|Dosage Form||Package Information||Links|
|INJECTION, SOLUTION||1 INJECTION, SOLUTION in 1 PACKAGE (0270-0091-01)||Label Information|
Unintended radiation exposure occurs when the levels of Sr-82 or Sr-85 in the rubidium Rb 82 chloride injection exceed specified limits [see Warnings and Precautions (5.1)]
Perform generator eluate tests:
CardioGen-82 is a closed system used to produce rubidium Rb 82 chloride injection for intravenous use. Rubidium Rb 82 chloride injection is a radioactive diagnostic agent indicated for Positron Emission Tomography (PET) imaging of the myocardium under rest or pharmacologic stress conditions to evaluate regional myocardial perfusion in adult patients with suspected or existing coronary artery disease. (1)
CardioGen-82 consists of strontium Sr-82 adsorbed on a hydrous stannic oxide column with an activity of 90-150 millicuries Sr-82 at calibration time. (3)
To report SUSPECTED ADVERSE REACTIONS,
contact Bracco Diagnostics Inc at 1-800-257-5181
or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch (6)
See 17 for PATIENT COUNSELING INFORMATION.
CardioGen-82 is a closed system used to produce rubidium Rb 82 chloride injection for intravenous administration. Rubidium Rb 82 chloride injection is indicated for Positron Emission Tomography (PET) imaging of the myocardium under rest or pharmacologic stress conditions to evaluate regional myocardial perfusion in adult patients with suspected or existing coronary artery disease.
Use CardioGen-82 only with an infusion system specifically designed for use with the generator and capable of accurate measurement and delivery of doses of rubidium Rb 82 chloride injection. Follow instructions in the Infusion System Userâ€™s Guide for the set up and intravenous infusion of rubidium Rb 82 chloride injection dose(s).
Physical Decay Chart: Rb-82 half-life 75 seconds
|*Day of calibration|
Sr-85/Sr-82 Ratio Chart (Sr-85 T ½ = 65 days, Sr-82 ½ = 25 days)
|Days||Ratio Factor||Days||Ratio Factor||Days||Ratio Factor|
|Table 3 Adult Absorbed Radiation Dose Coefficient|
(Average for Rest and Stress)
|aRb-82 doses are averages of rest and stress dosimetry data (see Senthamizhchelvan et al. 1,2). To calculate organ doses (mrem) from Rb-82, multiply the dose coefficient for each organ by the administered activity in mCi.
bSr-82 and Sr-85 doses are calculated using software package DCAL and ICRP dose coefficients. To calculate organ doses (mrem) attributable to Sr-82, and Sr-85, multiply the dose coefficients by the calculated amounts of strontium in µCi.3
cTo convert to SI units, insert the dose coefficient into the formula in parentheses, e.g. for adrenals 7.56 mrem/mCi = 7.56 µSv/37 MBq = 2.04 x 10-13 Sv/Bq .
dCalculated from ICRP 66
eCalculated from ICRP 60
fStress phase only
|Bone â€“ Osteogenic cells||1.86||---||---|
|Gall Bladder Wall||3.17||8.47||2.82|
|Lower Large Intestine Wall||2.84||51.8||5.14|
|Upper Large Intestine||5.94||23.7||3.62|
|Urinary Bladder Wall||1.61||21.9||2.90|
|Total Body||1.77||Not Calculated||Not Calculated|
Unintended radiation exposure occurs when the Sr-82 and Sr-85 levels in rubidium Rb 82 chloride injections exceed the specified generator eluate limits. Unintended exposure to strontium radiation has occurred in some patients who received rubidium Rb 82 injections at clinical sites where generator eluate testing appeared insufficient. The physical half lives of Sr-82 and Sr-85 are 25 days and 65 days, respectively, in contrast to Rb-82 which has a physical half-life of 75 seconds. Unintended exposure to strontium radiation contributes to a patientâ€™s overall cumulative radiation dose [see Warnings and Precautions (5.4)].
To minimize the risk of unintended radiation exposure, strict adherence to a daily eluate testing protocol is required. Stop using the rubidium generator when the expiration limits are reached [see Dosage and Administration (2.5) and (2.6)].
Pharmacologic induction of cardiovascular stress may be associated with serious adverse reactions such as myocardial infarction, arrhythmia, hypotension, bronchoconstriction, and cerebrovascular events. Perform pharmacologic stress testing in accordance with the pharmacologic stress agentâ€™s prescribing information and only in the setting where cardiac resuscitation equipment and trained staff are readily available.
