What are the treatment options for Helicobacter pylori (H. pylori) infection in a patient allergic to penicillin (pcn)?

From the Guidelines

For patients with H. pylori infection who are allergic to penicillin, the recommended first-line regimen is a bismuth quadruple therapy consisting of a proton pump inhibitor, bismuth subsalicylate, tetracycline, and metronidazole for 14 days, as this regimen has been shown to be effective and is recommended by recent guidelines 1.

Treatment Options

The treatment options for H. pylori infection in patients allergic to penicillin include:

• Bismuth quadruple therapy: a proton pump inhibitor (such as omeprazole 20mg twice daily), bismuth subsalicylate (525mg four times daily), tetracycline (500mg four times daily), and metronidazole (500mg three times daily) for 14 days
• Levofloxacin-based triple therapy: a proton pump inhibitor (omeprazole 20mg twice daily), levofloxacin (500mg once daily), and clarithromycin (500mg twice daily) for 14 days, although this option is less preferred due to rising rates of levofloxacin resistance 1

Rationale

The bismuth quadruple therapy is preferred as the first-line regimen due to its effectiveness and recommendation by recent guidelines 1. The Toronto Consensus prefers this regimen based on its superiority over clarithromycin/metronidazole triple therapy in a prospective study.

Considerations

It is essential to confirm eradication with a urea breath test, stool antigen test, or endoscopic biopsy at least 4 weeks after completing therapy and while off proton pump inhibitors for at least 2 weeks.

Alternative Regimens

For patients with clarithromycin resistance, a regimen of a proton pump inhibitor, bismuth, tetracycline, and metronidazole is preferred. After two treatment failures, it is recommendable to empirically prescribe antibiotics not previously used, and whenever possible, to obtain gastric biopsy specimens to culture H. pylori and perform susceptibility testing 1.

From the FDA Drug Label

Adult Patients only Helicobacter pylori Infection and Duodenal Ulcer Disease: Triple therapy for Helicobacter pylori (H. pylori) with clarithromycin and lansoprazole : 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. Dual therapy for H. pylori with lansoprazole : Amoxicillin, in combination with lansoprazole delayed-release capsules as dual 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) who are either allergic or intolerant to clarithromycin or in whom resistance to clarithromycin is known or suspected.

For a patient allergic to penicillin (pcn), the treatment options for Helicobacter pylori (H. pylori) infection are limited due to the involvement of amoxicillin, a penicillin derivative, in the standard triple and dual therapy regimens.

• The triple therapy regimen, which includes amoxicillin, clarithromycin, and lansoprazole, may not be suitable for patients allergic to penicillin.
• The dual therapy regimen, which includes amoxicillin and lansoprazole, is also not suitable for patients allergic to penicillin. Given the information provided in the drug labels, there is no direct alternative treatment option mentioned for patients allergic to penicillin. Therefore, a conservative clinical decision would be to consult other resources or guidelines for alternative treatment options for H. pylori infection in patients with a penicillin allergy 2 3.

From the Research

Treatment Options for H. pylori Infection in Patients Allergic to Penicillin

• First-line treatment options for H. pylori infection in patients allergic to penicillin include:
  • A triple combination with a proton pump inhibitor (PPI), clarithromycin, and metronidazole 4, 5, 6
  • A quadruple therapy with PPI, bismuth, tetracycline, and metronidazole 4, 5, 6
• The efficacy of these first-line treatments varies, with the quadruple therapy (PPI + bismuth + tetracycline + metronidazole) showing higher eradication rates (91%) compared to the triple combination (PPI + clarithromycin + metronidazole) (69%) 6
• Second-line treatment options for patients who have failed first-line treatment include:
  • A quadruple regimen with PPI, bismuth, tetracycline, and metronidazole (if not previously prescribed) 6
  • A triple regimen with PPI, clarithromycin, and levofloxacin 4, 5, 6
• The efficacy of these second-line treatments also varies, with the quadruple regimen showing an eradication rate of 78% and the triple regimen with levofloxacin showing an eradication rate of 71% 6
• Third-line treatment options are also available, including the quadruple regimen with PPI, bismuth, tetracycline, and metronidazole, which showed an eradication rate of 75% in patients who had failed previous treatments 6

Considerations for Treatment Selection

• The choice of treatment should be based on the patient's specific circumstances, including their allergy to penicillin and any previous treatment failures 7, 8
• The presence of antibiotic resistance should also be considered when selecting a treatment regimen 7, 8
• The efficacy and safety of different treatment regimens should be carefully evaluated, taking into account the results of studies such as those cited here 4, 5, 6