technetium Tc 99m exametazime (Rx)

Frequency Not Defined

Hypersensitivity, including anaphylaxis

Postmarketing Reports

Cardiovascular: Transient blood pressure increase

Skin and subcutaneous tissue disorders: Rash, generalized erythema, urticaria, angioedema, pruritus

General disorders and administration site conditions: Facial edema, fever, asthenic conditions (eg, malaise, fatigue)

Nervous system disorders: Headache, dizziness, paresthesia

Vascular disorders: Flushing

Gastrointestinal disorders: Nausea, vomiting

Contraindications

None

Cautions

Hypersensitivity reactions, including serious signs and symptoms of anaphylaxis, following administration of Tc 99m labeled leukocytes prepared using Tc 99m exametazime have been reported; monitor for hypersensitivity reactions and always have cardiopulmonary resuscitation equipment and personnel available

Image interpretation may be affected by presence of other pathophysiological processes within and outside of the abdominal cavity (eg, tumor, infarction, trauma, and other inflammatory conditions)

Technetium Tc 99m contributes to a patient’s overall long-term cumulative radiation exposure; long-term cumulative radiation exposure is associated with an increased risk of cancer; ensure safe handling and preparation reconstitution procedures to protect patients and health care workers from unintentional radiation exposure; encourage patients to drink fluids and void as frequently as possible after administration

Pregnancy

Limited available data with technetium Tc 99m exametazime use in pregnant women are insufficient to inform a drug associated risk for major birth defects and miscarriage

Animal reproduction studies with technetium Tc 99m exametazime have not been conducted

Inform patients who are pregnant or may become pregnant about the potential for adverse pregnancy outcomes based on the radiation dose from technetium Tc 99m exametazime and the gestational timing of exposure

Limited data describes technetium Tc 99m exametazime crossing the placental barrier and visualization of radioactivity in the fetal liver; no adverse fetal effects or radiation-related risks have been identified for diagnostic procedures involving less than 50 mGy, which represents less than 10 mGy fetal doses

Lactation

Unknown if distributed in human breast milk

To decrease radiation exposure to the breastfed infant, advise a lactating woman to pump and discard breast milk after administration of technetium Tc 99m exametazime-labeled leukocytes for 12-24 hours, where the duration corresponds to the typical range of administered activity, 259-925 MBq (7-25 mCi)

Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for the drug, and any potential adverse effects on the breastfed infant from the drug or from the underlying maternal condition

Pregnancy Categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

Mechanism of Action

The addition of technetium Tc 99m pertechnetate to exametazime in the presence of stannous reductant, a lipophilic technetium Tc 99m complex is formed; this lipophilic complex is the active moiety; lipophilic technetium Tc 99m exametazime complex is taken up and retained in leukocytes

Distribution

<1 hr postinjection: Radioactivity is seen in lungs, liver, gall bladder, spleen, blood pool, bone marrow, kidneys, and bladder

First 1-6 hr postinjection: Tc 99m is visualized in the bowel

24 hr postinjection: Substantial colonic activity is seen; normal areas visualized in earlier scans are still visible

Elimination

Half-life: Physical: ~6 hr

Excretion: Urine and kidneys (~40%); Feces (~50%)

Technetium Tc 99 Exametazime Preparation

Contents of vial are sterile and pyrogen free; vial contains no bacteriostatic preservative; follow the directions carefully and adhere to strict aseptic procedures during preparation of the radiopharmaceutical; see full prescribing information for detailed instructions

0.37 – 2 GBq (10 - 54 mCi) technetium Tc99m may be added to the vial

Before reconstitution the technetium Tc99m generator eluate may be adjusted to the correct radioactive concentration to a volume of 5 mL by dilution with preservative-free, nonbacteriostatic 0.9% sodium chloride for injection

Use only eluate from a technetium Tc99m generator which was previously eluted within 24 hr; generator eluate >2 hr old should not be used; for the highest radiochemical purity reconstitute with freshly eluted technetium Tc99m generator eluate

Radiochemical purity testing must be performed prior to patient administration; radiochemical purity >80% is necessary for product acceptance

Do not use the final radiopharmaceutical preparation more than 30 minutes after the time of reconstitution; discard any unused material

Ceretec preparation

• When reconstituting a vial of Ceretec with 31-54 mCi, generator eluate more than 30 minutes old should not be used
• Do not use methylene blue stabilizer for leukocyte labeling procedure

Administration for Leukocyte Labeled Scintigraphy

Use strict aseptic procedures throughout preparation and handling

Visually inspect reconstituted technetium Tc 99m exametazime solution for particulate matter and discoloration prior to radiolabeling of white blood cells

Do not use the reconstituted solution if there is evidence of particulate matter or discoloration

Follow the directions of drug preparation carefully to ensure efficient leukocytes labeling

Measure patient dose with a suitable radioactivity calibration system immediately prior to administration

Instruct patients to hydrate, after administration of technetium Tc 99m exametazime labeled white blood cells and void frequently to minimize radiation dose to the kidneys and bladder

Storage for All Formulations

Unopened kit

• Store in original packaging at controlled room temperature 15-25°C (59-77°F)

Reconstituted product

• Store reconstituted injection at 20-25°C (68-77°F) using appropriate radiation shielding

• Expiration of radiolabeled product

  • Ceretec with methylene blue stabilizer: 4 hr post-preparation
  • Ceretec without methylene blue stabilizer: 30 minutes post-preparation Drax Exemestane: 4 hr post-preparation