DATSCAN Solution for injection Ref.[10327] Active ingredients: Ioflupane ¹²³I

5.1 Hypersensitivity Reactions

Hypersensitivity reactions have been reported following DaTscan administration [see Adverse Reactions (6.2)]. The reactions have generally consisted of skin erythema and pruritis and have either resolved spontaneously or following the administration of corticosteroids and anti-histamines. Prior to administration, question the patient for a history of prior reactions to DaTscan. If the patient is known or strongly suspected of having had a hypersensitivity reaction to DaTscan, the decision to administer DaTscan should be based upon an assessment of the expected benefits compared to the potential hypersensitivity risks. Have anaphylactic and hypersensitivity treatment measures available prior to DaTscan administration and, following administration, observe patients for symptoms or signs of a hypersensitivity reaction.

5.2 Thyroid Accumulation

The DaTscan injection may contain up to 6% of free iodide (iodine 123). To decrease thyroid accumulation of iodine 123, block the thyroid gland before administration of DaTscan [see Dosage and Administration (2.2)]. Avoid the use of Potassium Iodide Oral Solution or Lugol’s Solution in patients who are sensitive to such products. Failure to block thyroid uptake of iodine 123 may result in an increased long term risk for thyroid neoplasia.

The data from clinical studies reflect exposure to DaTscan in 942 subjects with a mean age of 66 years (range 25 to 90 years). Among these subjects, 42% were women and 99% Caucasian. Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of DaTscan cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In clinical trials, no serious adverse reactions were reported. Other adverse reactions occurred at a rate of 1% or less and the reported events consisted of headache, nausea, vertigo, dry mouth or dizziness. These reactions were of mild to moderate severity.

Because postmarketing reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. In the postmarketing experience, hypersensitivity reactions have been reported. The reactions generally related to rash and pruritis within minutes of DaTscan administration. The reactions either resolved spontaneously or following the administration of corticosteroids and antihistamines. Injection site pain has also been reported.

The ioflupane within DaTscan binds to the dopamine transporter. Drugs that bind to the dopamine transporter with high affinity may interfere with the image obtained following DaTscan administration. These potentially interfering drugs consist of: amoxapine, amphetamine, benztropine, bupropion, buspirone, cocaine, mazindol, methamphetamine, methylphenidate, norephedrine, phentermine, phenylpropanolamine, selegiline, and sertraline. Selective serotonin reuptake inhibitors (paroxetine and citalopram) may increase or decrease ioflupane binding to the dopamine transporter. Whether discontinuation of these drugs prior to DaTscan administration may minimize the interference with a DaTscan image is unknown.

The impact of dopamine agonists and antagonists upon DaTscan imaging results has not been established.

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 I 123 [see Dosage and Administration (2.2)].

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.

Risk Summary

Iodide 123 (I 123), the radionuclide in DaTscan, is present in human milk. There is no information on the effects on the breastfed infant or on milk production. Advise a lactating woman to interrupt breastfeeding and pump and discard breastmilk for at least 6 days (>10 physical half-lives) after DaTscan administration in order to minimize radiation exposure to a breastfed infant.

DaTscan is not indicated for use in children. The safety and efficacy of DaTscan have not been established in pediatric patients.

In the two principal clinical studies, 45% of the subjects were aged 65 and over. There were no differences in response compared to younger subjects that would require a dose adjustment. Other reported clinical experience has not identified differences in responses between the elderly and younger patients.

8.6 Renal and Hepatic Impairment

The effect of renal or hepatic impairment upon DaTscan imaging has not been established. DaTscan is excreted by the kidney and patients with severe renal impairment may have increased radiation exposure and altered DaTscan images.