Prozac, Celexa, and others;

  • blood pressure medication; or

  • cough, cold, or allergy medicine that contains a decongestant (phenylephrine or pseudoephedrine).

This list is not complete. Other drugs may interact with iobenguane I-123, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

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