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'Upset Stomach' Feels Better After Killing H. pylori

Ƶ MedicalToday

Eradicating Helicobacter pylori with antibiotics provided significant benefits to primary care patients with functional dyspepsia, randomized trial results showed.

Nearly half (49%) of the patients who took antibiotics saw symptom improvement of at least 50% compared with just 36.5% in the control group who had that much improvement, according to Luiz Edmundo Mazzoleni, MD, PhD, from the Hospital de Clinicas de Porto Alegre in Brazil, and colleagues.

That made for an absolute difference between groups of 12.5% (95% CI 2.1 to 22.7, P=0.01), they reported in the Nov. 28 issue of Archives of Internal Medicine.

Action Points

  • In this study, therapy designed to eradicate Helicobacter pylori provided significant benefits to a proportion of patients with functional dyspepsia.
  • Note that the mechanism of action remains unclear, and it is not certain that eradication of H. pylori is the sole explanation for relief of functional dyspepsia.

One of the underlying mechanisms of functional dyspepsia is H. pylori infection, and at least 50% of the world's population is infected by the bacterium, the authors explained.

Previous studies that looked at H. pylori eradication in this patient population has yielded conflicting results, and official assessment guidelines are at odds: The American College of Gastroenterology states that testing for H.pylori in these patients remains controversial while the Maastricht III Consensus Report recommends testing.

The HEROES (Helicobacter Eradication Relief of Dyspeptic Symptoms) trial was randomized, placebo-controlled, and conducted at a single academic hospital. Patients with a diagnosis of H.pylori infection and functional dyspepsia were enrolled and assigned to one of two treatment groups:

  • Those in the antibiotics group received 20 mg twice daily of omeprazole, 1,000 mg twice daily of amoxicillin trihydrate, and 500 mg twice daily of clarithromycin for 10 days.
  • Those in the control group received 20 mg twice daily of omeprazole and placebo antibiotics for 10 days.

Patients were randomized at baseline and returned for follow-up visits at four, eight, and 12 months. Upper GI endoscopies were performed at screening and at the end of follow-up.

The primary endpoint was the proportion of patients with at least a 50% decrease in dyspeptic symptoms score at 12 months compared with the baseline score. The authors also looked at changes in quality of life.

All analyses were performed by intention to treat, and the number needed to treat to achieve the primary endpoint was eight.

Between 2006 and 2008, 407 patients were randomized into the study with 201 in the antibiotics group and 203 in the control group. A little more than 96% of the the patients completed the study.

In the antibiotics group, 78.1% reported improvement in global assessment of symptoms compared with 67.5% in the control group (P=0.02).

The mean decrease in symptom score was -10.47 in the study arm and -7.76 in the control arm (P=0.008).

There was no significant difference between the groups in the rate of complete resolution of symptoms.

In terms of quality of life, those in the antibiotics group reported significant improvement in scores (4.15) compared with controls (2.20) for physical changes (P=0.02) but there was no difference for mental changes (1.29 versus 2.9, P=0.18).

According to the intention-to-treat analysis and after one year, 88.6% of those in the antibiotics arm were negative for H. pylori compared with 7.4% in the control arm (P<0.001).

In the final, stepwise logistic regression analysis model, the authors found two predictors of symptomatic improvements -- antibiotics (OR 1.63, P=0.01) and recent dyspepsia (OR 1.51, P=0.048).

Serious adverse events did not crop up in either group until 30 days after completing treatment; 3.5% of patients developed peptic ulcers. Other adverse events included abnormal taste, diarrhea, and malaise.

The authors acknowledged that the study's applicability may be limited because it was conducted at a single center. However, they stressed, a major strength of the trial was the definition of the primary endpoint, the authors stressed.

"In this study, 93.4% of the patients who experienced the primary endpoint reported improvement in patient global assessment of symptoms, suggesting that 50% symptom improvement is a clinically relevant cutoff," they wrote.

H. pylori eradication offers the advantage of being a short-term treatment that isn't restricted to any dyspepsia subtype, they explained.

Additionally, improvements in quality of life should "contribute to the adaptation of economic models of H. pylori eradication to primary care populations."

In fact, the cost of diagnosing and treating functional dyspepsia comes in at about $1 billion a year in the U.S., wrote Paul Moayyedi, MBChB, PhD, from McMaster University in Hamilton, Ontario, in an accompanying commentary.

He praised the HEROES trial for being well done with a low risk of bias. However, future studies need to go a step further, he wrote, to determine the mechanism of action for H. pylori eradication in reducing functional dyspepsia symptoms.

"It is possible that the antibiotics used in H. pylori eradication therapy are treating other organisms rather than H. pylori, and this is the reason for their effect in functional dyspepsia," Moayyedi pointed out. "The challenge will be to establish the mechanism underlying this effect so that we can ... better treat our patients with this common and costly condition."

Disclosures

The drugs used in this study and a gastroscope were donated by Aché Laboratórios Farmacéuticos SA.

The authors reported no relevant financial disclosures.

Moayyedi has received speakers' fees and research funds from, as well as served on advisory boards for, AstraZeneca, Abbott, Nycomed, Johnson & Johnson, and Takeda.

Primary Source

Archives of Internal Medicine

Mazzoleni LE, et al "Helicobacter pylori eradication in functional dyspepsia -- HEROES Trial" Arch Intern Med 2011; 171(21): 1929-1936.

Secondary Source

Archives of Internal Medicine

Moayyedi P "Helicobacter pylori Eradication for functional dyspepsia -- What are we treating?" Arch Intern Med 2011; 171(21): 1936-1939.