Version July 2025
Note: Thyroid blockade and other pre- and concomitant medications are recommended.
Pheochromocytoma or paraganglioma (unresectable, locally advanced or metastatic): IV:
Dosimetric dose:
>50 kg: 185 to 222 MBq (5 or 6 mCi)
≤50 kg: 3.7 MBq/kg (0.1 mCi/kg)
Dosimetry, distribution assessment, and critical organ threshold values: Refer to the manufacturer’s labeling for detailed information.
Therapeutic dose: The recommended therapeutic dose is based on body weight and reduced (if necessary) based on the dosimetric data. Administer a total of 2 therapeutic doses, with at least 90 days in between the 2 doses.
>62.5 kg: 18,500 MBq (500 mCi)
≤62.5 kg: 296 MBq/kg (8 mCi/kg)
Dose reduction (if needed) based on critical organ limits: Calculate the estimated critical organ absorbed-dose by multiplying the dosimetry-derived radiation absorbed-dose per unit activity [D (organ)] by weight based therapeutic total activity (Aw). Refer to the manufacturer's labeling for additional details/information.
Premedications and concomitant medications:
Antiemetics: Administer antiemetics 30 minutes prior to administering each iobenguane I 131 dose.
Hydration: Instruct patients to increase fluid intake to at least 2 liters/day starting at least 1 day prior to each iobenguane I 131 dose; continue for 1 week following each iobenguane I 131 dose to minimize bladder exposure.
Thyroid blockade: Administer inorganic iodine beginning at least 24 hours prior to each iobenguane I 131 dose; continue for 10 days following each iobenguane I 131 dose.
Medications which reduce catecholamine uptake or deplete stores: Discontinue medications which reduce catecholamine uptake or deplete catecholamine stores for at least 5 half-lives prior to administration of either the iobenguane I 131 dosimetry dose or a therapeutic dose. Do not administer these medications until at least 7 days after each iobenguane I 131 dose.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Adjust the therapeutic dose based on radiation exposure estimates from dosimetry assessment.
Adjust the therapeutic dose based on radiation exposure estimates from dosimetry assessment.
Hematologic toxicity:
First therapeutic dose: ANC <1,200/mm3 or platelets <80,000/mm3: Do not administer the first iobenguane I 131 therapeutic dose.
Second therapeutic dose: Do not administer the second therapeutic dose until platelets and neutrophils return to baseline or normal. Reduce the second therapeutic dose for platelets <25,000/mm3 (or <50,000/mm3 with active bleeding), ANC <500/mm3, life-threatening anemia lasting >7 days, or febrile neutropenia.
Dose reduction levels for hematologic toxicity (for second therapeutic dose):
Patients >62.5 kg: If the first therapeutic dose was weight-based, reduce the second therapeutic dose to 425 mCi. If the first therapeutic dose was reduced based on critical organ limits, reduce the second therapeutic dose to 85% of the first therapeutic dose.
Patients ≤62.5 kg: If the first therapeutic dose was weight-based, reduce the second therapeutic dose to 7 mCi/kg. If the first therapeutic dose was reduced based on critical organ limits, reduce the second therapeutic dose to 85% of the first therapeutic dose.
Nonhematologic toxicity: Pneumonitis: If pneumonitis is diagnosed after the first therapeutic dose, do not administer the second therapeutic dose.
Refer to adult dosing.
(For additional information see "Iobenguane I-131 (therapeutic) (United States and Canada: Not available): Pediatric drug information")
Note: Use under the supervision of a qualified physician experienced in the use of radiopharmaceuticals.
Pheochromocytoma or paraganglioma (unresectable, locally advanced or metastatic): Note: Thyroid blockade and other pre- and concomitant medications are recommended. Children ≥12 years and Adolescents: IV:
Dosimetric dose:
≤50 kg: 3.7 MBq/kg (0.1 mCi/kg)
>50 kg: 185 to 222 MBq (5 or 6 mCi)
Dosimetry and distribution assessment:
Scanning: Acquire anterior/posterior whole-body gamma camera images within 1 hour of the iobenguane I 131 dosimetric dose and prior to patient voiding (day 0; scan 1). Acquire additional images on day 1 or 2 following patient voiding (scan 2). Acquire additional images between days 2 to 5 following patient voiding (scan 3).
