What is the next step for a patient with a positive H. pylori (Helicobacter pylori) antigen test after treatment?

From the Guidelines

After a positive H. pylori antigen test following treatment, the patient should undergo a confirmatory test to verify eradication, typically performed 4-8 weeks after completing therapy, using the urea breath test, stool antigen test, or in some cases, endoscopy with biopsy, as recommended by the most recent guidelines 1. The preferred testing methods include the urea breath test, stool antigen test, or in some cases, endoscopy with biopsy.

• It's crucial to avoid antibiotics for 4 weeks and proton pump inhibitors (PPIs) for 2 weeks before testing to prevent false negative results.
• If H. pylori is still present, a second-line treatment regimen should be initiated, usually consisting of a different antibiotic combination such as bismuth quadruple therapy (bismuth subsalicylate, tetracycline, metronidazole, and a PPI) for 14 days, as suggested by recent studies 1. This second treatment approach is necessary because H. pylori may have developed resistance to the initial antibiotics used.
• Persistent infection increases the risk of peptic ulcer disease, gastric cancer, and other gastrointestinal complications, making confirmation of eradication essential for long-term health outcomes, as highlighted in recent research 1. The optimal duration of H. pylori therapy is 14 days, and therapies should be susceptibility-based, relying either on susceptibility testing or on proven high local success rates, as recommended by the most recent guidelines 1.
• Success should always be confirmed by a test of cure after treatment of every patient, providing an indirect measure of resistance/susceptibility in the population. The prevalence of antibiotic resistance has increased, and clarithromycin, metronidazole, or fluoroquinolone triple therapies can no longer be used empirically, but they remain effective when susceptibility has been confirmed, as noted in recent studies 1.

From the FDA Drug Label

Patients not eradicated of H. pylori following omeprazole/clarithromycin/amoxicillin triple therapy or omeprazole/clarithromycin dual therapy will likely have clarithromycin resistant H. pylori isolates.

The next step for a patient with a positive H. pylori antigen test after treatment is to consider clarithromycin resistance and potentially switch to a different treatment regimen.

• Retreatment options may include an alternative antibiotic regimen, such as a bismuth-based quadruple therapy or a levofloxacin-based triple therapy.
• Clarithromycin susceptibility testing should be done, if possible, to confirm resistance and guide further treatment decisions.
• It is essential to consult the prescribing information for the specific antibiotics being used and consider seeking guidance from a specialist, such as a gastroenterologist, for further management 2.

From the Research

Next Steps for H. pylori Antigen Positive After Treatment

• The patient should undergo further testing to confirm the presence of H. pylori, as a positive antigen test after treatment may indicate treatment failure or reinfection 3.
• The choice of test may be influenced by the patient's use of proton pump inhibitors (PPIs), as PPIs can cause false-negative results in some tests 3, 4.
• If the patient is taking PPIs, it may be necessary to stop the medication for 2 weeks before testing to ensure accurate results 3.
• The stool antigen test (SAT) may be a useful alternative to other tests, as it is less likely to be affected by PPI use 4.
• If the patient is found to still be infected with H. pylori, a different treatment regimen may be necessary, such as a quadruple therapy regimen including two antibiotics and a PPI 5, or a high-dose PPI and long-acting clarithromycin regimen 6.
• The patient's CYP2C19 genotype may also be a factor in determining the best course of treatment, as some genotypes may be more resistant to certain antibiotics 7.

Considerations for Treatment Failure

• Treatment failure may be due to antibiotic resistance, and antibiotic susceptibility testing may be necessary to determine the best course of treatment 6, 7.
• The use of high-dose PPIs and long-acting clarithromycin may be effective in patients with certain CYP2C19 genotypes 6.
• Re-treatment with a different regimen, such as a dual high-dose lansoprazole-amoxicillin therapy, may be effective in patients who have failed initial treatment 7.