Integrating the community pharmacist into the diabetes team: evaluation of a new care model for patients with Type 2 diabetes mellitus

Focal points

Failure of a 1-day high-dose quadruple therapy for cure of Helicobacter pylori infection

BACKGROUND

The optimal duration of treatment for eradication of Helicobacter pylori has still to be defined. A 1-day high-dose quadruple therapy with a combination of amoxycillin (or tetracycline), metronidazole, a bismuth salt and a proton pump inhibitor has led to eradication rates of 57-77%. In view of the high frequency of metronidazole-resistant strains of H. pylori in Europe, we hypothesized that by using clarithromycin in place of metronidazole and by increasing the dose of proton pump inhibitor, the efficacy of a 1-day high-dose quadruple therapy could be improved.

METHODS

Patients were randomized to receive either amoxycillin 1000 mg b.d., clarithromycin 500 mg b.d. and lansoprazole 30 mg b.d. for 7 days, or amoxycillin 2000 mg q.d.s., clarithromycin 500 mg q.d.s., lansoprazole 30 mg t.d.s. and bismuth subcitrate 240 mg q.d.s. for 1 day.

RESULTS

It was originally intended to include 100 patients. The first planned interim analysis performed after follow-up was completed for 30 patients revealed H. pylori eradication rates of 80% (12/15) in the 7-day triple therapy group and 20% (3/15) in the 1-day quadruple therapy group, the difference being highly significant (P = 0.003). Because the efficacy of the 1-day treatment was so low, the study was stopped for ethical reasons. Eleven patients who failed with the 1-day treatment were re-treated with the 7-day triple therapy: the eradication rate was 91% (10/11).

CONCLUSIONS

One-day high-dose quadruple therapy with amoxycillin, clarithromycin, lansoprazole and bismuth subcitrate is dramatically less effective than the classic 7-day triple therapy with the same antibiotics.

The eradication treatments of Helicobacter pylori

The eradication of Helicobacter pylori is at present widely recognized as the adequate therapeutic approach for gastric and duodenal ulcers in infected patients. In those with dyspepsia but no ulcer as well as in those with type B chronic gastritis, eradication remains controversial. It is difficult to have a clear opinion on the advantages and disadvantages of the numerous existing therapies. Therefore, a systematic review of published treatments has been made by the authors. Ideally, the eradication treatment of H. pylori should have the following advantages: 1. eradication superior to 90%, 2. simplicity, 3. short duration, 4. safety, 5. low cost, 6. reproducibility of results. Dual therapies (2 antibiotics or a proton pump inhibitor in combination with an antibiotic) rarely allow an eradication greater than 90% and the results have poor reproducibility. Consequently, they do not represent an ideal anti-H. pylori treatment. Triple therapies come closer to the requirements for an ideal treatment, with eradication rates generally close to 90%, varying little between studies and the countries in which they were performed. The triple therapy bismuth-imidazole-tetracycline (or amoxicillin) still represents for many authors the standard reference therapy. It has the advantage of low cost, high efficacy and widespread use. It is the therapy that has been the most studied. However, the increasing emergence of strains resistant to imidazoles, the complexity of the treatment (10 to 12 tablets per day), the numerous adverse effects and the lack of availability of bismuth salts in certain countries has led to the elaboration of therapeutic schemes combining an antisecretory drug with 2 antibiotics. Among these, the combination PPI-clarithromycine-imidazole during 7 days represents the most studied triple therapy of short duration for some authors, it already represents a new standard. However, the efficacy of this therapy seems dependent on the sensitivity of the bacteria to imidazoles. Consequently, this combination cannot be considered as the ideal anti-H. pylori treatment in the areas where the prevalence of strains resistant to imidazoles is high. The association PPI-clarithromycine-amoxicillin appears on the contrary to be very effective against strains resistant to metronidazole and therefore could constitute the treatment of choice in population with high prevalence of such strains. Great hope is currently surrounding the finalization of a vaccine directed against the urease of the bacteria. This approach would allow both the treatment and the prevention of Helicobacter pylori infection on a large scale.