Ammonia N-13
FDA Drug Information • Also known as: Ammonia N 13, Ammonia N-13
- Brand Names
- Ammonia N 13, Ammonia N-13
- Drug Class
- Radioactive Diagnostic Agent [EPC]
- Route
- INTRAVENOUS
- Dosage Form
- INJECTION
- Product Type
- HUMAN PRESCRIPTION DRUG
Description
11 DESCRIPTION 11.1 Chemical Characteristics Ammonia N 13 Injection is a positron emitting radiopharmaceutical that is used for diagnostic purposes in conjunction with positron emission tomography (PET) imaging. The active ingredient, [ 13 N] ammonia, has the molecular formula of 13 NH 3 with a molecular weight of 16.02, and has the following chemical structure: Ammonia N 13 Injection is provided as a ready to use sterile, pyrogen-free, clear and colorless solution. Each mL of the solution contains between 0.138 GBq to 1.387 GBq (3.75 mCi to 37.5 mCi) of [ 13 N] ammonia, at the end of synthesis (EOS) reference time, in 0.9% aqueous sodium chloride. The pH of the solution is between 4.5 to 7.5.The recommended dose of radioactivity (10-20 mCi) is associated with a theoretical mass dose of 0.5-1 picomoles (8.47-16.94 picograms) of ammonia. image description 11.2 Physical Characteristics Nitrogen N13 decays by emitting positron to Carbon C13 (stable) and has a physical half-life of 9.96 minutes. The principal photons useful for imaging are the dual 511 keV gamma photons that are produced and emitted simultaneously in opposite direction when the positron interacts with an electron (Table 2). Table 2: Principal Radiation Emission Data for Nitrogen 13 Radiation/Emission % Per Disintegration Energy Positron(β+) 100 1190 keV (Max.) Gamma(±)* 200 511 keV *Produced by positron annihilation The specific gamma ray constant (point source air kerma coefficient) for nitrogen N13 is 5.9 R/hr/mCi (1.39 x 10 -6 Gy/hr/kBq) at 1 cm. The half-value layer (HVL) of lead (Pb) for 511 keV photons is 4 mm. Selected coefficients of attenuation are listed in Table 3 as a function of lead shield thickness. For example, the use of 39 mm thickness of lead will attenuate the external radiation by a factor of about 1000. Table 3: Radiation Attenuation of 511 keV Photons by lead (Pb) shielding Shield Thickness (Pb) mm Coefficient of Attenuation 4 0.5 8 0.25 13 0.1 26 0.01 39 0.001 52 0.0001 Table 4...
What Is Ammonia N-13 Used For?
1 INDICATIONS AND USAGE Ammonia N 13 Injection is indicated for diagnostic Positron Emission Tomography (PET) imaging of the myocardium under rest or pharmacologic stress conditions to evaluate myocardial perfusion in patients with suspected or existing coronary artery disease. Ammonia N 13 Injection is a radioactive diagnostic agent for Positron Emission Tomography (PET) indicated for diagnostic PET imaging of the myocardium under rest or pharmacologic stress conditions to evaluate myocardial perfusion in patients with suspected or existing coronary artery disease ( 1 ).
