What is the recommended treatment regimen for H pylori infection using Flagyl (metronidazole)?

From the Guidelines

The recommended treatment regimen for H. pylori infection using Flagyl (metronidazole) is a concomitant therapy approach, consisting of clarithromycin 500mg bid, amoxicillin 1g bid, metronidazole 500 mg bid, and a PPI bid for 14 days, as outlined in the 2021 AGA clinical practice update 1.

Treatment Regimens

The treatment regimens for H. pylori infection can vary, but the concomitant therapy approach is a recommended option. The regimens include:

• Bismuth quad: bismuth 300mg qid, metronidazole 500mg tid, tetracycline 500mg qid, PPI bid for 14 days
• Concomitant: clarithromycin 500mg bid, amoxicillin 1g bid, metronidazole or tinidazole 500 mg bid, PPI bid for 14 days
• Clarithromycin triple: clarithromycin 500mg bid, amoxicillin 1g bid or metronidazole 500 mg bid, PPI bid for 14 days

Proton Pump Inhibitor (PPI) Dosage

The standard dose for PPIs is as follows: pantoprazole 40mg, lansoprazole 30mg, omeprazole 20mg, esomeprazole 20mg, dexlansoprazole 30mg, rabeprazole 20mg. The optimal dosing is 30 minutes prior to eating or drinking on an empty stomach, without concomitant use of other anti-acids (e.g. histamine-2 receptor antagonists) 1.

Considerations

Treatment success depends on antibiotic resistance patterns, which vary geographically, so local resistance rates should be considered when selecting therapy. Patients should complete the entire course of antibiotics even if symptoms improve before completion. Side effects of metronidazole may include metallic taste, nausea, and a disulfiram-like reaction with alcohol, so patients should avoid alcohol during treatment and for at least 48 hours after completing metronidazole. Confirmation of H. pylori eradication with a urea breath test, stool antigen test, or endoscopic biopsy is recommended at least 4 weeks after completing therapy and after PPI discontinuation for at least 2 weeks.

From the Research

Treatment Regimen for H pylori with Flagyl (Metronidazole)

• The recommended treatment regimen for H pylori infection using Flagyl (metronidazole) is typically a triple therapy consisting of two antibiotics, including metronidazole, and a proton pump inhibitor (PPI) 2.
• A study published in 1995 found that a combination therapy of metronidazole, omeprazole, and clarithromycin was effective in treating H pylori infection, with a cure rate of 88% 3.
• Another study published in 1998 found that a one-week, twice-daily, PPI-based triple therapy regimen eradicated about 90% of H pylori and was associated with mild side effects 4.
• A quadruple therapy regimen consisting of amoxicillin, metronidazole, omeprazole, and clarithromycin has also been shown to be effective in eradicating H pylori, with a cure rate of 96% in patients without previous dual therapy and 92% in patients with previous dual therapy 5.
• A study published in 2008 found that the combination of a PPI plus amoxicillin and metronidazole provided excellent eradication rates after initial treatment failure with a PPI plus amoxicillin and clarithromycin, with an overall eradication rate of 91.1% 6.

Factors Affecting Treatment Success

• Antibiotic resistance is a major cause of treatment failure, with metronidazole resistance reducing the eradication rate by approximately 40% 6.
• Patient compliance is also an important factor in treatment success, with non-compliance leading to reduced eradication rates 2.
• The choice of PPI may not significantly affect the eradication rate, with similar results seen with rabeprazole, lansoprazole, and omeprazole 6.