Bismuth subcitrate potassium with metronidazole and tetracycline hydrochloride

How it works

It combines the topical mucosal and antibacterial action of bismuth with two antibacterials, metronidazole and tetracycline, to eradicate Helicobacter pylori, and is co-prescribed with a proton pump inhibitor to raise gastric pH and enhance efficacy.

Prescribing in practice

• Patients must be warned to avoid alcohol during metronidazole-containing therapy and for a period afterwards because of the risk of a disulfiram-like reaction.
• The tetracycline component contraindicates use in pregnancy, breastfeeding and young children owing to effects on developing teeth and bone, and dairy products and antacids should be separated from dosing as they impair tetracycline absorption.
• Completion of the full course is essential to achieve eradication and limit antibacterial resistance.

Monitoring

Routine laboratory monitoring is not required, but confirm eradication after treatment where indicated and review for adverse effects.

Counselling the patient

• Take every dose and finish the whole course to clear the infection.
• Avoid alcohol during treatment and for a short time afterwards.
• Expect the bismuth to darken your stools and tongue, which is harmless.

Evidence & guidelines

Bismuth-based quadruple therapy is recommended in NICE guidance as a Helicobacter pylori eradication regimen, particularly after previous treatment failure.