In short
Bismuth oxide is an investigational medicine being studied as part of a fixed-dose combination tablet for Helicobacter pylori infection. The combination also contains metronidazole and tetracycline hydrochloride, and is being compared against standard first-line therapy in one authorised Phase 3 trial involving 420 participants.
Bismuth oxide is an investigational medicine being studied as part of a fixed combination tablet for Helicobacter pylori infection. The combination also contains metronidazole and tetracycline hydrochloride, and is being compared against standard first-line therapy in one authorised Phase 3 trial involving 420 participants.
Key points
- Bismuth oxide is being tested as part of a three-drug fixed combination tablet for Helicobacter pylori infection.
- The single registered trial is a Phase 3 study with 420 participants, currently authorised.
- The trial compares the combination against standard first-line therapy using a non-inferiority design.
- The main measure is successful clearance of the infection, confirmed by a negative urea breath test.
- Bismuth oxide is also found in existing haemorrhoid preparations such as Anusol cream and ointment.
- The study is sponsored by Verisfield SMSA and the product is given as a film-coated tablet by mouth.
What is bismuth oxide?
Bismuth oxide is a chemical substance that is used in medicines. In the product records for the trial described on this page, it is part of a fixed combination with metronidazole and tetracycline hydrochloride, supplied as a film-coated tablet for oral use. The combination product is called Metronidazole + Bismuth oxide + Tetracycline hydrochloride / Verisfield f.c. tablet, and the company responsible for supplying the product is Verisfield SMSA. The substance has no marketing authorisation in these product records, meaning it is still an investigational substance for this use.
Bismuth oxide is not a new substance in medicine. It is already found in several products used to treat haemorrhoids, including Anusol cream, Anusol ointment and Anusol HC preparations, where it is combined with other ingredients such as zinc oxide, bismuth subgallate, benzyl benzoate and hydrocortisone acetate. The dm+d browser lists eight virtual medicinal products containing bismuth oxide, all of them in the Anusol and Hemocane range. The Devon Formulary also lists a compound haemorrhoidal preparation containing bismuth oxide with benzyl benzoate, bismuth subgallate, hydrocortisone acetate, peru balsam and zinc oxide.
How does bismuth oxide work?
The mechanism of action of bismuth oxide in Helicobacter pylori infection is not described in the sources available for this page. Bismuth compounds are known to have antibacterial properties, but the specific way bismuth oxide works in the combination being studied is not stated in the trial record or the supplementary sources.
What the trial record does state is the objective of the study: to demonstrate that the fixed combination containing bismuth oxide is not inferior to standard first-line therapy for clearing Helicobacter pylori infection. This means the researchers want to show that the new combination works at least as well as the treatment doctors currently use first.
Which conditions is bismuth oxide used or studied for?
- Helicobacter pylori infection — the condition studied in the Phase 3 trial, where the aim is to clear the infection from the stomach.
- Haemorrhoids — bismuth oxide is already used in several over-the-counter and prescription products for haemorrhoids, such as Anusol cream and ointment.
How is bismuth oxide given?
In the clinical trial, bismuth oxide is given as part of a fixed combination film-coated tablet that is taken by mouth (oral use). The combination contains metronidazole, bismuth oxide and tetracycline hydrochloride in a single tablet. The trial record does not state the dose of bismuth oxide used, only that the tablet is given orally.
In existing haemorrhoid products, bismuth oxide is used in creams, ointments and suppositories that are applied locally to the anal area.
What do the clinical trials show?
There is one registered clinical trial investigating bismuth oxide as part of a fixed combination for Helicobacter pylori infection. The trial is a Phase 3 study, which means it is at a late stage of development, testing the treatment in a larger group of people after earlier phases have suggested it may be effective.
The study is currently authorised, meaning it has received approval to proceed but has not yet started recruiting or treating participants. It is an interventional study, which means participants receive a specific treatment and are then followed up.
The trial is designed to include 420 participants. Participants will receive either the fixed combination containing bismuth oxide, metronidazole and tetracycline hydrochloride, or the standard first-line therapy. The standard therapy in the trial consists of Flagyl (metronidazole), Amoxil (amoxicillin), Klaricid (clarithromycin) and Helides (esomeprazole), which is a proton pump inhibitor used to reduce stomach acid.
The primary outcome measure is the successful clearance of the infection, defined as a negative urea breath test after completing the eradication treatment. The urea breath test is a way of checking whether Helicobacter pylori is still present in the stomach: the patient drinks a solution containing urea, and if the bacteria are present they break down the urea and release a gas that can be detected in the breath. The trial will compare the eradication rate between the two treatment groups in the microbiological intention-to-treat set, which includes all participants who had the infection confirmed at the start.
The trial also uses a product called Helicobacter Test INFAI, which is a powder for oral solution used to perform the urea breath test.
What side effects are known?
The trial record and the supplementary sources provided do not describe specific side effects of bismuth oxide in the combination being studied. No safety information from the trial is available in the data on this page, and the supplementary sources do not list side effects for the haemorrhoid products containing bismuth oxide.