Q&A with Professor Varocha Mahachai—Strategies and treatment options in combating H. pylori antibiotic resistance

During her poster presentation, Professor Varocha Mahachai (VM) fielded a number of questions about her study from fellow physicians and other delegates. Her answers are summarized below:

What is the reason for the decline of eradication rates with standard triple therapy? How can we improve H. pylori treatment outcomes?

VM: The eradication rate of standard triple therapy has dropped to below 80% worldwide, which is suboptimal. The main reason is antimicrobial resistance. It is important to know the resistance pattern in a particular location in order to choose the right antibiotics for optimal therapy. Resistance patterns are geographically unique as they are influenced by local doctors’ prescription habits and local patients’ genetic makeup, among other factors. Alternative and rescue therapies are required to improve the treatment outcome.

What is the role of levofloxacin, a second line therapeutic agent, in the fight against H. pylori infection?

VM: In patients who have failed first-line therapy, the H. pyloristrains tend to have high resistance to antibiotics, thus posing a clinical challenge for eradication. Levofloxacin-based second-line therapy can be used as the rescue therapy after failure of first-line therapy. Although the eradication rate associated with levofloxacin-based second-line therapy is only around 63%, the cumulative eradication rate reaches 90%. Extending the duration of therapy from 10 to 14 days may result in a higher eradication rate.

In addition, levofloxacin based triple therapy can be considered as a rescue therapy in locations where bismuth is not available.

What is the optimal duration of levofloxacin-based treatment?

VM: It is different according to countries. Some guidelines (eg, Second Asia-Pacific Consensus Guidelines) recommend a 7-day treatment but an extension to a 10-day treatment is being considered, which is similar to the recommendation in the Maastricht IV/Florence Consensus Report used in Europe. In the United States, the recommendation is a 14-day regimen. Extending treatment duration to 14 days may increase the eradication rate, but it really depends on how well the patient can tolerate the side effects of the longer regimen schedule.

Has levofloxacin-based triple therapy been shown to increase patient compliance and should it be considered as first-line treatment?

VM: Levofloxacin-based triple therapy is a simple regimen—levofloxacin is given only once a day, and amoxicillin and a PPI only twice a day—and is generally well tolerated, so it should be easy for most patients to comply. However, we need more data to support its use as a first-line treatment.

How important are factors such as H. pylori strains, genetic polymorphisms and age in determining treatment options and predicting treatment outcomes in patients?

VM: There is currently no evidence to suggest that any of these factors can influence treatment outcome. Some studies suggested that IL1-polymorphism may be associated with gastric atrophy, resulting in reduced acid secretion and higher eradication rate. On the contrary, CYP2C19 polymorphism may affect the activity of PPIs, thus reducing eradication rate. Increasing the dose of PPI in a regimen to overcome rapid metabolism is an option for increasing eradication rate.

For patients who have failed both first-and second-line treatments, what are the options?

VM: We do not have many studies on third-line treatments after second-line treatment failure. Alternative therapies include bismuth-based quadruple therapy and sequential/concomitant treatment with different combination of antibiotics; treatment will need to be individualized depending on the doctor’s therapeutic choices and the patient’s tolerability profile.

It is important to note that once H. pylori is successfully eradicated, most patients will remain recurrence free. Education is therefore essential to help patients understand the consequence of H. pyloriinfection so as to increase their incentive to actively seek treatment for permanent cure.