Assessment: Calculate the radiation dose estimates to normal organs and tissues per unit activity (D [organ]) of administered dose (for each individual patient) using data extracted from the 3 scanning images. Calculate in accordance with the Medical Internal Radiation Dose (MIRD) schema or related methodology. Whenever possible, use patient-specific organ masses (eg, estimated from imaging).
Therapeutic dose: The recommended therapeutic dose is based on body weight and reduced (if necessary) based on the dosimetric data. Administer a total of 2 therapeutic doses, with at least 90 days in between the 2 doses.
≤62.5 kg: 296 MBq/kg (8 mCi/kg)
>62.5 kg: 18,500 MBq (500 mCi)
Dose reduction (if needed) based on critical organ limits: Calculate the estimated critical organ absorbed-dose by multiplying the dosimetry-derived radiation absorbed-dose per unit activity (D [organ]) by weight based therapeutic total activity (Aw).
If resulting estimated critical organ absorbed-dose is less than threshold absorbed-dose (T) shown in the table: No dose adjustment is necessary.
If resulting estimated critical organ absorbed-dose exceeds threshold absorbed-dose (T) shown in the following absorbed-dose threshold value table, calculate the reduced therapeutic total activity (ie, the cumulative activity that would be administered in 2 therapeutic cycles) using the following equation:
Reduced Therapeutic Total Activity = Aw × (T ÷ [Aw × D {organ}])
|
Organ |
~1%-rate mortality or organ failure associated with disease |
Time to death or organ failure |
Threshold* absorbed-dose for ~1% mortality or organ failure (Gy) |
|---|---|---|---|
|
*Threshold of ~0.5 Gy for both heart and carotid artery, derived from experience with external-beam radiotherapy and associated with fractionated exposure, has also been proposed to support an ~1% mortality rate of cardiovascular and cerebrovascular deaths in >10 to 15 years; however, uncertainty is associated with the value ~0.5 Gy cited for vascular disease. Consider benefits/risks to patients. | |||
|
Red marrow |
H-ARS mortality |
1 to 2 months |
12 |
|
Lungs |
Pneumonitis mortality |
1 to 7 months |
16.5 |
|
Kidney |
Renal failure |
>1 year |
18 |
|
Liver |
Hepatomegaly, ascites: Possible organ failure |
0.5 to 3 months |
31 |
|
Small intestine |
GI-ARS mortality |
6 to 9 days |
40 |
Premedications and concomitant medications:
Thyroid blockade: Administer inorganic iodine beginning at least 24 hours prior to each iobenguane I 131 dose; continue for 10 days following each iobenguane I 131 dose.
Hydration: Instruct patients to increase fluid intake to at least 2 liters/day starting at least 1 day prior to each iobenguane I 131 dose; continue for 1 week following each iobenguane I 131 dose to minimize bladder exposure.
Antiemetics: Administer antiemetics 30 minutes prior to administering each iobenguane I 131 dose.
Medications which reduce catecholamine uptake or deplete stores: Discontinue medications that reduce catecholamine uptake or deplete catecholamine stores for at least 5 half-lives prior to administration of either the iobenguane I 131 dosimetry dose or a therapeutic dose. Do not administer these medications until at least 7 days after each iobenguane I 131 dose.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Dosing adjustment for toxicity: Children ≥12 years and Adolescents: IV:
Hematologic toxicity:
First therapeutic dose: ANC <1,200/mm3 or platelets <80,000/mm3: Do not administer the first iobenguane I 131 therapeutic dose.
Second therapeutic dose: Do not administer the second therapeutic dose until platelets and neutrophils return to baseline or normal. Reduce the second therapeutic dose for platelets <25,000/mm3 (or <50,000/mm3 with active bleeding), ANC <500/mm3, life-threatening anemia lasting >7 days, or febrile neutropenia.
