Urea (14C)
Urea (14C) Uses, Dosage, Side Effects, Food Interaction and all others data.
Urea 14C is a urea molecule radiolabelled with a radioactive carbon-14. It is currently used for the Urea Breath Test (UBT) and is available as a rapid diagnostic test (marketed as PyTest) for the detection of Helicobacter pylori infections. H pylori is a common stomach bacteria that has been linked to a variety of upper gastrointestinal disorders such as gastritis, gastric and peptic ulcers, stomach cancer, and gastric mucosa-associated lymphoid-tissue (MALT) lymphoma. The UBT is indicated to confirm H. pylori infection and to monitor post-treatment for its eradication.
Radiolabelled urea is available in two forms as 13C and 14C. Both forms can be used within the Urea Breath Test, however some may prefer 13C as it is non-radioactive compared to 14C, which may be preferable in pregnant women and children.
The Urea Breath Test is based on the ability of the H. pylori enzyme urease to cleave urea into ammonia and carbon dioxide. As the urease enzyme is not present in mammalian cells, the presence of urease (and the products of urea cleavage) in the stomach is evidence that H. pylori bacteria are present. To detect H. pylori, urea labeled with 14C is swallowed by the patient. If gastric urease from H. pylori is present, urea is split to form CO2 and NH3 at the interface between the gastric epithelium and lumen and 14CO2 is absorbed into the blood and exhaled in the breath. Exhaled breath samples can then be collected and measured for the presence of radioactivity.
| Trade Name | Urea (14C) |
| Generic | Urea C-14 |
| Urea C-14 Other Names | 14C-urea, Carbon 14 urea, Carbon-14 urea, Urea (14C), Urea 14 C, Urea C 14, Urea-14C, Urea, C-14 |
| Type | |
| Formula | CH4N2O |
| Weight | Average: 62.048 Monoisotopic: 62.035604745 |
| Groups | Approved |
| Therapeutic Class | |
| Manufacturer | |
| Available Country | |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Urea (14C) is a diagnostic agent used for the detection of urease associated with Helicobacter pylori in the human stomach and initial diagnosis or post-treatment monitoring of Helicobacter pylori infection in adults.
14C-urea is intended for use in the detection of gastric urease as an aid in the diagnosis of Helicobacter pylori (H. pylori) infection in the human stomach. The test utilizes a liquid scintillation counter for the measurement of 14CO2 in breath samples.
Urea (14C) is also used to associated treatment for these conditions: Helicobacter Pylori Infection
How Urea (14C) works
The urease enzyme is not present in mammalian cells, so the presence of urease in the stomach is evidence that bacteria are present. The presence of urease is not specific for H. pylori, but other bacteria are not usually found in the stomach. To detect H. pylori, urea labeled with 14C is swallowed by the patient. If gastric urease from H. pylori is present, urea is split to form CO2 and NH3 at the interface between the gastric epithelium and lumen and 14CO2 is absorbed into the blood and exhaled in the breath. Following ingestion of the capsule by a patient with H. pylori, 14CO2 excretion in the breath peaks between 10 and 15 minutes and declines thereafter with a biological half-life of about 15 minutes. Therefore, the detection of isotope-labelled carbon dioxide in exhaled breath indicates that urease is present in the stomach, and hence that H. pylori bacteria are present.
Food Interaction
- Take on an empty stomach. Avoid eating and drinking for 4-6 hours before doing a urea breath test with Urea (14C).
Half Life
14C-urea that is not hydrolyzed by H. pylori is excreted in the urine with a half-life of approximately 12 hours. About 10% of the 14C remains in the body at 72 hours and is gradually excreted with a biological half-life of 40 days.
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