Dosage and Administration
2 DOSAGE AND ADMINISTRATION Rest Imaging Study ( 2.1 ): Aseptically withdraw Ammonia N 13 Injection from its container and administer 10-20 mCi (0.368 – 0.736 GBq) as a bolus through a catheter inserted into a large peripheral vein. Start imaging 3 minutes after the injection and acquire images for a total of 10-20 minutes. Stress Imaging Study ( 2.2 ): If a rest imaging study is performed, begin the stress imaging study 40 minutes or more after the first Ammonia N13 injection to allow sufficient isotope decay. Administer a pharmacologic stress-inducing drug in accordance with its labeling. Aseptically withdraw Ammonia N 13 Injection from its container and administer 10-20 mCi (0.368 – 0.736 GBq) of Ammonia N 13 Injection as a bolus at 8 minutes after the administration of the pharmacologic stress-inducing drug. Start imaging 3 minutes after the Ammonia N 13 Injection and acquire images for a total of 10-20 minutes. Patient Preparation ( 2.3 ): To increase renal clearance of radioactivity and to minimize radiation dose to the bladder, hydrate the patient before the procedure and encourage voiding as soon as each image acquisition is completed and as often as possible thereafter for at least one hour. 2.1 Rest Imaging Study Aseptically withdraw Ammonia N 13 Injection from its container and administer 10-20 mCi (0.368 – 0.736 GBq) as a bolus through a catheter inserted into a large peripheral vein. Start imaging 3 minutes after the injection and acquire images for a total of 10-20 minutes. 2.2 Stress Imaging Study If a rest imaging study is performed, begin the stress imaging study 40 minutes or more after the first Ammonia N 13 injection to allow sufficient isotope decay. Administer a pharmacologic stress-inducing drug in accordance with its labeling. Aseptically withdraw Ammonia N 13 Injection from its container and administer 10-20 mCi (0.368 – 0.736 GBq) of Ammonia N 13 Injection as a bolus at 8 minutes after the administration of the pharmacologic stress-inducing drug. Start imaging 3 minutes after the Ammonia N 13 Injection and acquire images for a total of 10-20 minutes. 2.3 Patient Preparation To increase renal clearance of radioactivity and to minimize radiation dose to the bladder, ensure that the patient is well hydrated before the procedure and encourage voiding as soon as a study is completed and as often as possible thereafter for at least one hour. 2.4 Radiation Dosimetry The converted radiation absorbed doses in rem/mCi are shown in Table 1. These estimates are calculated from the Task Group of Committee 2 of the International Commission on Radiation Protection. 1 Table 1: N 13 Absorbed Radiation Dose Per Unit Activity (rem/mCi) for Adults and Pediatric Groups. Organ Adult 15 - year old 10 - year old 5 - year old 1 - year old Adrenals 0.0085 0.0096 0.016 0.025 0.048 Bladder wall 0.030 0.037 0.056 0.089 0.17 Bone surfaces 0.0059 0.0070 0.011 0.019 0.037 Brain 0.016 0.016 0.017 0.019 0.027 Breast 0.0067 0.0067 0.010 0.017 0.033...
Side Effects (Adverse Reactions)
6 ADVERSE REACTIONS No adverse reactions have been reported for Ammonia N 13 Injection based on a review of the published literature, publicly available reference sources, and adverse drug reaction reporting systems. However, the completeness of these sources is not known. No adverse reactions have been reported for Ammonia N 13 Injection based on a review of the published literature, publicly available reference sources, and adverse drug reaction reporting system ( 6). To report SUSPECTED ADVERSE REACTIONS, contact University of Wisconsin Radiopharmaceutical Production Facility at (608) 263-0359 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Drug Interactions
7 DRUG INTERACTIONS The possibility of interactions of Ammonia N 13 Injection with other drugs taken by patients undergoing PET imaging has not been studied.
Contraindications
4 CONTRAINDICATIONS None None ( 4 )
How Supplied
16 HOW SUPPLIED/STORAGE AND HANDLING Ammonia N 13 Injection is packaged in 10 mL mulitiple dose glass vial containing between 1.11 GBq to 11.1 GBq (30 mCi to 300 mCi) of [ 13 N] ammonia, at the end of synthesis (EOS) reference time, in 0.9% sodium chloride injection solution in approximately 8 mL volume. The recommended dose of radioactivity (10-20 mCi) is associated with a theoretical mass dose of 0.5-1 picomoles (8.47-16.94 picograms) of Ammonia. Storage Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F).Use the solution within 35 minutes of the End of Synthesis (EOS) calibration.
About This Information
This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.
What are side effects?
Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.
What are drug interactions?
Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.