Summary of UK- NICE guidance for treatment of Helicobacter infection-

NICE recommends a one week triple therapy regimen as first-line eradication therapy.

The optimum regimen consists of a full dose proton pump inhibitor, with either amoxicillin 1g and clarithromycin 500mg or metronidazole 400mg and clarithromycin 250mg, all given twice daily.

Efficacy
Eradication is effective in 80-85% of patients on triple therapy using either antibiotic combination.

Dual therapies are not as effective as triple therapy and are not recommended.
Triple therapy using a proton pump inhibitor plus amoxicillin and metronidazole is no longer recommended.

Resistance
Combinations with metronidazole and clarithromycin used as first-line therapy may induce resistance to both antibiotics whereas amoxicillin resistance does not seem to increase after the use of amoxicillin and clarithromycin combinations.
If clarithromycin or metronidazole has previously been taken for any infection in the past year, do not use that antibiotic in the triple therapy regimen, as monotherapy with these agents very readily leads to resistance.

First-line therapy
Metronidazole and clarithromycin combination should be used in patients with penicillin hypersensitivity.
Clarithromycin 250mg twice daily is as effective as 500mg twice daily when combined with metronidazole.

Second-line therapy
Quadruple therapy containing bismuth is as effective as triple therapy and is sometimes recommended as second-line therapy (treatment failure).
If quadruple therapy is not tolerated consider triple therapy that contains antibiotics not used before.
Second-line therapy should use different antibiotics to first-line therapy.

G Mohan.