Technetium Tc 99m Pyrophosphate

Technescan PYP, after radiolabeling with sodium pertechnetate Tc 99m, is indicated for:

• Skeletal imaging to demonstrate areas of altered osteogenesis in adults
• Cardiac imaging as an adjunct in the diagnosis of acute myocardial infarction in adults (See WARNINGS ) Technescan PYP, in conjunction with sodium pertechnetate Tc 99m injection for red blood cell (RBC) labeling, is indicated for gated cardiac blood pool imaging and for the detection of gastrointestinal bleeding sites in adults.

None known.

Image interpretation errors can occur. As an adjunct in the diagnosis of confirmed myocardial infarction (ECG and serum enzymes positive), the estimate of false negative image interpretations was 6%. False negative image interpretations can occur if made too early in the evolutionary phase of the infarct or too late in the resolution phase. In a study involving 22 patients in whom ECG was positive and serum enzymes questionable or negative, but in whom the final diagnosis of acute myocardial infarction was made, the estimates of false negative and false positive image interpretations were 23% and 9%, respectively. False positive image interpretations have been reported following coronary artery bypass graft surgery and in unstable angina pectoris, old myocardial infarcts, and cardiac contusions. Technetium Tc 99m pyrophosphate may impair brain imaging with sodium pertechnetate Tc 99m and result in false positive or false negative image interpretation. It is recommended, where feasible, that brain imaging precede skeletal imaging procedures. Gated cardiac blood pool and gastrointestinal bleed imaging may be impaired in patients receiving sodium heparin for anticoagulant therapy. This is characterized by a reduction in the amount of injected radioactivity remaining in the blood pool. Avoid heparinized catheter systems for administration of Technescan PYP. The biodistribution of technetium Tc 99m pyrophosphate may be altered in the presence of high levels of certain cations (iron, calcium, and aluminum). This may result in reduced uptake of radionuclide in the skeleton and increased extraosseal uptake, which may potentially degrade imaging quality. High levels of these cations may be caused by concomitant medications or medical conditions (e.g., iron overload, hypercalcemia, etc.). Most cases are observed after iron infusion. (See PRECAUTIONS, Drug Interactions .)

General Technetium Tc 99m pyrophosphate 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 drug handling to protect patients and healthcare providers from unintentional radiation exposure. (See DOSAGE AND ADMINISTRATION, Radiation Safety-Drug Handling .) Advise patients to drink fluids before and after administration and to void as often as possible after administration to reduce unnecessary exposure to radiation. Drug Interactions The biodistribution of technetium Tc 99m pyrophosphate may be altered in the presence of high levels of certain cations (iron, calcium, and aluminum). This may result in reduced uptake of radionuclide in the skeleton and increased extraosseal uptake, which may potentially degrade imaging quality. In patients with high levels of these cations caused by concomitant medications, particularly patients receiving iron infusions, consider performing an imaging study with technetium Tc 99m pyrophosphate injection once the cation levels have normalized (e.g., after 3 to 5 half-lives of the cation). (See WARNINGS .) Carcinogenesis, Mutagenesis, Impairment of Fertility No long-term animal studies have been performed to evaluate carcinogenic or mutagenic potential, or whether this drug affects fertility in males or females. Pregnancy Animal reproduction studies have not been conducted with Technetium Tc 99m Pyrophosphate Injection. It is also not known whether this drug can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. All radiopharmaceuticals, including Technescan PYP, have the potential to cause fetal harm depending on the fetal stage of development and the magnitude of the radiation dose. If considering Technescan PYP administration to a pregnant woman, inform the patient about the potential for adverse pregnancy outcomes based on the radiation dose from technetium Tc 99m pyrophosphate and the gestational timing of exposure. Nursing Mothers Technetium-99m is excreted in human milk during lactation, therefore, formula feedings should be substituted for breast feeding. Pediatric Use Safety and effectiveness in pediatric patients have not been established. Geriatric Use Of the 137 subjects included in clinical studies of Technescan PYP labeled with technetium-99m for skeletal imaging, 28 subjects (20%) were 65 to 74 years of age, and 21 (15%) were 75 years of age and older. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences between elderly and younger patients. This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

The following adverse reactions associated with the use of Technescan PYP have been reported: flushing, hypotension, fever, chills, nausea, vomiting, and dizziness, as well as hypersensitivity reactions such as itching and various skin rashes.

The biodistribution of technetium Tc 99m pyrophosphate may be altered in the presence of high levels of certain cations (iron, calcium, and aluminum). This may result in reduced uptake of radionuclide in the skeleton and increased extraosseal uptake, which may potentially degrade imaging quality. In patients with high levels of these cations caused by concomitant medications, particularly patients receiving iron infusions, consider performing an imaging study with technetium Tc 99m pyrophosphate injection once the cation levels have normalized (e.g., after 3 to 5 half-lives of the cation). (See WARNINGS .)

Animal reproduction studies have not been conducted with Technetium Tc 99m Pyrophosphate Injection. It is also not known whether this drug can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. All radiopharmaceuticals, including Technescan PYP, have the potential to cause fetal harm depending on the fetal stage of development and the magnitude of the radiation dose. If considering Technescan PYP administration to a pregnant woman, inform the patient about the potential for adverse pregnancy outcomes based on the radiation dose from technetium Tc 99m pyrophosphate and the gestational timing of exposure.

Technetium-99m is excreted in human milk during lactation, therefore, formula feedings should be substituted for breast feeding.

Safety and effectiveness in pediatric patients have not been established.

Of the 137 subjects included in clinical studies of Technescan PYP labeled with technetium-99m for skeletal imaging, 28 subjects (20%) were 65 to 74 years of age, and 21 (15%) were 75 years of age and older. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences between elderly and younger patients. This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.