DIABACT UBT 50 MG TABLETS - summary of medicine characteristics

1 NAME OF THE MEDICINAL PRODUCT

Diabact UBT 50 mg tablets

2 QUALITATIVE AND QUANTITATIVE COMPOSITION

Each tablet contains 13C Urea 50 mg enriched stable isotope.

For the full list of excipients, see section 6.1.

3 PHARMACEUTICAL FORM

Tablets.

A white, round convex tablet.

4 CLINICAL PARTICULARS

4.1 Therapeutic indications

This medicinal product is for diagnostic use only.

For In vivo diagnosis of gastroduodenal primary or remaining Helicobacter pylori infection.

4.2 Posology and method of administration

Diabact UBT tablet is for oral administration.

One tablet as a single dose at one test occasion. The patient should fast for at least six hours preceding the test. An initial breath test sample is taken after which the tablet is swallowed whole with a glass of water. A breath sample is taken after ten minutes.

It is important to follow the instructions for use, described in section 6.6.

4.3 Contraindications

The test must not be used in patients with documented or suspected gastric infection that might interfere with the urea breath test.

Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.

4.4 Special warnings and precautions for use

A positive urea breath test alone does not clinically confirm that eradication therapy is indicated. Alternative diagnosis with invasive endoscopic methods might be indicated in order to examine the presence of any other complicating conditions, eg. gastric ulcer, autoimmune gastritis and malignancies.

The tablet must be swallowed whole. If the patient chews the tablet, the test must be performed again as the risk of false positive results increase. A new test may be performed the following day.

There are insufficient data to recommend the use of Diabact UBT in patients with partial gastrectomy and in patients younger than 18 years.

4.5 Interaction with other medicinal products and other forms of interaction The validity of the test result may be affected if the patient is currently being treated with antibiotics or a proton-pump inhibitor or has completed a course of treatment with these drugs. The results may be affected in general by all treatments interfering with H. pylori status or urease activity.

Suppression of H. pylori may lead to false negative results. Therefore, the test must not be used until after at least four (4) weeks after systemic antibacterial therapy and at least two (2) weeks after last dose of acid antisecretory agents. This is especially important after eradication therapy.

4.6 Fertility, Pregnancy and lactation

Pregnancy and breastfeeding

The endogenous production of urea amounts to 25 – 35 g/day. It is therefore unlikely that the dose of 50 mg urea should cause any adverse effects on pregnancy and lactation.

The Diabact UBT test is not expected to be harmful during pregnancy or to the health of the foetus/newborn child. Diabact UBT can be used during pregnancy and lactation.

4.7 Effects on ability to drive and use machines

Diabact UBT has no known or negligible influence on the ability to drive or to use machines.

4.8 Undesirable effects

Isolated reports of stomach pain, fatigue and distortion of the sense of smell (parosmia) have been reported in one clinical trial.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via Yellow Card Scheme

Website: www.mhra.gov.uk/yellowcard.

4.9 Overdose

Overdose is unlikely to occur in the intended clinical circumstances. No case of overdose has been reported.

5. PHARMACOLOGICAL PROPERTIES

5.1 Pharmacodynamic properties

Pharmacotherapeutic group: Other diagnostic agents, ATC code: V04CX05

Mechanism of action

After oral ingestion, 13C-urea labelled urea tablets will rapidly disintegrate on reaching the stomach. In the case of infection with H. pylori, 13C-urea is metabolised by the enzyme urease of H. pylori.

Enzyme urease

H2N(13CO)NH2 + H2O --------------►    2NH3 + 13CO2

The carbon dioxide which is liberated diffuses into the blood vessels and is transported as bicarbonate to the lungs where it is then liberated as 13CO2 in exhaled air. Infection with H. pylori will significantly change the 13C/12C – carbon isotope ratio.

The proportion of 13CO2 in the breath samples is determined by isotope-ratio-mass spectrometry (IRMS) or by another suitably-validated method carried out by any qualified laboratory and stated as an absolute difference (excess) in the value between a pre-urea and post-urea breath sample (see section 6.6).

The cut off point for discriminating between H. pylori positive and negative patients is based on a study with 885 patients. Values below 1.5^, i.e. <1.5^ are diagnosed as negative and values above i.e. >1.5^ are diagnosed as positive.

In order to determine test performance and to fulfil lack of direct comparison vs Standard of Truth (SoT) at the registered dose, a simulation analysis was carried out based on two comparative studies: the sensitivity was 94.3% (95% CI = [85.1% –98.5%]) and specificity was 97.1% (95% CI = [92.4% –99.2%]). The accuracy was 96.2% (95% CI = [92.2–98.5%]) and with the PPV (positive predicted value) of 94.0% (95% CI = [84.6–98.3%]) and NPV (negative predicted value) 97.3% (95% CI = [92.7–99.3%]).

5.2 Pharmacokinetic properties

Absorption

Urea is rapidly absorbed from the gastro-intestinal tract.

Distribution

Urea is distributed into extracellular and intracellular fluids including lymph, bile, cerebrospinal fluid and blood. It is reported to cross the placenta and penetrate the eye.

Elimination

Urea is excreted unchanged in the urine.

5.3 Preclinical safety data

There are no risks relevant for the clinical use of the product.

6 PHARMACEUTICAL PARTICULARS

6.1 List of excipients

Citric Acid, Anhydrous

Silica, Colloidal Anhydrous

Croscarmellose Sodium

Microcrystalline Cellulose

Magnesium Stearate

Talc

6.2 Incompatibilities

Not applicable.

6.3 Shelf life

4 years.

6.4 Special precautions for storage

Do not store above 25oC. Store in the original package.

6.5 Nature and contents of container

Diabact UBT pack sizes:

1 tablet (kit)

10 × 1 tablets (without sample tubes and disposable straw). Not all pack sizes may be marketed.