Randomized study of two "rescue" therapies for Helicobacter pylori-infected patients after failure of standard triple therapies

Impact of furazolidone-based quadruple therapy for eradication of Helicobacter pylori after previous treatment failures

BACKGROUND

One week of quadruple therapy including metronidazole is recommended for Helicobacter pylori treatment failures after first line therapy regardless of resistance status. This study investigated whether a quadruple regimen containing furazolidone could be effective as a third-line (salvage) therapy.

METHODS

All patients with previous H. pylori treatment failure after a clarithromycin-metronidazole +/- amoxicillin combination plus acid suppression were given lansoprazole 30 mg twice a day (bid), tripotassiumdicitratobismuthate 240 mg bid, tetracycline 1 g bid, metronidazole 400 mg (PPI-B-T-M) three times a day (tid) for 1 week. In the case of treatment failure with this second-line therapy, the same regimen was applied for 1 week except for using furazolidone 200 mg bid (PPI-B-T-F) instead of metronidazole (sequential study design).

RESULTS

Eighteen consecutive patients were treated with PPI-B-T-M. Eleven of those 18 remained H. pylori positive (38.9% cured). Pretherapeutic metronidazole resistance was associated with a lower probability of eradication success (10% vs. 75%, p=.04). Ten of these 11 patients agreed to be retreated by PPI-B-T-F. Final cure of H. pylori with PPI-B-T-F was achieved in 9/10 patients (90%) nonresponsive to PPI-B-T-M.

CONCLUSIONS

In the presence of metronidazole resistance, PPI-B-T-M as a recommended second-line therapy by the Maastricht consensus conference achieved unacceptable low cure rates in our metronidazole pretreated population. In this population, metronidazole based second-line quadruple therapy may be best suited in case of a metronidazole-free first line-regimen (e.g. PPI-clarithromycin-amoxicillin) or a low prevalence of metronidazole resistance. Furazolidone in the PPI-B-T-F combination does not have a cross-resistance potential to metronidazole and is a promising salvage option after a failed PPI-B-T-M regimen.

Rescue Therapy for Helicobacter pylori

Up to 35% of patients infected with Helicobacter pylori fail to respond to standard anti-H. pylori therapy. With the rising prevalence antimicrobial resistance, the failure rates of conventional proton pump inhibitor-containing triple therapy are expected to increase. Pretreatment antibiotic resistance testing should be done whenever possible to allow for tailoring of the treatment regimens. The data on second-line or rescue therapy are limited and usually are subjected to various biases and confounding factors. Switching between clarithromycin and metronidazole should be considered if repeated courses of proton pump inhibitor-containing triple therapy are used as second-line therapy in the absence of antimicrobial sensitivity testing. The prolongation of therapy duration with proton pump inhibitor, amoxicillin, and clarithromycin is ineffective for clarithromycin-resistant strains. The bismuth-containing quadruple therapy is the best salvage treatment in the absence of pretreatment antibiotic susceptibility. Furazolidone quadruple therapy (where available) and rifabutin triple therapy are salvage therapies of last resort. If these regimens fail, culture and susceptibility testing is required.

Update on the management of Helicobacter pylori infection, including drug-resistant organisms

Helicobacter pylori infection has many different clinical outcomes. Not all infected persons need to be treated. Therefore, indications for treatment have to be clear, and several consensus guidelines have been formulated to aid the medical practitioner in this decision-making process. Triple therapy with a proton pump inhibitor (PPI), in combination with amoxicillin and clarithromycin is the established treatment of choice. For patients with penicillin hypersensitivity, metronidazole can be substituted for amoxicillin. Bacterial resistance to antibiotics is a major factor adversely affecting treatment success. Resistance to metronidazole has been reported in up to 80%, and resistance to clarithromycin in 2-10% of strains cultured. Resistance to either one of the antibiotics has been reported to result in a drop in efficacy of up to 50%. Emergence of resistance to both metronidazole and clarithromycin following failed therapy is a cause for concern; this underlines the need to use the best available first-line therapy. To avoid the emergence of resistance to both key antibiotics, the combination of metronidazole and clarithromycin should be avoided where possible. For failed treatment, several strategies can be employed. These include ensuring better compliance with repeat therapy, and maximizing the efficacy of repeat treatment by increasing dosage and duration of treatment, as well as altering the choice of drugs. Quadruple therapy incorporating a bismuth compound with a PPI, tetracycline and metronidazole has been a popular choice as a "rescue" therapy. Ranitidine bismuth citrate has been shown to be able to overcome metronidazole and clarithromycin resistance; it may be a useful compound drug to use in place of a PPI in "rescue" therapies. In the case of persistent treatment failures, it is useful to consider repeating gastroscopy and obtaining tissue for culture, and then prescribe antibiotics according to bacterial susceptibility patterns. It is also important in refractory cases to review the original indication for treatment and determine the importance of the indication.