Dose reduction levels for hematologic toxicity (for second therapeutic dose):
Patients ≤62.5 kg: If the first therapeutic dose was weight-based, reduce the second therapeutic dose to 7 mCi/kg. If the first therapeutic dose was reduced based on critical organ limits, reduce the second therapeutic dose to 85% of the first therapeutic dose.
Patients >62.5 kg: If the first therapeutic dose was weight-based, reduce the second therapeutic dose to 425 mCi. If the first therapeutic dose was reduced based on critical organ limits, reduce the second therapeutic dose to 85% of the first therapeutic dose.
Non-hematologic toxicity: Pneumonitis: If pneumonitis is diagnosed after the first therapeutic dose, do not administer the second therapeutic dose.
Children ≥12 years and Adolescents: Patients with renal impairment have delayed elimination that may result in an increased radiation exposure; adjust the therapeutic dose based on radiation exposure estimates from dosimetry assessment. The safety of iobenguane I 131 has not been studied in patients with CrCl <30 mL/minute or end-stage renal disease.
There are no dosage adjustments provided in the manufacturer's labeling; however, iobenguane I 131 does not undergo hepatic metabolism. Adjust the therapeutic dose based on radiation exposure estimate from dosimetry assessment.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.
>10%:
Cardiovascular: Hypotension (24%), hypertension (20%)
Central nervous system: Fatigue (71%), dizziness (34%), headache (32%)
Endocrine & metabolic: Dehydration (16%), weight loss (16%)
Gastrointestinal: Nausea (78%), vomiting (58%), xerostomia (48%), sialadenitis (39%), decreased appetite (30%), diarrhea (25%), dysgeusia (24%), abdominal pain (23%), constipation (19%)
Genitourinary: Decreased estimated GFR (eGFR) (22%), urinary tract infection (11%)
Hematologic & oncologic: Lymphocytopenia (96%, grades 3/4: 78%), anemia (93%; grades 3/4: 24%), thrombocytopenia (91%, grades 3/4: 50%), increased INR (85%, grades 3/4: 18%), neutropenia (84%, grades 3/4: 59%)
Hepatic: Increased serum alkaline phosphatase (53%), increased serum aspartate aminotransferase (50%), increased serum alanine aminotransferase (43%)
Neuromuscular & skeletal: Back pain (17%), limb pain (15%)
Respiratory: Cough (18%), dyspnea (18%), upper respiratory tract infection (16%), oropharyngeal pain (14%)
Miscellaneous: Fever (14%)
1% to 10%:
Cardiovascular: Tachycardia (10%), orthostatic hypotension (9%), palpitations (9%), presyncope (≤8%), syncope (≤8%), chest pain (6%), pulmonary embolism (3%)
Central nervous system: Insomnia (9%), chills (8%)
Dermatologic: Alopecia (10%), hyperhidrosis (10%), skin rash (8%), xeroderma (8%)
Endocrine & metabolic: Thyroid stimulating hormone suppression (5%), hypothyroidism (3%)
Gastrointestinal: Dyspepsia (10%), dysphagia (7%), abdominal distention (6%), gastroesophageal reflux disease (6%), stomatitis (3%)
Genitourinary: Proteinuria (9%)
Hematologic & oncologic: Prolonged prothrombin time (9%), myelodysplastic syndrome (7%), petechia (7%), febrile neutropenia (5%)
Infection: Cutaneous candidiasis (6%)
Local: Pain at injection site (10%)
Neuromuscular & skeletal: Arthralgia (8%), neck pain (8%), jaw pain (7%), muscle spasm (6%)
Renal: Renal failure syndrome (7%)
Respiratory: Epistaxis (9%), nasal congestion (7%)
<1%, postmarketing, and/or case reports: Adenocarcinoma, malignant neoplasm of colon, pneumonitis
There are no contraindications listed in the manufacturer's labeling.
