title: Triple therapy with high-dose proton-pump inhibitor, amoxicillin, and doxycycline is useless for Helicobacter pylori eradication: a proof-of-concept study.
abstract: BACKGROUND
  Helicobacter pylori resistance to antibiotics is steadily increasing and multidrug-resistant strains are common and difficult to eliminate, mainly in countries where bismuth, tetracycline, furazolidone, and rifabutin are unavailable.
  
  
  OBJECTIVE
  To evaluate the efficacy and safety of a triple therapy with proton-pump inhibitor (PPI), amoxicillin, and doxycycline in patients with multidrug-resistant H. pylori.
  
  
  METHODS
  This prospective study involved 16 patients (13 females; mean age - 50 ± 11.3 years) infected by H. pylori with known resistance to clarithromycin, metronidazole, and levofloxacin, but susceptibility to amoxicillin and tetracycline. All patients were previously submitted to upper endoscopy with gastric biopsies for H. pylori culture and susceptibility testing by Etest. Mutations in 23S rRNA and gyrA genes were determined by real-time PCR. A 10-day eradication regimen with PPI (double-standard dose b.i.d.), amoxicillin (1000 mg b.i.d.), and doxycycline (100 mg b.i.d.) was prescribed after pretreatment with PPI during 3 days. Eradication success was assessed by (13) C-urea breath test 6-10 weeks after treatment. Compliance and adverse events were determined through phone contact immediately after treatment and specific written questionnaires.
  
  
  RESULTS
  Only one patient did not complete treatment due to adverse events. Another four patients experienced mild side effects not affecting compliance. The control (13) C-urea breath test was positive in all patients. Per-protocol and intention-to-treat eradication rates were 0%.
  
  
  CONCLUSIONS
  Although safe, a triple-therapy protocol with high-dose PPI, amoxicillin, and doxycycline is useless for multidrug-resistant H. pylori eradication.
authors: Gastroenterology Department, Coimbra University Hospital, Coimbra, Portugal.
authors: Nuno
authors: N
authors: Almeida
authors: José M
authors: JM
authors: Romãozinho
authors: Maria M
authors: MM
authors: Donato
authors: Cristina
authors: C
authors: Luxo
authors: Olga
authors: O
authors: Cardoso
authors: Maria A
authors: MA
authors: Cipriano
authors: Carol
authors: C
authors: Marinho
authors: Carlos
authors: C
authors: Sofia
mesh_terms: D000328:Adult; D000368:Aged; D000658:Amoxicillin / Q000009:adverse effects / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001944:Breath Tests; D017291:Clarithromycin / Q000494:pharmacology; D027081:DNA Gyrase / Q000235:genetics; D060740:Disease Eradication / Q000379:methods; D004318:Doxycycline / Q000009:adverse effects / Q000627:therapeutic use*; D024901:Drug Resistance, Multiple, Bacterial; D004359:Drug Therapy, Combination / Q000009:adverse effects / Q000379:methods; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects / Q000235:genetics; D006801:Humans; D064704:Levofloxacin / Q000494:pharmacology; D008297:Male; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009154:Mutation; D011446:Prospective Studies; D054328:Proton Pump Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D017211:Treatment Failure
chemical_list: D000900:Anti-Bacterial Agents; D054328:Proton Pump Inhibitors; D012338:RNA, Ribosomal, 23S; D008795:Metronidazole; D064704:Levofloxacin; D000658:Amoxicillin; D027081:DNA Gyrase; D017291:Clarithromycin; D004318:Doxycycline
keywords: Helicobacter pylori; antibiotics; doxycycline; multidrug resistant; susceptibility testing