Lower H. Pylori Eradication Rates With Prior Exposure to Macrolide Antibiotics

By Will Boggs MD

June 04, 2019

NEW YORK (Reuters Health) - Patients with previous exposure to macrolide antibiotics have lower Helicobacter pylori eradication rates with clarithromycin-based triple therapy, according to a retrospective study.

American College of Gastroenterology guidelines recommend avoiding clarithromycin-based triple therapy for patients with past macrolide exposure, but is ambiguous regarding the use of quadruple therapy in this setting. Data to support the recommendation are scarce.

Dr. Doron Boltin and colleagues from Rabin Medical Center, in Petah Tikva, and the Sackler School of Medicine at Tel Aviv University, in Israel, used data from the Clalit Health Services database to investigate the impact of previous macrolide exposure on the outcomes of triple and quadruple treatment protocols for H. pylori infection in their region.

Among the 7,842 patients included in the study, 39.0% had previous exposure to macrolide antibiotics and 78.9% had successful eradication of H. pylori.

Most patients received clarithromycin-based triple therapy (88.1%, with 79.4% eradication), 5.6% received sequential quadruple therapy (82.7% eradication), 1.6% received concomitant quadruple therapy (81.3% eradication), and 4.7% received triple therapy with proton-pump inhibitor, clarithromycin and a nitroimidazole (65.6% eradication).

Overall, macrolide exposure was associated with a decrease in the success of H. pylori eradication from 82.4% to 73.4%, a 41% drop in the odds of eradication (P<0.001), the researchers report in The American Journal of Gastroenterology, online April 25.

The odds of eradication were 68% lower with previous exposure to clarithromycin, 38% lower with roxythromycin and 40% lower with erythromycin, but not significantly lower with azithromycin.

Previous exposure to clarithromycin, roxythromycin and erythromycin were linked to significantly decreased success of both clarithromycin-based regimens, but not the success of sequential or concomitant quadruple therapy.

In multivariable analysis, previous macrolide exposure was associated with 79% higher odds of eradication failure (P<0.0001). Age and Charlson Comorbidity Index were other independent factors associated with treatment outcome.

The odds of successful eradication increased along with the time between macrolide exposure and H. pylori treatment and decreased with increasing cumulative macrolide dose and with increasing number of prior macrolide exposures.

"Clinicians should enquire about previous macrolide use and search electronic medical records before making a clinical decision on the treatment of H. pylori infection," the researchers conclude. "In the absence of resistance testing, sequential, concomitant, and bismuth-based treatment may be the preferred options for the treatment of H. pylori infection among patients with previous exposure to macrolide antibiotics."

Dr. Sheila E. Crowe of the University of California, San Diego, in La Jolla, who recently reviewed the diagnosis and treatment of H. pylori infection, told Reuters Health by email, "The authors concluded that clarithromycin-based triple therapy is adversely affected by previous exposure to macrolides. I agree with the authors that sequential, concomitant, and bismuth-based treatments may be preferred in those settings."

"I am somewhat surprised that the prior use of macrolides did not create a larger effect on current macrolide treatments," she said. "I would be interested to see if a similar result would occur in other parts of the world."

Dr. Boltin did not respond to a request for comments.

SOURCE: https://bit.ly/30WWX0o

Am J Gastroenterol 2019.