Tag Archives: Helicobacter pylori

Understanding Resistance to Helicobacter pylori

Posted on by

An editorial (by Ben Gold -congratulations!) helps sort out the potential advantages of gene based testing for Helicobacter pylori in a commentary on a recent publication (JPGN 2014;  59: 6-9).

In the study, the authors used formalin=fixed biopsies in 38 H pylori--infected gastric biopsies.  These specimens were examined for 23S rRNA mutations associated with resistance to clarithromycin.  Overall, the authors (from Dallas, TX) noted H pylori in 4.5% of their biopsies.  The majority of these children, treated between 2010-2012, were given clarithromycin, amoxicillin, and a proton pump inhibitor (n=25).  Due to clarithromycin resistance, this is no longer considered a first-line treatment in the absence of clarithromycin susceptibility testing according to NASPGHAN guidelines (published in 2011).

The authors noted a cure rate of 62.5%, likely due to the use of clarithromycin-based triple therapy.  In addition, Dr. Gold notes that the authors identified a very high rate of clarithromycin resistance (50%): “greater than that reported by any of the previously published national surveys or single-center studies in the United States, Europe, or Japan.”

Take-home point from Dr. Gold: “Because the common mutations responsible for H pylori resistance to the other major antimicrobials used for eradication…have been described, the assay developed by Mittui et al could be modified to include a panel of antibiotics…to optimize therapy.”

Related blog posts:

What is Evidence-Based Medicine for Helicobacter Pylori?

Posted on by

Full article (Clin Gastroenterol Hepatol 2014; 12: 177-86): http://ow.ly/sPKbi 

My take on the most important parts of this Helicobacter pylori (HP) article:

  • Success defined: curing HP ≥95% =excellent, curing HP ≥90% =good, acceptable ≥85%, and unsatisfactory <85%.
  • “Because clarithromycin-containing triple therapy and 10-day sequential therapy are now only effective in special populations, they are considered obsolete.”
  • The “preferred choices for Western countries” are the following
  1. 14-day concomitant therapy: PPI, amoxicillin 1 g, clarithromycin 500 mg, metronidazole -all twice daily
  2. 14-day bismuth quadruple therapy: PPI BID, bismuth BID, tetracycline 500 mg QID, metronidazole 500 mg TID
  3. 14-day hybrid sequential-concomitant therapy: 7 days of PPI-amoxicillin 1 g, followed by amoxicillin 1 g, clarithromycin 500 mg, metronidazole 500 mg for 7 days-all BID

Other useful points:

  • Tetracycline is not available in many parts of the world and generally doxycycline is not an adequate substitute for tetracycline.
  • Triple therapies are extremely sensitive to resistance of the third drug (eg. clarithromycin and metronidazole).  The increase in resistance is making these regimens ineffective
  • An online calculator can help predict which therapy to choose: https://hp-therapy.biomed.org/tw/ (need to know local resistance)
  • Poor compliance is the other factor besides resistance that can undermine a well-constructed treatment regimen. Spending ample time educating patients about the need to  take all of their medicines is crucial.
  • Figure 1 on page 178 outlines the recommended treatment approach.  Unfortunately, availability of susceptibility testing has been quite limited.

Take-home message: The authors emphasize using regimens that work locally and using the evidence that we have to choose the best treatments.  However, given the resistance patterns, working on collaborating with laboratories to culture HP for susceptibility/resistance would be worthwhile to increase the likelihood of excellent outcomes.

Related blog links:

Also noted:  full text article online (from Kipp Ellsworth twitter feed): http://goo.gl/dD2ooF “Intestinal Transplantation: An Unexpected Journey”  This is a succinct overview of intestinal transplantation’s progress and potential.