Concerns related to adverse effects:
• Bone marrow suppression: The iobenguane I 131 therapeutic dose is associated with severe and prolonged myelosuppression, including grade 4 lymphopenia, anemia, neutropenia, and thrombocytopenia. Neutropenic fever has occurred. Following the first therapeutic dose, the grade 4 neutrophil nadir occurred at a median of 36 days (range: 27 to 55 days) and remained at nadir for a median of 12 days (range: 8 to 22 days) until recovery to grade 3 or lower. Grade 4 neutropenia reached nadir following the second therapeutic dose at a median of 43 days (range: 38 to 47 days) and remained at nadir for a median of 18.5 days (range: 8 to 31 days) until recovery to grade 3 or lower. Monitor blood cell counts weekly for up to 12 weeks or until return to baseline or normal range. Hematologic toxicity may require treatment interruption or dose reduction based on severity of the cytopenia.
• Hypertension: Worsening preexisting hypertension (defined as a systolic blood pressure increase to ≥160 mm Hg with an increase of 20 mm Hg or a diastolic blood pressure increase to ≥100 mm Hg with an increase of 10 mm Hg) has occurred with the therapeutic dose. Blood pressure changes occurred within the first 24 hours after the infusion. Monitor blood pressure frequently during the first 24 hours after each therapeutic dose.
• Hypothyroidism: Hypothyroidism has been reported with the therapeutic dose. The onset for development or worsening of hypothyroidism ranged from <1 month to 18 months. Initiate thyroid-blocking medications beginning at least 1 day before and continuing for 10 days after each dose (dosimetric and therapeutic) to reduce the risk of hypothyroidism or thyroid neoplasia. Evaluate for clinical evidence of hypothyroidism and monitor thyroid-stimulating hormone (TSH) levels prior to treatment initiation and then annually thereafter, or as clinically indicated. Some resources suggest monitoring TSH every 6 months for life (Hamnvik 2011).
• Gastrointestinal toxicity: May cause nausea, vomiting, xerostomia, diarrhea, and abdominal pain. Antiemetics are recommended prior to administration.
• Pneumonitis: Fatal pneumonitis occurred 9 weeks after a single dose in 1 patient (in an expanded access program); however, pneumonitis was not diagnosed among the patients enrolled in 2 clinical studies. Monitor for signs and symptoms of pneumonitis and manage appropriately.
• Renal toxicity: Renal failure, acute kidney injury, and/or a clinically significant decrease in glomerular filtration rate (GFR) (at 6 or 12 months) have occurred with iobenguane I 131. Monitor renal function during and after treatment. Patients with baseline renal impairment may be at greater risk of renal toxicity; perform more frequent renal function assessments in patients with mild or moderate renal impairment. The radiation dose may be increased (due to delayed elimination) in patients with renal impairment. Iobenguane I 131 has not been studied in patients with severe renal impairment (CrCl <30 mL/minute) or end stage renal disease.
• Secondary malignancies: Myelodysplastic syndromes (MDS) or acute leukemias have been reported in patients who received a therapeutic iobenguane I 131 dose. The time to development of MDS or acute leukemia ranged from 12 months to 7 years. Nonhematological malignancies (colon cancer, lung cancer) have also been reported (rare) following the first therapeutic dose. Iobenguane I 131 contributes to a patient's overall long-term radiation exposure. Long-term cumulative radiation exposure is associated with an increased risk for cancer. These risks of radiation associated with the use of iobenguane I 131 are higher in pediatric patients than in adults.
Special handling:
• Radiopharmaceutical: Use appropriate precautions for handling, disposal, and minimizing exposure to patients, health care personnel, and household contacts. Use only under supervision of individuals with experience/training in the handling of radioactive materials approved by the applicable regulatory authority. Consistent with institutional good radiation safety practices and patient management procedures, minimize radiation exposure to patients, medical personnel, and household contacts during and after treatment.
The risks of radiation associated with iobenguane I 131 is greater in pediatric patients compared to adults due to the larger absorbed radiation doses and longer life expectancy; ensure benefits outweigh risks prior to administration.
In August 2023, Progenics Pharmaceuticals, Inc., announced the decision to discontinue the production and promotion of Azedra with plans to continue manufacturing into the first quarter of 2024.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Solution, Intravenous:
Azedra Dosimetric: 555 MBq/mL (15 mCi/mL) (1 ea [DSC])
Azedra Therapeutic: 555 MBq/mL (15 mCi/mL) (1 ea [DSC])
No
Solution (Azedra Dosimetric Intravenous)
15 mci/mL (per each): $11,534.04
Solution (Azedra Therapeutic Intravenous)
15 mci/mL (per each): $0.00
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
IV:
Dosimetric dose: Administer over 60 seconds.
