H. Pylori Treatment Regimens Without Bismuth
For H. pylori eradication without bismuth, concomitant non-bismuth quadruple therapy (PPI, amoxicillin, metronidazole, and clarithromycin) for 14 days is the recommended first-line regimen in areas of high clarithromycin resistance. 1
First-Line Non-Bismuth Regimens
Concomitant Non-Bismuth Quadruple Therapy (PAMC)
This is the preferred non-bismuth containing regimen:
- PPI (standard dose) twice daily
- Amoxicillin 1000 mg twice daily
- Metronidazole 500 mg twice daily
- Clarithromycin 500 mg twice daily
- Duration: 14 days 1
This regimen is recommended by all major guidelines (Toronto Consensus, Maastricht V/Florence, and ACG) as a first-line option when bismuth is not available, particularly in areas with high clarithromycin resistance 1.
PPI Triple Therapy (PAC or PMC)
Can be considered in areas with low clarithromycin resistance (<15-20%):
- PPI (standard dose) twice daily
- Amoxicillin 1000 mg twice daily OR metronidazole 500 mg twice daily
- Clarithromycin 500 mg twice daily
- Duration: 14 days 1
However, this regimen has declining efficacy due to increasing clarithromycin resistance and is now restricted by all guidelines 1.
Levofloxacin Triple Therapy (PAL)
- PPI (standard dose) twice daily
- Amoxicillin 1000 mg twice daily
- Levofloxacin 500 mg once daily or 250 mg twice daily
- Duration: 14 days 1
This regimen is suggested by ACG as a first-line option but is generally not recommended by other guidelines as first-line therapy due to concerns about increasing levofloxacin resistance 1.
Optimizing Treatment Success
PPI Dosing
- Use high-dose PPI (double standard dose) to increase efficacy 1
- Standard PPI doses: dexilant 30 mg, esomeprazole 20 mg, lansoprazole 30 mg, omeprazole 20 mg, pantoprazole 40 mg, rabeprazole 20 mg 1
- Take PPI 30 minutes before eating on an empty stomach 1
Duration of Therapy
All guidelines recommend 14-day treatment for most regimens to maximize eradication rates. The Toronto Consensus and Maastricht V/Florence guidelines specifically recommend 14 days for all first-line treatments 1.
Special Considerations
- For patients with penicillin allergy: Consider clarithromycin-based triple therapy with metronidazole if no prior exposure to macrolides and from an area of low clarithromycin resistance 1
- For patients who have failed previous therapy: Avoid re-using antibiotics that failed previously, particularly clarithromycin and levofloxacin 1
Second-Line Options Without Bismuth
If first-line therapy fails:
- Levofloxacin triple therapy (PAL) is recommended if the patient has not previously received levofloxacin 1
- High-dose dual therapy can be considered:
- Rabeprazole 20 mg four times daily
- Amoxicillin 750 mg four times daily
- Duration: 14 days 1
Common Pitfalls to Avoid
Underestimating antibiotic resistance: Local resistance patterns significantly impact treatment success. In areas with high clarithromycin resistance (>15-20%), avoid clarithromycin triple therapy without susceptibility testing 1.
Insufficient treatment duration: 14-day regimens are superior to shorter courses for most treatments 1.
Improper PPI dosing: Using standard-dose rather than high-dose PPI can reduce efficacy. Double-dose PPI is often recommended to increase eradication success 1.
Poor patient compliance: Complex regimens with multiple medications can lead to poor adherence. Twice-daily dosing of amoxicillin has been shown to be as effective as four-times-daily dosing and may improve compliance 2.
Reusing failed antibiotics: Particularly clarithromycin and levofloxacin, as resistance develops rapidly after exposure 1.
After two failed therapies with confirmed patient adherence, H. pylori susceptibility testing should be considered to guide the selection of subsequent regimens 1.