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Top Cited 100

Posted on by

In a recent commentary, the authors provide a list of the most commonly cited digestive disease articles from 1967-2007.  (Gastroenterol 2013; 144: 673-76)

The top three:

  1. Manns, M, et al. Lancet 2001; 358: 958-65. This study compared peginterferon alfa-2b with ribavirin against interferon with ribavirin for hepatitis C
  2. Fried M, et al. NEJM 2002; 347: 975-82. This study examined the use of peginterferon alfa-2a with ribavirin for hepatitis C
  3. Marshall B, Warren J. Lancet 1984; 1: 1311-15.  This study identified a bacteria (now called Helicobacter pylori) as a cause of ulcers and gastritis.

http://dx.doi.org/10.1053/j.gastro.2013.02.013

High Rates of Helicobacter Pylori Resistance

Posted on by

While the development of antibacterial resistance has broad implications, in gastroenterology patients specific problems have emerged with Helicobacter pylori (H pylori) and this has led to changes in first-line therapy( ).  More data on the treatment resistant H pylori has been published (JPGN 2013; 56: 645-48).

77 consecutive strains of H pylori  from Brazilian children and adolescents were isolated from gastric biopsies and analyzed; this study took place between 2008-2009 and the mean age was 11.1 years.  In 71 strains, there were no previous attempts at eradication.

Results:

  • 40% of strains were resistant to metronidazole
  • 19.5% of strains were resistant to clarithromycin
  • 10.4% of strains were resistant to amoxicillin
  • All strains were susceptible to furazolidone and tetracycline
  • 14/77 (18.2%) patients had multiple resistances

Take-home point: Resistance to antibiotics is altering our approach to H pylori therapy.  Antibiotic susceptibility testing may be needed to improve antibiotic selection and eradication rates.

Related blog links:

Helicobacter pylori –useful advice

Posted on by

Helicobacter pylori (H pylori) infections remain an important cause of gastritis, ulcers, and adenocarcinoma of the stomach.  One new approach in treatment has been the use of sequential therapy.  More data is now available on the effectiveness of this approach and choice of antibiotics (Gastroenterology 2012; 143: 55-61 & editorial 10-12).

In the study, a 10-day sequential regimen (SR) was compared with a 5-day concomitant regimen (CR).

  • CR group (n=90): esomeprazole 40 mg BID, amoxicillin 1 g BID, levofloxacin 500 mg BID, tinidazole 500 mg BID.  Eradication rate (intention-to-treat): 92%
  • SR group (n-90): esomeprazole 40 mg BID, amoxicillin 1 g BID for 5 days, then esomeprazole 40 mg BID, levofloxacin 500 mg BID, tinidazole 500 mg BID for 5 days. Eradication rate (intention-to-treat): 93%
  • Both groups had good results in part due to low resistance rates

Useful advice on this study from the editorial:

  • ‘We prefer concomitant therapy because it is not complex and it may retain its effectiveness at a slightly higher level of resistance compared with sequential therapy.”  Authors prefer 4-drug non-bismuth-containing concomitant treatment.
  • With bismuth therapy (eg. bismuth-metronidazole-tetracycline-PPI), authors prefer a 14 day course.  10-day treatment may be effective when metronidazole resistance is considered unlikely.
  • “Clarithromycin should be abandoned as an empiric regimen” due to resistance in U.S.
  • Fluoroquinolone resistance is increasing rapidly and “prior use virtually ensures resistance.”  Suggested use of fluoroquinolone therapy among adults would be as a rescue therapy (failed 2 different therapies), using dosing regimen as noted in cited study, and in patient without history of prior fluoroquinolone use (&/or proof on susceptibility testing)
What about treatment in kids?
In pediatrics, guidelines for treatment have been recently updated (JPGN 2011; 53: 230-43). (Benjamin Gold, MD -one of my partners is one of the authors and was the lead author of the first guidelines published in 2000.)  NASPGHAN guidelines. PDF of powerpoint slides: H. pylori infection in children: ESPGHAN/ NASPGHAN guidelines … & pdf of text: Evidence-based guidelines from ESPGHAN and NASPGHAN for …
Recommendations for first line treatment are a triple-based therapy with PPI and two antibiotics (eg. amoxicillin and metronidazole).  Alternatives, include bismuth plus two antibiotics, or sequential therapy.  Use of clarithromycin is recommended only after susceptibility testing.

