Clarithromycin-based Therapy Research Articles

Metronidazole and clarithromycin resistance amongst Helicobacterpylori isolates from a large metropolitan hospital in the United States

Background: Metronidazole and clarithromycin-based therapies are among the most efficacious treatment regimens for H. pylori infection. Resistance to metronidazole or clarithromycin is associated with impaired therapy with these agents. We conducted a retrospective review of susceptibility data to determine the frequency of primary metronidazole and clarithromycin resistance among H. pylori isolates from a single metropolitan hospital in the United States. The database comprised 933 patients who presented at the Digestive Diseases Clinic at the Veterans Affairs Medical Center in Houston between September 1988 and January 1997 with complaints of dyspepsia, abdominal pain and peptic ulcer disease. One hundred and seventy-nine of these patients had both pharmaceutical records available for evaluation and culture and antimicrobial susceptibility data for analysis. The MICs were determined by both E-test and broth microdilution tests . The frequency of primary metronidazole resistance was 37.4% (67/179). The level of primary clarithromycin resistance was 6.1%. Dual metronidazole and clarithromycin resistance was present in approx. 3%. The high level of primary metronidazole and clarithromycin resistance in H. pylori isolates from this metropolitan hospital is such that antimicrobial susceptibility data should be available so that informed choice can be made for specific eradication therapies, especially in patients who fail treatment.

Assessment of a new triple agent regimen for the eradication of Helicobacter pylori and the nature of H. pylori resistance to this therapy in Japan.

Multiple regimens for the eradication of Helicobacter pylori have been tested, but the best therapy has not been determined yet. To determine the efficacy of a new triple agent regimen using a combination of lansoprazole, amoxicillin, and clarithromycin against Helicobacter pylori (H. pylori), and to examine H. pylori resistance to this therapy in ineffective cases. We studied a total of 71 patients infected with H. pylori who had gastric ulcer (n = 37) or duodenal ulcer (n = 34) as confirmed by endoscopy. Patients received 1500 mg amoxicillin, 400 mg clarithromycin and 30 mg lansoprazole for 2 weeks followed by 30 mg lansoprazole for 6 weeks in patients with gastric ulcer or for 4 weeks in those with duodenal ulcer. Endoscopic examination was performed before treatment and at 1 month, 2 months, and 5 months after initiating treatment to check the status of ulceration and H. pylori infection. The eradication rate of H. pylori was 92% (CI, 83-100%) in the gastric ulcer group and 94% (CI, 86-100%) in the duodenal ulcer group at 5 months, as determined by per-protocol analysis. Resistance to clarithromycin was present in 1 of 71 (1%) patients before treatment and in 2 of 5 (40%) patients after treatment. No resistance to amoxicillin and lansoprazole was found in patients before or after treatment. The resistance to clarithromycin changed during the observation period. The new triple agent regimen was effective against H. pylori. Resistance to clarithromycin may not be permanent and it might be one of the risk factors which affect the efficacy of a clarithromycin-based therapy.

Metronidazole, omeprazole and clarithromycin: an effective combination therapy for Helicobacter pylori infection

Successful treatment of Helicobacter pylori infection results in cure of peptic ulcer disease. Multi-drug regimens are needed to cure this infection. We studied the effectiveness and side effect profile of two antibiotics active against Helicobacter pylori, metronidazole and clarithromycin, combined with omeprazole. We evaluated a combination therapy for H. pylori infection consisting of metronidazole (500 mg b.d.), omeprazole (20 mg b.d.), and clarithromycin (250 mg b.d.) for 2 weeks, followed by ranitidine 300 mg daily for 4 weeks. Thirty-three patients with documented H. pylori infection were studied. Twenty had previously failed antimicrobial therapy, including one with metronidazole-based triple therapy and eight with macrolide-based therapy (five with clarithromycin-based therapy), and 11 with amoxycillin, tetracycline, and bismuth. H. pylori status was determined by histopathology using the Genta stain and by culture. H. pylori status was determined at entry and 4 weeks after completing antimicrobial therapy. The H. pylori infection was cured in 88% (95% CI = 72%-96%) including 90% of those who had failed previous anti-H. pylori therapies. Mild side effects were reported by 18%. We conclude that the combination of metronidazole, omeprazole and clarithromycin is an effective treatment for H. pylori infection.