How Should We Treat?
Despite use of the currently most effective treatment regimens, approximately 10% to 20% of patients will fail to achieve eradication of their infection, and thus will remain H pylori positive. Because retreatment is always difficult, choosing the best available first-line treatment regimen still represents the best rescue strategy. However, in designing a treatment strategy, we should not focus on the results of primary therapy alone. An adequate strategy for treating this infection should employ 2 therapies that, if applied consecutively, come as close to a 100% cure rate as possible.
The choice of second-line treatment depends on which treatment approach was used initially, because retreatment with the same regimen is not recommended. If a clarithromycin-based regimen was used initially, a metronidazole-based regimen should be used as follow-up (in combination with a PPI, tetracycline, and bismuth), and vice versa. Prolonging the treatment period to 14 days is probably necessary. Because bacterial resistance to metronidazole or clarithromycin results primarily from previous treatment failures, first-choice treatment should never combine clarithromycin and metronidazole in the same regimen. In fact, even though this combination is highly effective, patients who are not cured will have at least single, and usually double, resistance, and no viable empirical treatment remains afterwards. If an empirical (ie, nonsusceptibility testing-based) treatment is chosen, the performance of a test culture after first eradication failure is not necessary; in clinical practice, assessment of the sensitivity of H pylori to antibiotics is suggested only after failure of second-line treatment.
First-line therapy should be a PPI-based triple therapy employing a PPI (standard dose twice daily) combined with clarithromycin (500 mg twice daily) and amoxicillin (1 g twice daily), for a minimum of 7 days. Second-line therapy should be quadruple therapy with a PPI (standard dose twice daily), bismuth salt (subsalicylate or subcitrate 120 mg 4 times daily), metronidazole (500 mg thrice daily) and tetracycline (500 mg 4 times daily) for 14 days. Further failures should be managed by specialists. The Table summarizes the suggested therapeutic regimens for eradication of H pylori infection.
What rescue regimen should be used after initial treatment failure? Recently, rifabutin-based rescue therapies (twice-daily standard-dose PPI plus amoxicillin 1 g twice daily or levofloxacin 500 mg once daily plus rifabutin 300 mg daily, for 7 days) have been shown to represent an encouraging strategy for eradication failures because they are effective against H pylori strains resistant to clarithromycin or metronidazole.[27,28] However, rifabutin is very costly, and concerns still remain about the widespread use of this drug because of the possibility for accelerating development of drug resistance. Results of a recent study suggest that a 10-day rescue therapy regimen based on the use of rabeprazole (20 mg twice daily) plus amoxicillin (1 g twice daily) plus levofloxacin (500 mg once daily) is more effective than standard quadruple regimen as a second-line option for H pylori eradication. Additionally, a 7-day quadruple-therapy regimen containing amoxicillin and tetracycline has recently been proven more effective than standard quadruple therapy with metronidazole and tetracycline to rescue failed triple therapy, by overcoming the antimicrobial resistance of H pylori.
© 2004 Medscape
Cite this: Eradication of Helicobacter pylori: A Clinical Update - Medscape - Feb 18, 2004.