Patients with congestive heart failure or the elderly may experience a transitory increase in circulatory volume load. Observe these patients during infusion and for several hours following rubidium chloride injection administration to detect delayed hemodynamic disturbances.
Rubidium Rb 82 chloride injection, similar to other radiopharmaceuticals, contributes to a patientâ€™s overall long-term cumulative radiation exposure. Long-term cumulative radiation exposure is associated with an increased risk of cancer. Use the lowest dose of rubidium Rb 82 chloride injection necessary for imaging and ensure safe handling to protect the patient and health care worker [see Dosage and Administration (2.2) and (2.3)]. Encourage patients to void as soon as a study is completed and as often as possible thereafter for at least one hour.
The following serious adverse reactions have been identified during postapproval use of CardioGen-82. 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.
Unintended radiation exposure has occurred in some patients who received rubidium Rb 82 chloride injections at clinical sites where generator eluate testing appeared insufficient [see Boxed Warning, Warnings and Precautions (5.1), and Dosage and Administration (2.5)].
Animal reproductive studies have not been conducted with rubidium Rb 82 chloride injection. It is also not known whether rubidium Rb 82 chloride injection can cause fetal harm when administered to a pregnant woman; however, all radiopharmaceuticals have the potential to cause fetal harm depending on the fetal stage of development and the magnitude of the radiation dose. If considering rubidium Rb 82 chloride injection administration to a pregnant woman, inform the patient about the potential for adverse pregnancy outcomes based on the radiation dose from rubidium Rb-82 and the gestational timing of exposure. Administer rubidium Rb-82 to a pregnant woman only if clearly needed.
It is not known whether rubidium Rb 82 chloride injection is excreted in human milk. Due to the short half-life of rubidium Rb-82 (75 seconds) it is unlikely that the drug would be excreted in human milk during lactation. However, because many drugs are excreted in human milk, caution should be exercised when rubidium Rb-82 chloride injection is administered to nursing women. Do not resume breastfeeding until one hour after the last infusion.
In elderly patients with a clinically important decrease in cardiac function, lengthen the delay between infusion and image acquisition [see Dosage and Administration (2.2)]. Observe for the possibility of fluid overload [see Warnings and Precautions (5.3)].
Reductions in renal function are not anticipated to alter clearance of rubidium Rb 82 chloride injection because Rb-82 decays to stable Kr-82 with a half-life of 75 seconds and Kr-82 is exhaled through the lungs.
CardioGen-82 contains accelerator-produced Sr-82 adsorbed on stannic oxide in a lead-shielded column and provides a means for obtaining sterile nonpyrogenic solutions of rubidium Rb 82 chloride injection. The chemical form of Rb-82 is 82RbCl.
The amount (millicuries) of Rb-82 obtained in each elution will depend on the potency of the generator.
When eluted at a rate of 50 mL/minute, each generator eluate at the end of elution should not contain more than 0.02 microcurie of Sr-82 and not more than 0.2 microcurie of Sr-85 per millicurie of rubidium Rb 82 chloride injection, and not more than 1 microgram of tin per mL of eluate.
Rb-82 decays by positron emission and associated gamma emission with a physical half-life of 75 seconds.4 Table 4 shows the annihilation photons released following positron emission which are useful for detection and imaging studies.
The decay modes of Rb-82 are: 95.5% by positron emission, resulting in the production of annihilation radiation, i.e., two 511 keV gamma rays; and 4.5% by electron capture, resulting in the emission of â€œpromptâ€ gamma rays of predominantly 776.5 keV. Both decay modes lead directly to the formation of stable Kr-82.4
Principal Radiation Emission Data
|Mean Percent||Mean Energy|
|Annihilation photons (2)||191.01||511 (each)|
The specific gamma ray constant for Rb-82 is 6.1 R/hour-millicurie at 1 centimeter. The first half-value layer is 0.7 centimeter of lead (Pb). Table 5 shows a range of values for the relative attenuation of the radiation emitted by this radionuclide that results from interposition of various thicknesses of lead.5 For example, the use of a 7.0 centimeter thickness of Pb will attenuate the radiation emitted by a factor of about 1,000.
Radiation Attenuation by Lead Shielding
|Shield Thickness (Pb) cm||Attenuation Factor|
Physical Decay Chart: Sr-82 half-life 25 days
To correct for physical decay of Rb-82, Table 1 shows the fraction of Rb-82 remaining in all 15 second intervals up to 300 seconds after time of calibration [see Dosage and Administration (2.5)].
