Iobenguane I 131 Disease Interactions

Eleven percent of patients who received a therapeutic dose of iobenguane I-131 experienced a worsening of preexisting hypertension defined as an increase in systolic blood pressure to =160 mmHg with an increase of 20 mmHg or an increase in diastolic blood pressure to = 100 mmHg with an increase of 10 mmHg. All changes in blood pressure occurred within the first 24 hours post infusion. Blood pressure should be frequently monitored during the first 24 hours after each therapeutic dose of iobenguane I-131.

Renal failure or acute kidney injury and a demonstrated clinically significant decrease in glomerular filtration rate (GFR) has been reported in some patients receiving iobenguane I-131. Monitor renal function during and after treatment with iobenguane I-131. Patients with baseline renal impairment may be at greater risk of toxicity, and their radiation dose may be increased due to the delayed elimination of the drug. Adjust the therapeutic dose based on radiation exposure estimates from the dosimetry assessment. Perform more frequent assessments of renal function in patients with mild or moderate impairment. Iobenguane I-131 has not been studied in patients with severe renal impairment (creatinine clearance <30 mL/min), or end-stage renal disease.

Hypothyroidism was reported in patients who received a therapeutic dose of iobenguane I-131. Caution and close monitoring is advised in patients with history of hypothyroidism. Initiate thyroid- blocking medications starting at least 1 day before and continuing for 10 days after each iobenguane I-131 dose to reduce the risk of hypothyroidism or thyroid neoplasia. Evaluate for clinical evidence of hypothyroidism and measure thyroid-stimulating hormone (TSH) levels prior to initiating treatment with iobenguane I-131 and annually thereafter.