Ioflupane i-123

Ioflupane I 123 binds to the dopamine transporter [see Clinical Pharmacology (12.1) ] . Drugs that bind to the dopamine transporter with high affinity have the potential to impact DATSCAN image interpretation. These potentially interfering drugs include: amoxapine, amphetamine, armodafinil, benztropine, bupropion, buspirone, cocaine, mazindol, methamphetamine, methylphenidate, modafinil, norephedrine, phentermine, selegiline, and sertraline. Selective serotonin reuptake inhibitors (paroxetine and citalopram) may increase or decrease ioflupane binding to the dopamine transporter.

In patients taking venlafaxine or desvenlafaxine prior to DATSCAN administration, there have been cases of altered DATSCAN uptake that impacted image interpretation. The mechanism of interference of these drugs with DATSCAN imaging is not known. Whether discontinuation of any of the above drugs prior to DATSCAN administration may minimize the impact on image interpretation is unknown; however, if use of these drugs can be safely suspended, consider discontinuing for at least 5 biological half-lives before administration of DATSCAN [see Dosage and Administration (2.3) ]. The impact of dopamine agonists and antagonists upon DATSCAN imaging results has not been established.

Amoxapine, amphetamine, armodafinil, benztropine, bupropion, buspirone, cocaine, mazindol, methamphetamine, methylphenidate, modafinil norephedrine, phentermine, selegiline, sertraline, citalopram, paroxetine, venlafaxine, and desvenlafaxine may impact DATSCAN image interpretation. Consider discontinuing drugs that may interfere with DATSCAN images for at least 5 biological half-lives before administration of DATSCAN if use of these drugs can be safely suspended. ( 2.3 , 7 )

8.1 Pregnancy Risk Summary Radioactive iodine products cross the placenta and can permanently impair fetal thyroid function. Administration of an appropriate thyroid blocking agent is recommended before use of DATSCAN in a pregnant woman to protect the woman and fetus from accumulation of iodine-123 [see Dosage and Administration (2.3) ] . There are no available data on DATSCAN use in pregnant women to evaluate for a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. Animal reproduction studies have not been conducted with ioflupane I 123.

All radiopharmaceuticals have the potential to cause fetal harm depending on the fetal stage of development and the magnitude of the radiation dose. Administration of DATSCAN at a dose of 185 MBq (5 mCi) results in an absorbed radiation dose to the uterus of 0.3 rad (3.0 mGy). Radiation doses greater than 15 rad (150 mGy) have been associated with congenital anomalies but doses under 5 rad (50 mGy) generally have not. Advise pregnant women of the potential risks of fetal exposure to radiation doses with administration of DATSCAN. The estimated background risk of major birth defects and miscarriage for the indicated population(s) is unknown.

All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.