Professional Information
Technetium Tc 99m Apcitide (Systemic)
VA CLASSIFICATION
Primary: DX201
Commonly used brand name(s): AcuTect.
Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).
Category:
Diagnostic aid, radioactive (thrombosis)—
Indications
Accepted
Thrombosis, deep venous (diagnosis)—Technetium Tc 99m apcitide is indicated for scintigraphic imaging of acute venous thrombosis in the lower extremities in patients with signs and symptoms of acute blood clots {01}.
Physical Properties
Nuclear Data {01}
| Radionuclide (half-life) |
Mode of decay |
Principal photon emissions (keV) |
Mean number of emissions/ disintegration |
|---|---|---|---|
| Tc 99m (6 hr) |
Isomeric transition to Tc 99 |
Gamma (18) Gamma (140.5) |
0.062 0.891 |
Pharmacology/Pharmacokinetics
Mechanism of action/Effect:
The mechanism of action of technetium Tc 99m apcitide is based on the binding of the small-molecule synthetic peptide, apcitide, to the GPIIb/IIIa receptors on the surface of activated platelets, which are a major component in active thrombus formation {01}. Since the peptide is combined with a molecule of technetium Tc 99m, the localization of radioactivity may be recorded by gamma-ray detection cameras {01}.
Distribution:
Volume of distribution at steady state (Vss)—0.16 ± 0.06 L per kg of body weight (L/kg) following intravenous administration in adult patients (age range, 27 to 81 years) of 65 to 90 mcg of bibacitide containing 514.3 to 784.4 megabecquerels (13.9 to 21.2 millicuries) of technetium Tc 99m {01}.
Protein binding:
High (75.8 ± 13.4% [mean ± SD]) {01}.
Biotransformation:
Thirty minutes after administration of technetium Tc 99m apcitide, less than two thirds of the radioactivity circulating in plasma represented the parent drug, and only about 40% by six hours {01}. One of two unidentified metabolites (metabolite B), which represented less than 30% of the total radioactivity administered, has been detected in the urine; the other metabolite (metabolite A), which represented less than 10% of the total radioactivity, has been found in both plasma and urine {01}.
Half-life:
2 ± 0.5 hours following intravenous administration in adult patients (age range, 27 to 81 years) of 65 to 90 mcg of bibacitide containing 514.3 to 784.4 megabecquerels (13.9 to 21.2 millicuries) of technetium Tc 99m {01}.
Time to radioactivity visualization
Lower extremity imaging should begin between 10 and 60 minutes after technetium Tc 99m apcitide administration {01}. If repeated imaging is necessary, additional images may be obtained up to 180 minutes without reinjection {01}.
Radiation dosimetry:
{01}
| Estimated absorbed radiation dose * | ||
|---|---|---|
| Organ | mGy/MBq | rad/mCi |
| Urinary bladder wall | 0.06 | 0.22 |
| Kidneys | 0.014 | 0.05 |
| Large intestine wall (upper) | 0.01 | 0.039 |
| Large intestine wall (lower) | 0.01 | 0.037 |
| Uterus | 0.0092 | 0.034 |
| Ovaries | 0.0063 | 0.023 |
| Thyroid gland | 0.006 | 0.022 |
| Testes | 0.0053 | 0.02 |
| Lungs | 0.0043 | 0.016 |
| Red marrow | 0.0025 | 0.0091 |
| Breasts | 0.0013 | 0.005 |
| Effective dose: 0.0093 mSv/MBq (0.0034 rem/mCi) {01} | ||
Elimination:
Renal and biliary {01}. Approximately 75% of the administered activity is excreted in the urine within the first 8 hours {01}. Overall biliary excretion (total amount of radioactivity in the gastrointestinal tract and gallbladder) at approximately 24 hours after injection was 10.1 ± 2.5% of the administered activity {01}.
Precautions to Consider
Cross-sensitivity and/or related problems
Patients sensitive to peptide-based products may be sensitive to technetium Tc 99m apcitide also {01}.
Carcinogenicity
Studies to evaluate the carcinogenic potential of technetium Tc 99m apcitide have not been performed {01}.
Mutagenicity
Technetium Tc 99m apcitide was not mutagenic in the Ames test or mouse lymphoma test {01}. It was not clastogenic in the mouse micronucleus test {01}.
Pregnancy/Reproduction
Fertility—
Studies have not been done {01}.
Pregnancy—
Studies to assess transplacental transfer of technetium Tc 99m apcitide have not been done in humans {01}. Studies have not been done in animals {01}.
FDA Pregnancy Category C {01}.
Breast-feeding
Although it is not known whether technetium Tc 99m apcitide is distributed into breast milk, it is known that Tc 99m as free pertechnetate is distributed into breast milk {01}. Because of the potential risk to the infant from radiation exposure, breast-feeding should be discontinued and formula feedings used instead until technetium Tc 99m apcitide has been eliminated {01}.
Pediatrics
Appropriate studies on the relationship of age to the effects of technetium Tc 99m apcitide have not been performed in the pediatric population {01}.
Geriatrics
Appropriate studies on the relationship of age to the effects of technetium Tc 99m apcitide have not been performed in the geriatric population. However, clinical trials and studies that included older patients were conducted, and geriatrics-specific problems that would limit the usefulness of this agent in the elderly are not expected {01}.
