Helicobacter Pylori (cont.)

H. pylori is difficult to eradicate from the stomach because it is capable of developing resistance to commonly used antibiotics. Therefore, two or more antibiotics usually are given together with a PPI and/or bismuth containing compounds to eradicate the bacterium. (Bismuth and PPIs have anti-H. pylori effects.) Examples of combinations of medications that are effective are:

• a PPI, amoxicillin (Amoxil) and clarithromycin (Biaxin)
• a PPI, metronidazole (Flagyl), tetracycline and bismuth subsalicylate (Pepto-Bismol, Bismuth)

These combinations of medications can be expected to cure 70% to 90% of infections. However, studies have shown that resistance of H. pylori (failure of antibiotics to eradicate the bacterium) to clarithromycin is common among patients who have prior exposure to clarithromycin or other chemically similar macrolide antibiotics (such as erythromycin). Similarly, H. pylori resistance to metronidazole is common among patients who have had prior exposure to metronidazole. In these patients, doctors have to find other combinations of antibiotics to treat the H. pylori. Antibiotic resistance is another reason why antibiotics should be used carefully and judiciously for the right reasons, and indiscriminate use of antibiotics for improper reasons should be discouraged. First-line regimens for Helicobacter pylori eradication are taken from the guidelines developed by the American College of Gastroenterology as follows:

1. Standard dose of a *PPI (proton pump inhibitor) *b.i.d. (esomeprazole is *q.d.), clarithromycin 500 mg b.i.d., amoxicillin 1,000 mg b.i.d. for 10-14 days
2. Standard dose PPI b.i.d., clarithromycin 500 mg b.i.d. metronidazole 500 mg b.i.d. for 10-14 days
3. Bismuth subsalicylate 525 mg p.o. q.i.d. metronidazole 250 mg * p.o. *q.i.d., tetracycline 500 mg p.o. q.i.d., ranitidine 150 mg p.o. b.i.d. or standard dose PPI q.d. to b.i.d. for 10-14 days
4. PPI + amoxicillin 1 g b.i.d., for 5 days, followed by PPI, clarithromycin 500 mg, tinidazole 500 mg b.i.d. for 5 days (used mainly in other countries)

*PPI = proton pump inhibitor; pcn = penicillin; p.o. = orally; q.d. = daily; b.i.d. = twice daily; t.i.d. = three times daily; q.i.d. = four times daily.

Some doctors may want to confirm eradication of H. pylori after treatment with a urea breath test or a stool antigen test, particularly if there have been serious complications of the infection such as perforation or bleeding in the stomach or duodenum. Endoscopic biopsies to determine eradication of the bacterium are not necessary, and blood tests are not good for determining eradication since it takes many months for the antibodies to H. pylori to decrease. The best tests for determining eradication are the breath and stool tests discussed previously. Patients who fail to eradicate H. pylori with treatment are retreated, often with a different combination of medications.

Source: MedicineNet.com
http://www.medicinenet.com/helicobacter_pylori/article.htm