What are the indications for oral antibiotics in the treatment of gastritis?

From the Guidelines

Oral antibiotics are only recommended for gastritis caused by Helicobacter pylori (H. pylori) infection, and the choice of antibiotics should be guided by local resistance patterns and patient factors. For H. pylori-associated gastritis, the standard treatment is triple therapy consisting of two antibiotics (usually amoxicillin 1000mg twice daily and clarithromycin 500mg twice daily) plus a proton pump inhibitor (PPI) such as omeprazole 20mg twice daily for 10-14 days, as recommended by the Maastricht IV/Florence consensus report 1. However, in areas with high clarithromycin resistance, bismuth-containing quadruple treatments are recommended for first-line empirical treatment 1.

Some key points to consider when treating H. pylori-associated gastritis include:

• The use of high-dose (twice a day) PPI increases the efficacy of triple therapy 1
• Extending the duration of PPI-clarithromycin-containing triple treatment from 7 to 10-14 days improves the eradication success by approximately 5% and may be considered 1
• PPI-clarithromycin-metronidazole (PCM) and PPI-clarithromycin-amoxicillin (PCA) regimens are equivalent 1
• After failure of a PPI-clarithromycin containing therapy, either a bismuth containing quadruple therapy or Levofloxacin containing triple therapy are recommended 1

It's also important to note that rising rates of Levofloxacin resistance should be taken into account when choosing an antibiotic regimen 1, and that after failure of second-line treatment, treatment should be guided by antimicrobial susceptibility testing whenever possible 1. The urea breath test or a laboratory-based validated monoclonal stool test are both recommended as non-invasive tests for determining the success of eradication treatment 1.

More recent guidelines also emphasize the importance of reconciling recent H. pylori treatment guidelines in a time of increasing resistance to antibiotics 1, highlighting the need for tailored treatment approaches based on local resistance patterns and patient factors.

In summary, the treatment of H. pylori-associated gastritis should be individualized based on local resistance patterns, patient factors, and the presence of any underlying conditions that may affect treatment outcomes, and should always prioritize the use of evidence-based antibiotic regimens to minimize the risk of antibiotic resistance and treatment failure 1.

From the FDA Drug Label

Amoxicillin, in combination with clarithromycin plus lansoprazole as triple therapy, is indicated for the treatment of patients with H pylori infection and duodenal ulcer disease (active or 1-year history of a duodenal ulcer) to eradicate H. pylori. Omeprazole and clarithromycin dual therapy and omeprazole, clarithromycin and amoxicillin triple therapy have been shown to be active against most strains of Helicobacter pylori in vitro and in clinical infections

Oral Antibiotics for Gastritis:

• Amoxicillin can be used in combination with other medications to treat gastritis caused by H. pylori infection.
• Triple therapy with amoxicillin, clarithromycin, and a proton pump inhibitor (such as lansoprazole or omeprazole) is effective in eradicating H. pylori and reducing the risk of duodenal ulcer recurrence.
• The dosage and duration of treatment with amoxicillin may vary depending on the severity of the infection and the patient's age and weight 2, 3.

From the Research

Oral Antibiotics for Gastritis

• The use of oral antibiotics for gastritis, particularly for the eradication of Helicobacter pylori (H. pylori), has been extensively studied 4, 5, 6, 7.
• A combination of a proton pump inhibitor (PPI) such as omeprazole with amoxicillin and clarithromycin is considered one of the most effective treatments for H. pylori eradication 4.
• Studies have shown that the eradication rate of H. pylori using a 1-week course of famotidine, amoxicillin, and clarithromycin is around 90.4% 4.
• Another study found that a 1-week course of omeprazole, clarithromycin, and amoxicillin resulted in an eradication rate of 89.6% 5.
• Quadruple therapy regimens, which add amoxicillin to the standard triple therapy, have also been shown to be effective in eradicating H. pylori, with eradication rates ranging from 91% to 96% 6.
• The use of high-dose PPI and long-acting clarithromycin has also been found to improve eradication rates, particularly in areas with low clarithromycin resistance 7.
• It is essential to note that the increasing resistance to key antibiotics used in H. pylori eradication demands antibiotic susceptibility testing, surveillance of resistance, and antibiotic stewardship 8.

Treatment Regimens

• The following treatment regimens have been studied:
  • Famotidine, amoxicillin, and clarithromycin for 1 week 4
  • Omeprazole, clarithromycin, and amoxicillin for 1 or 2 weeks 5
  • Quadruple therapy with omeprazole, metronidazole, clarithromycin, and amoxicillin for 5 days 6
  • High-dose PPI and long-acting clarithromycin for 7 or 14 days 7

Eradication Rates

• The eradication rates for the studied treatment regimens are:
  • 90.4% for famotidine, amoxicillin, and clarithromycin for 1 week 4
  • 89.6% for omeprazole, clarithromycin, and amoxicillin for 1 week 5
  • 91% to 96% for quadruple therapy with omeprazole, metronidazole, clarithromycin, and amoxicillin for 5 days 6
  • 100% for high-dose PPI and long-acting clarithromycin for 14 days 7