Therapy of H. pylori infection.

A simple, safe and effective 1 week low dose triple therapy, omeprazole 20 mg u.i.d. clarithromycin 250 b.i.d. tinidazole 500 mg b.i.d. (OCT) was developed in response to the problems seen with standard triple and dual therapies. Standard triple therapy, bismuth and two antibiotics, in fact, is effective for the eradication of H. pylori but is of limited use, because of side effects and the patients low compliance. The combination of omeprazole plus one antibiotic, either amoxycillin or clarithromycin, has resulted in various rates of eradication in different geographical areas, most of them being inconsistent and low. The short term low dose triple therapy was therefore based on the rationale that measures aiming at reducing side effects and improving patient compliance with an appropriate combination of drugs would lead to a substantial improvement in the eradication rate. This regimen initially tested in H. pylori +ve patients with gastritis, is highly effective (> 90%) for long term eradication also in duodenal ulcer patients and in patients with gastric ulcer. Consistent results have been reproduced by several investigators with the same regime, whilst increasing dosages and duration of treatment does not seem to improve success rate. In alternative, omeprazole, clarithromycin, amoxicillin (OCA) has been also suggested to overcome the problem of metronidazole resistance, however recent studies seem to indicate that resistance to metronidazole does not seem to significantly influence outcome of OCT. In conclusion, also according to the recent Maastricht Consensus Report, the short term low dose triple therapy consisting of a PPI plus antibiotics--any two among clarithromycin, tinidazole/metronidazole and amoxycillin--currently represent the most effective approach to H. pylori eradication.