Helicobacter pylori Infection
H. pylori–associated ulcers often heal spontaneously but frequently recur. Treatment for 14 days ( Table 142-3 ) has about a 10% advantage over 7-day eradication therapy.[1] Seven-day treatment may be acceptable in regions where local studies have shown that a particular treatment is very effective and is probably the most economical option in countries with low health care costs. After 4 weeks of acid suppressive therapy, more than 80% of ulcers will heal, and this number increases to more than 90% after 8 weeks of therapy. For patients in whom such therapy fails, a 4- to 10-day course of quadruple therapy is advised. This second-line regimen enables eradication of H. pylori in an additional 80 to 90% of patients. Resistance of H. pylori to metronidazole varies between 10 and 80% throughout the world.Clarithromycin resistance is increasing and is now estimated to be at 5 to 10% in the United States because of widespread use of macrolides as therapy for upper respiratory infections. Resistance to amoxicillin and to tetracycline is rare and is not usually relevant in clinical practice. Sequential therapy may be superior to standard triple therapy.[2] Continuation of acid suppressive therapy after antibiotic treatment is needed only when symptoms persist and before eradication of H. pylori has been confirmed. The subsequent decrease or disappearance of ulcer symptoms is a useful indicator of successful H. pylori eradication. Testing to ascertain H. pylori status after therapy is indicated in patients with prior complicated ulcer disease or with persistent or recurrent symptoms after therapy, as well as in patients who fail to complete the therapeutic course. When H. pylori persists, ulcers recur in 50 to 90% of patients within 12 to 24 months. This rate can be reduced to 20 to 30% with maintenance acid suppression. Ascertainment of therapeutic efficacy must be delayed until at least 1 month after the end of treatment to prevent false-negative results related to the temporary suppression but not eradication of the organism. When repeat endoscopy is needed (e.g., a gastric ulcer that requires repeated histologic examination to exclude underlying malignancy), repeat screening for H. pylori can be performed using the gastric biopsy specimens for histologic examination, culture, or urease testing. If no clinical indication exists for repeat endoscopy, then H. pylori status can be determined by means of a 13C-urea breath test, stool H. pylori antigen, or repeated serology. Serologic determination is based on a more than 40 to 50% decrease in immunoglobulin G antibody levels in the first 6 months after treatment compared with pretreatment in that patient.
TABLE 142-3 -- OVERVIEW OF ANTIBIOTICS USED FOR H. PYLORI ERADICATION
Drug Class Drug Triple Therapy[*] Quadruple Therapy[†]
Acid suppression Proton pump inhibitor 20–40 mg bid[‡] 20–40 mg bid[‡]
Standard antimicrobials Bismuth compound[§] 2 tablets bid 2 tablets bid
Amoxicillin 1 g bid —
Metronidazole[ ] 500 mg bid 500 mg tid
Clarithromycin 500 mg bid —
Tetracycline 500 mg qid
Salvage antimicrobials Levofloxacin 300 mg bid —
Rifabutin 150 mg bid —
Furazolidone 100 mg bid —
* Triple therapy consists of a proton pump inhibitor or bismuth compound, together with two of the listed antibiotics, usually given for 7 to 14 days.
† Quadruple therapy consists of a proton pump inhibitor plus a bismuth compound with two antibiotics as listed given for 4 to 10 days.
‡ Proton pump inhibitor dose equivalent to omeprazole 20 mg bid.
§ Bismuth subsalicylate or subcitrate.
Alternative = tinidazole, 500 mg bid. bid = twice daily; tid = three times daily.
CONCLUSION: Levofloxacina se indica en casos de resistencia a una triple terapia de tratamiento corto, y se reemplaza a la Claritromicina, ya que es el que mas resistencia tiene debido a su uso (indiscriminado?) en infecciones de VAS.
Fuente: Cecil 23 edition
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