Fluorodopa F18 (Page 2 of 3)

3 DOSAGE FORMS AND STRENGTHS

Injection: clear, colorless solution containing 37 MBq/mL to 1,480 MBq/mL (1 mCi/mL to 40 mCi/mL) of Fluorodopa F 18 Injection, at calibration time in a multiple-dose glass vial.

4 CONTRAINDICATIONS

None

5 WARNINGS AND PRECAUTIONS

5.1 Radiation Risks

Fluorodopa F 18 Injection use contributes to a patient’s overall long-term radiation exposure, which is associated with an increased risk of cancer. Use the smallest dose necessary for imaging and ensure safe handling to protect the patient and health care worker [see Dosage and Administration (2.1, 2.2)].

6 ADVERSE REACTIONS

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. No adverse reactions have been reported for Fluorodopa F 18 Injection based on an open-label clinical trial in 68 patients [see Clinical Studies ( 14)] and additional clinical experience in 53 patients.

6.2 Postmarketing Experience

The following adverse reactions have been identified during post approval of use of Fluorodopa F 18 Injection outside of the United States. Because these 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.

General Disorders and Administration Site Conditions: Pain

7 DRUG INTERACTIONS

Aromatic L-amino acid decarboxylase (AADC) inhibitors
Prior to Fluorodopa F 18 Injection administration, use of AADC inhibitors (e.g. carbidopa, benserazide etc.) may increase Fluorodopa F 18 bioavailability to the brain by inhibiting peripheral decarboxylase activity and restricting peripheral Fluorodopa F 18 metabolism [see Dosage and Administration (2.3)].

Dopamine agonists, dopamine reuptake inhibitors, dopamine releasing agents (DRAs), peripheral catechol-O-methyltransferase (COMT) inhibitors, and monoamine oxidase (MAO) inhibitors
Therapy for Parkinson’s syndromes includes dopamine agonists, dopamine reuptake inhibitors, dopamine releasing agents (DRAs) such as psychostimulants of the amphetamine class, peripheral catechol-O-methyltransferase (COMT) inhibitors, and monoamine oxidase (MAO) inhibitors. Whether discontinuation of these drugs prior to Fluorodopa F 18 administration may minimize the interference with a Fluorodopa F 18 image is not fully known; however, if use of these drugs can be safely suspended, discontinue use 12 hours before administration of Fluorodopa F18 Injection [see Dosage and Administration (2.3)].

8 USE IN SPECIFIC POPULATIONS

8.1 Pregnancy

Risk Summary
There are no available data on Fluorodopa F 18 Injection use in pregnant women. Additionally, animal reproductive and developmental toxicity studies have not been conducted with Fluorodopa F 18 Injection. However, all radiopharmaceuticals, including Fluorodopa F 18 Injection, have a potential to cause fetal harm depending on the stage of fetal development, and the magnitude of the radiation dose. If considering Fluorodopa F 18 Injection administration to a pregnant woman, inform the patient about the potential for adverse pregnancy outcomes based on the radiation dose from the drug and the gestational timing of exposure.

The estimated background risk of major birth defects and miscarriage for the indicated population 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 risks of major birth defects and miscarriage in clinically recognized pregnancies are 2 to 4% and 15 to 20%, respectively, regardless of drug exposure.

8.2 Lactation

Risk Summary
No data are available regarding the presence of Fluorodopa F 18 Injection in human milk, the effects of the drug on the breastfed child, or the effects of the drug on milk production. Exposure of Fluorodopa F 18 Injection to a breast fed infant can be minimized by temporary discontinuation of breastfeeding [see Clinical Considerations]. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Fluorodopa F 18 Injection and any potential adverse effects on the breastfed child from Fluorodopa F 18 Injection or from the underlying maternal condition.

The body of scientific information related to radioactivity decay, drug tissue distribution and drug elimination shows that less than 0.01% of the radioactivity administered remains in the body after 24 hours.

Clinical ConsiderationsTo decrease radiation exposure to a nursing infant, advise a lactating woman to pump and discard breastmilk for at least 24 hours (12 half-lives) after administration of Fluorodopa F 18 Injection.

8.4 Pediatric Use

The safety and effectiveness of Fluorodopa F 18 Injection for visualization of dopaminergic neurons in the striatum has not been established in pediatric patients.

11 DESCRIPTION

11.1 Chemical Characteristics

Fluorodopa F 18 Injection is a radioactive diagnostic agent used in PET imaging. The active ingredient 6-[18 F] Fluoro-L-3, 4-dihydroxyphenylalanine has the molecular formula of C9 H10 FNO4 with a molecular weight of 214.18, and has the following chemical structure:

FDOPA Structure

Fluorodopa F 18 Injection is a sterile, pyrogen-free, clear, colorless solution. Each mL contains between 37 MBq/mL to 1,480 MBq/mL (1 mCi/mL to 40 mCi/mL) of no-carrier added Fluorodopa F 18 (6-[18 F] Fluoro-L-3, 4-dihydroxyphenylalanine) at the end of synthesis (EOS). There is 40.88 mg Na-EDTA, 140 mg ascorbic acid, and 663 mg ethanol in 28 mL ±1 mL sodium phosphate buffer. The pH of the solution is between 3 and 5.

11.2 Physical Characteristics

Fluorine F 18 is a cyclotron produced radionuclide that decays by positron emission to Oxygen O 18 (stable) and has a physical half-life of 109.7 minutes. The principal photons useful for imaging are the dual 511 keV gamma photons, which are produced and emitted simultaneously in opposite direction following positron-electron annihilation (Table 2).

Table 2. Principal Radiation Emission Data for Fluoride F 18
Radiation/Emission % Per Disintegration Mean Energy
Positron(+) 96.73 249.8 keV
Gamma(±)* 193.46 511.0 keV

* Produced by positron annihilation

11.3 External Radiation

The point source air-kerma coefficient for F 18 is 3.75 × 10-17 Gy m2 / (Bq s). The half-value layer (HVL) for the 511 keV photons is 5 mm lead (Pb). The range of attenuation coefficients for this radionuclide as a function of lead shield thickness is shown in Table 3. For example, the interposition of a 9 mm thickness of Pb, with a coefficient of attenuation of 0.25, will decrease the external radiation by 75%.

Table 3. Radiation Attenuation of 511 keV Photons by lead (Pb) shielding
Shield thickness (Pb) mm Coefficient of Attenuation
0 0.00
5 0.50
9 0.25
15 0.10
29 0.01
39 0.001
52 0.0001

For use in correcting for physical decay of this radionuclide, the fractions remaining at selected intervals after calibration are shown in Table 4.

Table 4. Physical Decay Chart for Fluorine F 18
Time Since Calibration Fraction Remaining
0* 1.000
15 min 0.909
30 min 0.826
60 min 0.683
110 min 0.500
220 min 0.250
440 min 0.060
12 hours 0.011
24 hours 0.0001

* Calibration time

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