Helicobactor Pylori

Helicobactor pylori is a gram negative bacillus uniquely adapted to survival in the hostile environment of stomach. They attaches to the surface epithelium beneth of the mucus, has high urease activity- produce ammonia, which maintains a neutral microenvironment to bacteria and promotes back diffusion of H+ ions.

H. pylori infection starts with a neutrophilic gastritis lasting 7-10 days, which is usually asymptomatic. Once established, H. pylori generally persists for the life of the host, upto 90% patients of duodenal and gastric ulcer, have tested positive for H. pylori.

Anti-helicobactor pylori

Anti- microbials that have been found clinically effective against H. pylori are: Amoxycillin, Clarithromycin, tetracycline and metronidazole. However, any single drugs is relatively ineffective. Resistance develops rapidly.

Dose:

One week regimens

1. Amoxycillin 500mg TDS/Clarithromycin 250mg BD +metronidazole 400mg TDS+Omeprazole 20mg BD
2. Amoxycillin 500mg TDS+Clarithromycin 250mg TDS + Omeprazole 20mg BD.

Two week regimens

1. Clarithromycin 500mg TDS/Amoxycillin 750 mg BD+ Omeprazole 20mg BD
2. Amoxycillin 500mg TDS/Tetracycline 500mg QID+ Metronidazole 400mg QID+Bismuth 120mg QID.
3. Amoxycillin 750mg TDS+ metronidazole 500mg TDS + Ranitidine 300mg OD.

The regimens are complex and expensive, compliance is poor and side effects are frequent. A comparative examination of all the literature between 1990-1995 relating to H. pylori therapy has suggested that triple therapy that is :

Omeprazole 20 mg + Clarithromycin 500mg + Tinidazole 1000mg per, day for 7 days has high eradication rate (>90%), less side effect( 7%) and required less number of total tablets. However, Amoxycillin can be substituted for clarithromycin with similar benefits.