Therapeutic dose: Verify patency if the primary infusion line by infusing NS 250 mL at 200 mL/hour. Insert a venting unit into the 50 mL glass vial containing the therapeutic dose. Assemble a second infusion line using a 19-gauge x 5-inch aspirating needle, 24 inch M-M arterial pressure tubing and a primary set specific connector; clamp the second infusion line and connect it to the primary intravenous line via the primary set specific connector. Release the clamp to flush the second infusion line, then re-clamp. Insert the needle of the second infusion line into the 50 mL glass vial containing the therapeutic dose, ensuring the needle reaches the bottom of the glass vial without touching the vial sides. Clamp the primary infusion line just above the second infusion line and remove the clamp from the secondary infusion line. Administer the therapeutic dose over 30 minutes (at 100 mL/hour). Clamp the secondary infusion line when the first air bubbles form. Remove the clamp from the primary infusion line to flush residual therapeutic dose within the line with at least NS 50 mL. Remove the clamp from the secondary infusion line and flush residual drug in the secondary line into the 50 mL glass vial.
IV: Radiopharmaceutical; use appropriate precautions for handling and disposal. When handling and administering, follow appropriate safety measures to minimize radiation exposure during administration; use waterproof gloves and effective shielding, including syringe shields.
Dosimetric dose: Administer over 60 seconds.
Therapeutic dose: Verify patency of the primary infusion line by infusing 250 mL of NS at 200 mL/hour. Insert a venting unit into the 50-mL glass vial containing the therapeutic dose. Assemble a second infusion line using a 19-gauge x 5-inch aspirating needle, 24-inch M-M arterial pressure tubing, and a primary set specific connector; clamp the second infusion line and connect it to the primary intravenous line via the primary set specific connector. Release the clamp to flush the second infusion line, then re-clamp. Insert the needle of the second infusion line into the 50-mL glass vial containing the therapeutic dose, ensuring the needle reaches the bottom of the glass vial without touching the vial sides. Clamp the primary infusion line just above the second infusion line and remove the clamp from the secondary infusion line. Administer the therapeutic dose over 60 minutes (at 50 mL/hour) for pediatric patients ≥12 years and over 30 minutes (at 100 mL/hour) is used in adults. Clamp the secondary infusion line when the first air bubbles form. Remove the clamp from the primary infusion line to flush residual therapeutic dose within the line with at least 50 mL of NS. Remove the clamp from the secondary infusion line and flush residual drug in the secondary line into the 50-mL glass vial.
Pheochromocytoma or paraganglioma, unresectable, locally advanced or metastatic: Treatment of iobenguane scan positive, unresectable, locally advanced or metastatic pheochromocytoma or paraganglioma in adult and pediatric patients ≥12 years who require systemic anticancer therapy.
Azedra may be confused with Arzerra
Iobenguane I 131 may be confused with iobenguane I 123, iodinated I 131 albumin, sodium iodide I 131
Radiopharmaceutical: Use appropriate precaution for handling, disposal, and minimizing exposure to patients and health care personnel. Use under supervision of experienced personnel. Should be stored in original lead container or adequate radiation shield.
