bismuth subcitrate potassium + metronidazole + tetracycline hydrochloride: clinical use

Prescribing considerations

• Confirm an appropriate H. pylori-associated ulcer indication and concurrent omeprazole prescription.
• Review renal and hepatic status, neurological disease, blood dyscrasia, myasthenia gravis, interacting medicines and alcohol use.
• Use in older people requires particular attention to organ function, comorbidity and polypharmacy.
• It is not recommended for adolescents aged 12 to 18 years.
• Advise about oesophageal protection, photosensitivity, harmless stool darkening and neurological warning symptoms.

Contraindications and cautions

• Pregnancy or breastfeeding
• Renal or hepatic impairment
• Age under 12 years
• Hypersensitivity to any active substance, another nitroimidazole or an excipient
• Cockayne syndrome

Monitoring

• Review promptly if neurological symptoms, severe diarrhoea, candidiasis, photosensitivity or a severe rash develops.
• Monitor coagulation with warfarin or another coumarin anticoagulant.
• Monitor lithium concentrations when clinically necessary.
• Monitor ciclosporin concentration and serum creatinine if coadministration is unavoidable.
• Metronidazole can interfere with some laboratory assays, and bismuth can affect gastrointestinal X-ray procedures.
• For severe infection or treatment failure, consider microbiological confirmation and susceptibility assessment.

Clinical pharmacology

Bismuth has local antimicrobial and anti-adhesion effects, metronidazole damages bacterial DNA after reductive activation, and tetracycline inhibits 30S ribosomal protein synthesis.

Formulation and product differences

• The selected UK product is a hard capsule containing powder and a smaller inner capsule.
• It contains lactose, potassium and gelatin.
• It is supplied in a moisture-protective bottle with a desiccant, which must not be swallowed.

Capsule

Route: Oral

Strengths: 140 mg + 125 mg + 125 mg