Laboratory value alterations
The following have been selected on the basis of their potential clinical significance (possible effect in parentheses where appropriate)—not necessarily inclusive (» = major clinical significance):
With physiology/laboratory test values
Platelet aggregation{01} (may be decreased with doses higher than the clinical dose; however, the effect of technetium Tc 99m apcitide on bleeding time in humans has not been studied {01})
Medical considerations/Contraindications
The medical considerations/contraindications included have been selected on the basis of their potential clinical significance (reasons given in parentheses where appropriate)— not necessarily inclusive (» = major clinical significance).
Risk-benefit should be considered when the following medical problem exists
Sensitivity to peptide-based products or to the radiopharmaceutical preparation{01}
Side/Adverse Effects
The following side/adverse effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)—not necessarily inclusive:
Those indicating need for medical attention
Incidence rare
Hypotension —severe{01}
Those indicating need for medical attention only if they continue or are bothersome
Incidence less frequent
Headache —mild{01}
hypertension{01}
hypotension —mild{01}
pain —mild{01}
Patient Consultation
As an aid to patient consultation, refer to Advice for the the Patient, Radiopharmaceuticals (Diagnostic).
In providing consultation, consider emphasizing the following selected information (>> = major clinical significance):
Description of use
Action in the body: Localization of peptide complex in platelets found in thrombus; uptake of radioactivity may be visualized by external imaging
Small amounts of radioactivity used in diagnosis; radiation received is low and considered safe
Before having this test
» Conditions affecting use, especially:
Sensitivity to peptide-based products or to the radiopharmaceutical preparation
Pregnancy—Risk to fetus from radiation exposure as opposed to benefit derived from the study should be considered
Breast-feeding—Not known if technetium Tc 99m apcitide is distributed into breast milk, but Tc 99m (as free pertechnetate) is known to be distributed into breast milk; formula feedings should be used until the technetium Tc 99m has been eliminated to avoid any unnecessary absorbed radiation dose to the infant
Preparation for this test
Adequate intake of fluids and frequent voiding for the first few hours after administration of the agent, to minimize radiation exposure to the bladder
Precautions after having this test
» To prevent radiation contamination of other persons or environment: For the first 24 hours—
• Using a normal toilet instead of a urinal
• Double-flushing toilet
• Wiping any spilled urine with a tissue and flushing it away
• Washing hands with soap after using or cleaning toilet
• Immediately laundering clothes and linens soiled with urine or blood; washing them separately from other clothes
• Washing away any spilled blood
Notifying physician prior to administration if having an incontinence problem; catheterization may be required to prevent radiation contamination
General Dosing Information
Radiopharmaceuticals are to be administered only by or under the supervision of physicians who have had extensive training in the safe use and handling of radioactive materials and who are licensed by the Nuclear Regulatory Commission (NRC) or the appropriate Agreement State agency, if required, or, outside the U.S., the appropriate authority {01}.
The patient should increase intake of fluids and void frequently for the first few hours following the administration of technetium Tc 99m apcitide, to minimize radiation dose to the bladder {01}. Also, patient should void just before imaging in order to minimize the influence of urinary bladder radioactivity {01}.
Incontinent patients may require catheterization to prevent radiation contamination of the environment {01}.
For several hours after administration of technetium Tc 99m apcitide the patient should be observed for possible severe reactions, and competent personnel and emergency facilities should be available during this period {01}.
Safety considerations for handling this radiopharmaceutical
Guidelines for the receipt, storage, handling, dispensing, and disposal of radioactive materials are available from scientific, professional, state, federal, and international bodies. Handling of this radiopharmaceutical should be limited to those individuals who are appropriately qualified and authorized {01}.
Parenteral Dosage Forms
TECHNETIUM Tc 99m APCITIDE INJECTION USP
Usual adult administered activity
Diagnosis of acute deep venous thrombosis—
Intravenous, approximately 100 mcg of bibapcitide radiolabeled with 740 megabecquerels (20 millicuries) of technetium Tc 99m, administered into an upper extremity {01}.
Usual pediatric administered activity
Minimum dosage has not been established {01}.
Usual geriatric administered activity
See Usual adult administered activity .
Strength(s) usually available
U.S.—
100 mcg of bibapcitide, 75 mg of sodium glucoheptonate dihydrate, and 89 mcg of stannous chloride dihydrate in lyophilized form under nitrogen atmosphere, per vial (Rx) [AcuTect]
Note: Bibapcitide is composed of two apcitide monomers {01}. When the sodium pertechnetate Tc 99m injection is added to the vial and heated, the bibapcitide is split and forms a technetium Tc 99m–complex of apcitide {01}.
Packaging and storage:
Before radiolabeling, store between 2 and 8 °C (36 and 46 °F), unless otherwise specified by manufacturer {01}. Protect from light {01}.
Note: After radiolabeling, the technetium Tc 99m apcitide injection should be kept at room temperature {01}.
Preparation of dosage form:
To radiolabel the bibapcitide, a sterile, bacteriostatic- and oxidant-free sodium pertechnetate Tc 99m in 0.9% sodium chloride solution is used {01}. See the manufacturer's package insert for instructions.
Stability:
The package insert states that the injection should be administered within 6 hours after radiolabeling, since it does not contain a preservative {01}.
Caution:
Radioactive material.
Developed: 4/19/1999
References
- AcuTect package insert (Diatide—US), New 9/98.
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