None known.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
5-Aminosalicylic Acid Derivatives: May increase myelosuppressive effects of Myelosuppressive Agents. Risk C: Monitor
Abrocitinib: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
Alpha-/Beta-Agonists (Indirect-Acting): May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Risk X: Avoid
Alpha1-Agonists: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Risk X: Avoid
Amphetamines: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Risk X: Avoid
Antithymocyte Globulin (Equine): Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Antithymocyte Globulin (Equine). Specifically, these effects may be unmasked if the dose of immunosuppressive therapy is reduced. Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Antithymocyte Globulin (Equine). Specifically, infections may occur with greater severity and/or atypical presentations. Risk C: Monitor
Antithyroid Agents: Myelosuppressive Agents may increase neutropenic effects of Antithyroid Agents. Risk C: Monitor
Baricitinib: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Baricitinib. Risk X: Avoid
BCG (Intravesical): Myelosuppressive Agents may decrease therapeutic effects of BCG (Intravesical). Myelosuppressive Agents may increase adverse/toxic effects of BCG (Intravesical). Risk X: Avoid
BCG Products: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of BCG Products. Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of BCG Products. Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Brincidofovir: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Brincidofovir. Risk C: Monitor
Brivudine: May increase adverse/toxic effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
BuPROPion: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer bupropion until at least 7 days after each iobenguane dose. Risk X: Avoid
Chikungunya Vaccine (Live): Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Chikungunya Vaccine (Live). Specifically, the risk of vaccine-associated infection may be increased. Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Chikungunya Vaccine (Live). Risk X: Avoid
Chloramphenicol (Ophthalmic): May increase adverse/toxic effects of Myelosuppressive Agents. Risk C: Monitor
Chloramphenicol (Systemic): Myelosuppressive Agents may increase myelosuppressive effects of Chloramphenicol (Systemic). Risk X: Avoid
Cladribine: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Cladribine. Risk X: Avoid
Cladribine: May increase myelosuppressive effects of Myelosuppressive Agents. Risk X: Avoid
CloZAPine: Myelosuppressive Agents may increase adverse/toxic effects of CloZAPine. Specifically, the risk for neutropenia may be increased. Risk C: Monitor
CNS Stimulants: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Risk X: Avoid
Cocaine (Topical): May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer cocaine until at least 7 days after each iobenguane dose. Risk X: Avoid
Coccidioides immitis Skin Test: Coadministration of Immunosuppressants (Miscellaneous Oncologic Agents) and Coccidioides immitis Skin Test may alter diagnostic results. Management: Consider discontinuing these oncologic agents several weeks prior to coccidioides immitis skin antigen testing to increase the likelihood of accurate diagnostic results. Risk D: Consider Therapy Modification
COVID-19 Vaccine (Inactivated Virus): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of COVID-19 Vaccine (Inactivated Virus). Risk C: Monitor
COVID-19 Vaccine (mRNA): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of COVID-19 Vaccine (mRNA). Management: Give a 3-dose primary series for all patients aged 6 months and older taking immunosuppressive medications or therapies. Booster doses are recommended for certain age groups. See CDC guidance for details. Risk D: Consider Therapy Modification
COVID-19 Vaccine (Subunit): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of COVID-19 Vaccine (Subunit). Risk C: Monitor
Deferiprone: Myelosuppressive Agents may increase neutropenic effects of Deferiprone. Management: Avoid the concomitant use of deferiprone and myelosuppressive agents whenever possible. If this combination cannot be avoided, monitor the absolute neutrophil count more closely. Risk D: Consider Therapy Modification
Dengue Tetravalent Vaccine (Live): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Dengue Tetravalent Vaccine (Live). Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Dengue Tetravalent Vaccine (Live). Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Denosumab: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Management: Consider the risk of serious infections versus the potential benefits of coadministration of denosumab and immunosuppressants. If combined, monitor patients for signs/symptoms of serious infections. Risk D: Consider Therapy Modification
Deucravacitinib: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
Etrasimod: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
Fexinidazole: Myelosuppressive Agents may increase myelosuppressive effects of Fexinidazole. Risk X: Avoid
Filgotinib: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
Guanethidine: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer guanethidine until at least 7 days after each iobenguane dose. Risk X: Avoid
Inebilizumab: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Inebilizumab. Risk C: Monitor