Amoxicillin/tetracycline combinations are inadequate as alternative therapies for Helicobacter pylori infection

BACKGROUND

Triple therapy with proton pump inhibitors or ranitidine bismuth citrate, clarithromycin and either amoxicillin or nitroimidazole derivatives are the present gold standards for cure of Helicobacter pylori infection. However, primary resistance to either clarithromycin or nitroimidazole derivatives is increasing and alternative therapies are needed.

AIM

To determine the efficacy and safety of three regimens consisting of amoxicillin and tetracycline or doxycycline combined with either lansoprazole or ranitidine bismuth citrate.

METHODS

Two hundred and seventy H. pylori infected patients were randomly given one of the following treatments: amoxicillin 1 g twice a day (b.i.d.) plus tetracycline 500 mg four times a day (q.i.d.) with either lansoprazole 30 mg b.i.d. (group LAT) or ranitidine bismuth citrate 400 mg b.i.d. (group RBCAT) for 7 days and amoxicillin 1 g b.i.d. plus doxycycline 100 mg b.i.d. and lansoprazole 30 mg b.i.d. for 14 days (group LAD). Eradication rate was assessed by UBT at 4-6 weeks after therapy.

RESULTS

The three groups (LAT, RBCAT, and LAD) of patients achieved eradication rates of 35% (25-45), 20% (12-29) and 36% (25-46), respectively, on intention-to-treat analysis. Patient compliance was optimal and side-effects minimal in all three groups.

CONCLUSIONS

Although the amoxicillin/tetracycline combination is attractive (inexpensive, safe, and with low primary resistance rate), it can not be recommended for H. pylori eradication.

Efficacy of Helicobacter pylori eradication therapies: a single centre observational study

BACKGROUND

Many Helicobacter pylori eradication regimens have been described. There are little data reporting their efficacy or integration in routine clinical practice. The overall results of eradication therapy in a cohort of patients are described and an algorithm for management outlined.

METHODS

469 patients receiving eradication therapy in routine clinical practice were evaluated. The successes of individual regimes as first, second and third line therapy were determined.

RESULTS

Overall success after one, two and three courses of therapy were 73% (95% confidence intervals 69-77%), 94% (91-96%) and 98% (97-99%) respectively. 10 different regimens, including many non-recommended ones were used as primary therapy. Ranitidine bismuth citrate-amoxicillin-clarithromycin triple therapy (94.8%, 90-99%) was significantly more effective than any other combination as primary therapy, including all proton pump inhibitor based triple therapies. Quadruple therapy with bismuth chelate-proton pump inhibitor-tetracycline and a nitroimidazole (70%, 52-88%) and ranitidine bismuth citrate-based triple therapy (73%, 56-90%) where more effective second line combinations than proton pump inhibitor-triple therapies (37.5%, 12-58%). Third line therapy directed by the results of sensitivity testing improved eradication compared to further empirical antibiotics. The use of a proton pump inhibitor with clarithromycin and a nitroimidazole as initial therapy was associated with a significantly worse overall eradication rate than other combinations.

CONCLUSIONS

Helicobacter pylori eradication rates can be maximised by using ranitidine bismuth citrate-clarithromycin-amoxicillin containing triple therapy, followed by bismuth and nitroimidazle containing second-line therapy, with third line combinations directed by sensitivity testing. Proton pump inhibitor-clarithromycin-metronidazole combinations should be avoided.