Overview
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.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Ammonia N 13 Injection is a radiolabeled analog of ammonia that is distributed to all organs of the body after intravenous administration. It is extracted from the blood in the coronary capillaries into the myocardial cells where it is metabolized to glutamine N 13 and retained in the cells. The presence of ammonia N 13 and glutamine N 13 in the myocardium allows for PET imaging of the myocardium. 12.2 Pharmacodynamics Following intravenous injection, ammonia N 13 enters the myocardium through the coronary arteries. The PET technique measures myocardial blood flow based on the assumption of a three-compartmental disposition of intravenous ammonia N 13 in the myocardium.
Indications
- 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 ).
Common Doses
- Refer to label
Dosage
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.
Contraindications
- 4 CONTRAINDICATIONS None None ( 4 )
Side Effects
- 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).
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.