Influenza Virus Vaccines: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Influenza Virus Vaccines. Management: Administer influenza vaccines at least 2 weeks prior to initiating immunosuppressants if possible. If vaccination occurs less than 2 weeks prior to or during therapy, revaccinate at least 3 months after therapy discontinued if immune competence restored. Risk D: Consider Therapy Modification
Labetalol: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer labetalol until at least 7 days after each iobenguane dose. Risk X: Avoid
Leflunomide: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Leflunomide. Management: Increase the frequency of chronic monitoring of platelet, white blood cell count, and hemoglobin or hematocrit to monthly, instead of every 6 to 8 weeks, if leflunomide is coadministered with immunosuppressive agents. Risk D: Consider Therapy Modification
Maprotiline: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer maprotiline until at least 7 days after each iobenguane dose. Risk X: Avoid
Methyldopa: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer methyldopa until at least 7 days after each iobenguane dose. Risk X: Avoid
MetyroSINE: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer metyrosine until at least 7 days after each iobenguane dose. Risk X: Avoid
Monoamine Oxidase Inhibitors: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Risk X: Avoid
Mumps- Rubella- or Varicella-Containing Live Vaccines: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Mumps- Rubella- or Varicella-Containing Live Vaccines. Mumps- Rubella- or Varicella-Containing Live Vaccines may increase adverse/toxic effects of Immunosuppressants (Miscellaneous Oncologic Agents). Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Nadofaragene Firadenovec: Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Nadofaragene Firadenovec. Specifically, the risk of disseminated adenovirus infection may be increased. Risk X: Avoid
Natalizumab: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Natalizumab. Risk X: Avoid
Ocrelizumab: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Ocrelizumab. Risk C: Monitor
Ofatumumab: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Ofatumumab. Risk C: Monitor
Olaparib: Myelosuppressive Agents may increase myelosuppressive effects of Olaparib. Risk C: Monitor
Pidotimod: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Pidotimod. Risk C: Monitor
Pimecrolimus: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
Pneumococcal Vaccines: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Pneumococcal Vaccines. Risk C: Monitor
Poliovirus Vaccine (Live/Trivalent/Oral): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Poliovirus Vaccine (Live/Trivalent/Oral). Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Poliovirus Vaccine (Live/Trivalent/Oral). Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Polymethylmethacrylate: Immunosuppressants (Miscellaneous Oncologic Agents) may increase hypersensitivity effects of Polymethylmethacrylate. Management: Use caution when considering use of bovine collagen-containing implants such as the polymethylmethacrylate-based Bellafill brand implant in patients who are receiving immunosuppressants. Consider use of additional skin tests prior to administration. Risk D: Consider Therapy Modification
Promazine: May increase myelosuppressive effects of Myelosuppressive Agents. Risk C: Monitor
Rabies Vaccine: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Rabies Vaccine. Management: Complete rabies vaccination at least 2 weeks before initiation of immunosuppressant therapy if possible. If combined, check for rabies antibody titers, and if vaccination is for post exposure prophylaxis, administer a 5th dose of the vaccine. Risk D: Consider Therapy Modification
Reserpine: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer reserpine until at least 7 days after each iobenguane dose. Risk X: Avoid
Ritlecitinib: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Ritlecitinib. Risk X: Avoid
Ropeginterferon Alfa-2b: Myelosuppressive Agents may increase myelosuppressive effects of Ropeginterferon Alfa-2b. Management: Avoid coadministration of ropeginterferon alfa-2b and other myelosuppressive agents. If this combination cannot be avoided, monitor patients for excessive myelosuppressive effects. Risk D: Consider Therapy Modification
Ruxolitinib (Topical): Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Ruxolitinib (Topical). Risk X: Avoid
Selective Norepinephrine Reuptake Inhibitors: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Risk X: Avoid
Serotonin/Norepinephrine Reuptake Inhibitor: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Risk X: Avoid
Sipuleucel-T: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Sipuleucel-T. Management: Consider reducing the dose or discontinuing the use of immunosuppressants prior to initiating sipuleucel-T therapy. Risk D: Consider Therapy Modification
Sodium Perchlorate: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Risk C: Monitor
Sphingosine 1-Phosphate (S1P) Receptor Modulators: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk C: Monitor
St John's Wort: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer St John's wort until at least 7 days after each iobenguane dose. Risk X: Avoid
Tacrolimus (Topical): Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Tacrolimus (Topical). Risk X: Avoid
