First‑Line Treatment of Helicobacter pylori Infection

Preferred Regimen – Bismuth Quadruple Therapy (BQT)

The Toronto, Maastricht V/Florence, and ACG consensus statements identify BQT as the most universally recommended first‑line option for treatment‑naïve adults when antibiotic susceptibility is unknown. 1
BQT consists of a proton‑pump inhibitor (PPI) twice daily, bismuth four times daily, metronidazole 500 mg three‑to‑four times daily, and tetracycline 500 mg four times daily. [1][2]
A 14‑day course is required for optimal eradication. 1
This regimen remains effective in regions with high dual resistance to clarithromycin and metronidazole, and it retains acceptable success even when in‑vitro metronidazole resistance is present. 1

Recommended when bismuth is unavailable or in settings of high clarithromycin resistance; it combines a PPI twice daily, amoxicillin 1000 mg twice daily, metronidazole 500 mg twice daily, and clarithromycin 500 mg twice daily. 1
The regimen should be administered for 14 days. 1

Offered as an empiric alternative for patients without penicillin allergy; it includes rifabutin 150 mg twice daily, amoxicillin 1 g three times daily, and a high‑dose PPI (≥40 mg omeprazole‑equivalent twice daily or 20 mg rabeprazole/esomeprazole twice daily). 2
Treatment duration is 14 days. 2
Resistance to rifabutin is reported to be rare, providing a theoretical advantage. 2

The Toronto, Maastricht V/Florence, and ACG consensus groups limit use of clarithromycin‑based triple therapy to regions where clarithromycin resistance is documented to be < 15 %. 1
In most areas, rising clarithromycin resistance makes this regimen unsuitable for empiric therapy. 1

All first‑line regimens must be given for 14 days; the Toronto Consensus strongly recommends this length because it yields higher eradication rates than shorter courses. 1

High‑dose PPIs are required (minimum 40 mg omeprazole‑equivalent twice daily, or equivalent dosing of rabeprazole/esomeprazole). Adequate acid suppression is essential for the efficacy of the accompanying antibiotics. 2

Levofloxacin‑containing regimens should be reserved for rescue therapy, not first‑line use. 1
Sequential and hybrid therapies are now considered obsolete because they add antibiotics that do not improve outcomes and promote antimicrobial resistance. 2
Substituting doxycycline for tetracycline in BQT results in significantly lower eradication rates and should be avoided. 2
Ten‑day regimens are not recommended unless local data demonstrate equivalence to a 14‑day course. 1

In the usual scenario lacking individual susceptibility testing, clinicians should choose among BQT, concomitant therapy, or rifabutin triple therapy based on the patient’s prior antibiotic exposure and the known local resistance patterns. 1