Ioflupane i-123

DATSCAN is indicated as an adjunct to other diagnostic evaluations for striatal dopamine transporter visualization using single photon emission computed tomography (SPECT) brain imaging in adult patients with: suspected Parkinsonian syndromes (PS) or suspected dementia with Lewy bodies (DLB). DATSCAN is a radioactive diagnostic agent indicated as an adjunct to other diagnostic evaluations for striatal dopamine transporter visualization using single photon emission computed tomography (SPECT) brain imaging in adult patients with: suspected Parkinsonian syndromes (PS) or suspected dementia with Lewy bodies (DLB).

The active drug substance in DATSCAN is N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-[ 123 I]iodophenyl)nortropane or ioflupane I 123. In vitro, ioflupane binds reversibly to the human dopamine transporter (DaT) (Ki = 0.62 nM, IC 50 = 0.71 nM). Autoradiography of post-mortem human brain slices exposed to radiolabeled ioflupane shows concentration of the radiolabel in striatum (caudate nucleus and putamen). The specificity of the binding of ioflupane I 125 to dopamine transporter was demonstrated by competition studies with the DaT inhibitor GBR 12909 (a dopamine reuptake inhibitor), the serotonin reuptake inhibitor citalopram, and the norepinephrine reuptake inhibitor desipramine in post-mortem human brain slices exposed to radiolabeled ioflupane. Citalopram reduced binding in the neocortex and thalamus with only minor effects in the striatum.

The recommended dose of DATSCAN in adult patients is 111 MBq to 185 MBq (3 mCi to 5 mCi) administered intravenously over at least 20 seconds. Administer a thyroid blocking agent at least one hour before the dose of DATSCAN. Begin SPECT imaging between 3 hours and 6 hours post injection. See full prescribing information for image interpretation and radiation dosimetry.

DATSCAN is contraindicated in patients with known serious hypersensitivity to ioflupane I 123. Known serious hypersensitivity to ioflupane I 123

Hypersensitivity Reactions: Hypersensitivity reactions including dyspnea, edema, rash, erythema, and pruritus have been reported. Have treatment measures available prior to DATSCAN administration. Thyroid Accumulation of Iodine-123: Thyroid uptake of iodine-123 may result in an increased long-term risk for thyroid neoplasia. Radiation Risk: Ensure safe handling to minimize radiation exposure to the patient and healthcare providers. Advise patients to hydrate before and after administration and to void frequently after administration.

The following clinically significant adverse reaction is described elsewhere in the labeling: Hypersensitivity Reactions The following adverse reactions were reported at ≤1%: headache, nausea, vertigo, dry mouth and dizziness.

Ioflupane I 123 binds to the dopamine transporter. 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.

Store DATSCAN at 20° to 25°C (68° to 77°F). Store DATSCAN within the original lead container or equivalent radiation shielding.