Talimogene Laherparepvec: Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Talimogene Laherparepvec. Specifically, the risk of infection from the live, attenuated herpes simplex virus contained in talimogene laherparepvec may be increased. Risk X: Avoid
Tapentadol: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer tapentadol until at least 7 days after each iobenguane dose. Risk X: Avoid
Tertomotide: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Tertomotide. Risk X: Avoid
Tofacitinib: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Tofacitinib. Risk X: Avoid
TraMADol: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer tramadol until at least 7 days after each iobenguane dose. Risk X: Avoid
Tricyclic Antidepressants: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Risk X: Avoid
Typhoid Vaccine: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Typhoid Vaccine. Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Typhoid Vaccine. Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Ublituximab: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Ublituximab. Risk C: Monitor
Upadacitinib: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Upadacitinib. Risk X: Avoid
Vaccines (Live): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Vaccines (Live). Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Vaccines (Live). Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Vaccines (Non-Live/Inactivated/Non-Replicating): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Vaccines (Non-Live/Inactivated/Non-Replicating). Management: Give non-live/inactivated/non-replicating vaccines at least 2 weeks prior to initiation of immunosuppressants when possible. Patients vaccinated less than 14 days before or during therapy should be revaccinated at least 3 months after therapy is complete. Risk D: Consider Therapy Modification
Yellow Fever Vaccine: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Yellow Fever Vaccine. Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Yellow Fever Vaccine. Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Yohimbine: May decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer yohimbine until at least 7 days after each iobenguane dose. Risk X: Avoid
Zoster Vaccine (Live/Attenuated): Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Zoster Vaccine (Live/Attenuated). Specifically, the risk of vaccine-associated infection may be increased. Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Zoster Vaccine (Live/Attenuated). Risk X: Avoid
Pregnancy status should be evaluated prior to therapy. Females of reproductive potential should use effective contraception during treatment and for 7 months after the last iobenguane I 131 dose. Males with female partners of reproductive potential should use effective contraception during treatment and for 4 months after the last iobenguane I 131 dose. Temporary or permanent infertility may occur in females and males due to radiation exposure that occurs with therapy.
Based on the mechanism of action, iobenguane I 131 would be expected to cause fetal harm.
It is not known if iobenguane I 131 is present in breast milk.
Due to the potential for serious adverse reactions in the breastfed infant, breastfeeding is not recommended by the manufacturer during therapy or for 80 days after the last iobenguane I 131 dose.
Monitor blood cell counts (weekly for up to 12 weeks or until return to baseline or normal range); renal function (during and after treatment; more frequently in patients with baseline mild or moderate renal impairment); thyroid-stimulating hormone (TSH) levels (prior to treatment initiation and then annually thereafter or as clinically indicated; some resources recommend monitoring TSH every 6 months for life [Hamnvik 2011]); pregnancy test (prior to treatment in females of reproductive potential). Monitor blood pressure (frequently during the first 24 hours after each therapeutic dose). Evaluate for signs/symptoms of hypothyroidism and pneumonitis; monitor for secondary malignancies.
Radiation absorbed dose estimates by target organ following an IV iobenguane I 131 dose of ~5 mCi (SI: ~185 MBq): Refer to product labeling.
Iobenguane I 131 is an I 131 labeled radiopharmaceutical which is similar in structure to the neurotransmitter norepinephrine and subject to the same norepinephrine uptake and accumulation pathways. Iobenguane is taken up by the norepinephrine transporter in adrenergic nerve terminals and accumulates in innervated adrenergic tissues (eg, heart, lungs, adrenal medulla, salivary glands, liver, and spleen, as well as tumors of neural crest origin). Pheochromocytoma and paraganglioma are neural crest origin tumors which express high norepinephrine transporter levels on cell surfaces. Iobenguane I 131 is taken up and accumulates within pheochromocytoma and paraganglioma cells; radiation from radioactive decay of I 131 results in cell death and tumor necrosis.
Distribution: Vd: 2,893 ± 592 mL/kg
Protein binding: 61% to 63% (nonradioactive form); to human plasma proteins
Metabolism: Does not undergo hepatic metabolism
Half-life elimination: Mean terminal blood half-life: 35 ± 14 hours
Time to peak: Generally occurs at the end of infusion
Excretion: Urine (primarily)
Altered kidney function: Due to delayed elimination, the radiation dose may be increased in patients with renal impairment.