Rb-82 is analogous to potassium ion (K+) in its biochemical behavior and is rapidly extracted by the myocardium proportional to the blood flow. Rb+ participates in the sodium-potassium (Na+/K+) ion exchange pumps that are present in cell membranes. The intracellular uptake of Rb-82 requires maintenance of ionic gradient across cell membranes. Rb-82 radioactivity is increased in viable myocardium reflecting intracellular retention, while the tracer is cleared rapidly from necrotic or infarcted tissue.
In human studies, myocardial activity was noted within the first minute after peripheral intravenous injection of Rb-82. When areas of infarction or ischemia are present in the myocardium, they are visualized within 2-7 minutes after injection as photon-deficient, or â€œcoldâ€, areas on the myocardial scan.
In patients with reduced cardiac function, transit of the injected dose from the peripheral infusion site to the myocardium may be delayed [see Dosage and Administration (2.2)].
Blood flow brings Rb-82 to all areas of the body during the first pass of circulation. Accordingly, visible uptake is also observed in other highly vascularized organs, such as the kidneys, liver, spleen and lungs.
With a physical half-life of 75 seconds, Rb-82 is very rapidly converted by radioactive decay into a trace amount of stable Kr-82 gas, which is passively expired by the lungs. Renal and hepatic excretion is not anticipated to play an essential role in Rb-82 elimination, although some of the Rb-82 dose may be excreted in the urine prior to radioactive decay.
In a descriptive, prospective, blinded image interpretation study6 of adult patients with known or suspected coronary artery disease, myocardial perfusion deficits in stress and rest PET images obtained with ammonia N 13 (n = 111) or rubidium Rb-82 chloride (n = 82) were compared to changes in stenosis flow reserve (SFR) as determined by coronary angiography. PET perfusion defects at rest and stress for seven cardiac regions (anterior, apical, anteroseptal, posteroseptal, anterolateral, posterolateral, and inferior walls) were graded on a scale of 0 (normal) to 5 (severe). Values for stenosis flow reserve, defined as flow at maximum coronary vasodilatation relative to rest flow, ranged from 0 (total occlusion) to 5 (normal). With increasing impairment of flow reserve, the subjective PET defect severity increased. A PET defect score of 2 or higher was positively correlated with flow reserve impairment (SFR<3).
A systematic review of published literature was conducted using pre-defined inclusion/exclusion criteria which resulted in identification of 10 studies evaluating the use of Rb-82 PET myocardial perfusion imaging (MPI) for the identification of coronary artery disease as defined by catheter-based angiography. In these studies, the patient was the unit of analysis and 50% stenosis was the threshold for clinically significant coronary artery disease (CAD). Of these 10 studies, 9 studies were included in a meta-analysis for sensitivity (excluding one study with 100% sensitivity) and 7 studies were included in a meta-analysis of specificity (excluding 3 studies with 100% specificity). A random effects model yielded overall estimates of sensitivity and specificity of 92% (95% CI: 89% to 95%) and 81% (95% CI: 76% to 86%), respectively. The use of meta-analysis in establishing performance characteristics is limited, particularly by the possibility of publication bias (positive results being more likely to be published than negative results) which is difficult to detect especially when based on a limited number of small studies.
CardioGen-82®(rubidium Rb 82 generator) consists of Sr-82 adsorbed on a hydrous stannic oxide column with an activity of 90-150 millicuries Sr-82 at calibration time. A lead shield surrounded by a labeled plastic container encases the generator. The container label provides complete assay data for each generator. Directions for determining the activity of Rb-82 eluted from the generator are described above [see Dosage and Administration (2.5)]. Use CardioGen-82 (rubidium Rb 82 Generator) only with an appropriate, properly calibrated infusion system labeled for use with the generator.
Receipt, transfer, handling, possession or use of this product is subject to the radioactive material regulations and licensing requirements of the U.S. Nuclear Regulatory Commission, Agreement States or Licensing States as appropriate.
Licensee personnel should monitor the amount of radioactivity present within the generator prior to its disposal. Do not dispose of the generator in regular refuse systems. Store and/or dispose of the generator in accordance with the conditions of NRC radioactive materials license pursuant to 10 CFR, Part 20, or equivalent conditions pursuant to Agreement State Regulation. For questions about the disposal of the CardioGen-82 generator, contact Bracco Diagnostics Inc. at 1-800-447-6883, option 3.
rubidium chloride rb-82 injection, solution
|Labeler - Bracco Diagnostics Inc (849234661)|
|Registrant - Bracco Diagnostics Inc (849234661)|
|GE HEALTHCARE INC.||154129886||MANUFACTURE(0270-0091)|
|Nordion (Canada) Inc||201112088||API MANUFACTURE(0270-0091)|