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Helicobacter pylori-associated Peptic Ulcers

Infection with H. pylori ( a spiral-shaped bacterium) is a necessary cofactor for the overwhelming majority of duodenal and gastric ulcers not associated with NSAIDs; more than 90% of patients with duodenal ulcer have H. pylori chronic gastritis.

After standard therapy with H2-antagonists or sucralfate, 70% to 85% of affected patients per year have a recurrence. One half of these are asymptomatic.

Patients with active ulcers should have antral biopsies taken at endoscopy. If histologic examination shows normal mucosa, NSAIDs or hypersecretory states are more likely possibilities than H. pylori infection. However, because approximately one half of patients taking chronic NSAID therapy who develop ulcers also have chronic H. pylori gastritis, the cause of the ulcer may be unclear.

DX of H. pylori:

• Serum H. pylori IgG serology (80 - 90% sensitivity & specificity)
  - positive in serum about 21 days after infection & can remain present long after the organism is eradicated.
  - the main disadvantage is that it cannot distinguish between active infection & previous exposure to H pylori.
• Breath Urea test with 13C or 14C labeled urea to drink. (94 - 98% sensitivity & specificity)
  - detects active H pylori infection & is highly accurate.
• Stool antigen test (93% sensitivity & specificity)
  - detects active H pylori infection & is highly accurate.
• Stomach or duodenal mucosa biopsy urease test or histologic identification of organisms or culture of biopsy.

THERAPY FOR HELICOBACTER PYLORI:

§ The ONE WEEK  3-drug regimen is recommended as first-line therapy for eradication of H.pylori in patients who test positive:

1. Amoxicillin 1 gm BID , or Metronidazole (Flagyl) 500 mg BID plus
2. Clarithromycin (Biaxin) 500 mg BID, plus
3. Pantoprazole (Protonix) 40 mg BID or Omeprazole (Prilosec) 20 mg  BID

The 10-day regimen with

• Omeprazole (Prilosec) 20 mg  BID or Lansoprazole 30 mg bid
• Clarithromycin (Biaxin) 500 mg BID
• Metronidazole (Flagyl) 500 mg BID or Amoxicillin 1 gm bid
  has 87-91% cure.

The regimen a 14-day regimen of

• Pepto-bismuth/ BSS, 2 tablets four times a day;
• metronidazole, 250 mg four times a day; and
• tetracycline, 500 mg four times a day
• H2 receptor antagonist as Cimetidine or Ranitidine x 4 weeks
  eradicates the organism in >85% of treated patients.
  Failure of triple therapy is usually the result of noncompliance or metronidazole resistance.
  Side effects including nausea, vomiting, and diarrhea occur in up to one third of patients given triple therapy, potentially limiting patient tolerance and compliance. Nevertheless, triple therapy remains the gold standard for eradication.

Other FDA-approved Rx options (as of July 1998):

• Omeprazole 40 mg QD + Clarithromycin 500 mg tid x 2 wks, then Omeprazole 20 mg QD x 2 wks.
• Lansoprazole 30 mg bid + Clarithromycin 500 mg tid + Amoxicillin 1 gm BID x 10 days
• Ranitidin bismuth citrate (RBC) 400 mg bid + Clarithromycin 500 mg bid or tid x 2 wks, then RBC 400 mg bid x 2 wks.

REF:
ACP Library on Disk 2- (c) 1997 - American College of Physicians   
Cleveland Clinic J of Med  Supplent 2 to Vol 72, May 2005

CDC Fact Sheet on H.Pylori       

Surgery to Cure the Zollinger-Ellison Syndrome NEJM 8-26-1999  
                                                                     
                                                         

06022005

The Stool Antigen Test for Detection of Helicobacter pylori after Eradication Therapy
Ann Intern Med. Feb. 19, 2002;136:280-287  
A positive result on the stool antigen test 7 days after completion of therapy identifies patients in whom eradication of H. pylori was unsuccessful.