C-14 Urea

What it is and how it works

Helicobacter pylori produces urease, which hydrolyses ingested 14C-urea into ammonia and 14C-labelled carbon dioxide. The labelled CO2 is absorbed and exhaled, and its detection in breath samples indicates active H. pylori infection.

Indications

Non-invasive diagnosis of gastric Helicobacter pylori infection and confirmation of eradication after treatment.

Dosage and administration (summary)

Administered as a single oral capsule (low activity, typically about 37 kBq) according to the test protocol, followed by breath sample collection at the specified time.

Contraindications

Pregnancy and breast-feeding; children (non-radioactive 13C-urea tests are preferred in these groups).

Warnings and precautions

False-negative results may occur if proton-pump inhibitors are taken within about 2 weeks, or antibiotics or bismuth compounds within about 4 weeks before the test; testing should be performed fasting. Radiation dose is very low, but the radioactive product must be handled and disposed of according to regulations.

Pregnancy

Not recommended in pregnancy; the 13C-urea breath test should be used instead.

Storage and supply

Store at room temperature (below 25 °C) in accordance with radioactive-materials regulations.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.