Additional references:

  • -Gut 2010; 59: 1143-53.  Changing treatment recommendations for Helicobacter pylori in the face of resistance.
  • -Am J Gastroenterol 2007;  102: 1808-1825. American College of Gastroenterology Guideline on the Management of Helicobacter pylori Infection.  Doxycycline can be used in place of tetracycline
  • -Gastroenterol 2007; 133: 985. Review. Good article for resistant infections.
  • -Gastroenterol 2005; 129:1414-19.  Sequential Rx (amox + PPI x 5 days, then biaxin, tinidazole, PPI for 5 days) had 97% success.

HEROES trial

Posted on by

HEROES is definitely a catchy acronym (Arch Intern Med 2011; 171: 1929-36); HEROES is short for Helicobacter eradication relief of dyspeptic symptoms.

In pediatric practice, when Helicobacter pylori infection is identified, efforts are made to eradicate it.  However, studies have not been conclusive about whether this is beneficial for individuals with ‘functional dyspepsia.’  A 2006 Cochrane review of 21 trials found only 6 were positive for eradication.  Previous trials had not focused on primary care patients who may be more prone to respond.  As such, the investigators randomly assigned 404 patients (adults with average age of 46 years) into a group (n=201) treated with antibiotics and a control group (n=203); this was a randomized double-blind placebo-controlled clinical trial at a single center.  All eligible patients had to meet the Rome III criteria for functional dyspepsia and have H pylori infection.  Individuals with heartburn and irritable bowel were excluded. The antibiotic group received omeprazole, amoxicillin, and clarithromycin whereas the control group received omeprazole and placebo –both groups received treatment for 10 days.

In the antibiotic group, 49% achieved at least a 50% reduction in symptoms at 12 months; the control group had a 36.5% response.  Overall, 78.1% of the antibiotic cohort improved compared with 67.5% in the control cohort.

Although the findings of the study indicate improvement with a course of antibiotics, what to do with these results is not clear.  Worldwide, at least 50% of the population is infected by H pylori.  In addition, dyspeptic symptoms afflict up to 40% of the adult population in Western countries.  Due to the enormity of these problems, translating the results of this study into practical treatment strategies is difficult.

Additional references:

  • -JPGN 2011; 52: 387. Impact of Rome III criteria on yield. Still 2.8% w/o alarm symptoms that had significant endoscopic findings.
  • -Clin Gastro & Hep 2008; 6: 746. Antidepressant venlafaxine not effective in functional dyspepsia in double-blind, randomized, placebo-controlled study. n=160.
  • -Cochrane Database Syst Rev 2006; (2): CD002096. Rx of H pylori in functional dyspepsia.
  • -Gastroenterology 2007; 133: 799. Natural hx of functional disorders: 20% persist w same Sx, 40% develop other Sx, 40% get better. Large study from Olmstead county (n=1365)
  • -Gastroenterology 2007; 132: 1684.  Changes in cerebral blood flow during gastric balloon distention in dyspepsia.
  • -Gastroenterology 2006; 130: 1466-79. Functional gastroduodenal d/o. Acid suppression is 1st line Rx.
  • -Gastroenterology 2005; 129:1753-55, 1756-80, 1711. Mgt & guidelines for dyspepsia. In pts < 55 w/o alarm sx, test for H pylori and rx c PPI. In pts who don’t respond, consider EGD. Other Rx unclear: prokinetics, anticholinergics, antidepressants.
  • -Gastroenterology 2004; 127; 1239. Review of functional dyspepsia. Rx initial c acid-blocker/prokinetic reasonable, if not helpful, consider tricyclic, or clonidine. Eliminate H pylori. Sumatriptan may help
  • -J Pediatr 2005; 146: 448, 500.  Dyspepsia in children often associated with delayed GE and reduced gastric volumes
  • -Gastroenterology 2003; 125: 1219-26. Algorithm suggested:1. chech H pylori 2. Rx c PPI/H2RA.  3. If persists, EGD.  If EGD neg, consider elavil
  • -Clinical Gastro & Hepatology 2003; 1: 356. Increased Mast cells noted.
  • -Gastroenterology 2002; 123: 1778, 2132. Use of hypnosis for NUD.
  • -Ann Intern Med 2001; 134: 361-369. Meta-analysis of H pylori & NUD. Non-significant/minor improvement c eradication.