title: Clarithromycin-resistant genotypes and eradication of Helicobacter pylori.
abstract: BACKGROUND
  Three point mutations (A2143G, A2142G, and A2142C) have been involved in Helicobacter pylori clarithromycin resistance.
  
  
  OBJECTIVE
  To compare the eradication rates among the different point mutations and the efficacy of triple therapy and a sequential regimen according to genotypic resistance.
  
  
  METHODS
  Post hoc subgroup study from a multicenter, randomized trial.
  
  
  METHODS
  Two hospitals in central and southern Italy between January and December 2001.
  
  
  METHODS
  156 patients with H. pylori infection.
  
  
  METHODS
  Real-time polymerase chain reaction for assessing clarithromycin resistance; histology, rapid urease test, and 13C-urea breath test at entry and after 4 to 6 weeks.
  
  
  METHODS
  7-day triple therapy (20 mg of rabeprazole, 500 mg of clarithromycin, and 1 g of amoxicillin) in 75 patients or a 10-day sequential regimen (20 mg of rabeprazole plus 1 g of amoxicillin for 5 days and 20 mg of rabeprazole, 500 mg of clarithromycin, and 500 mg of tinidazole for the remaining 5 days) in 81 patients. All drugs were given twice daily.
  
  
  RESULTS
  Helicobacter pylori infection was eradicated in 11 of 23 patients (48%) with the A2143G mutation and in 14 of 15 patients (93%) with either A2142G or A2142C strains (difference, 45 percentage points [95% CI, 15 to 65 percentage points]; P = 0.004). The sequential regimen achieved a higher cure rate than triple therapy in A2143G mutate strains (difference, 49 percentage points [CI, 8 to 72 percentage points]; P = 0.024).
  
  
  CONCLUSIONS
  The post hoc substudy design may require further confirmation. Other limitations are the accessibility to the tool and the cost of investigations (70 euros per patient).
  
  
  CONCLUSIONS
  The A2143G mutation seemed to be associated with a very low eradication rate. The sequential regimen achieved a higher cure rate than standard therapy even in patients with these strains.
authors.affiliation: Ospedali Riuniti and University of Foggia, Foggia, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: De Francesco
authors.forename: Marcella
authors.initials: M
authors.lastname: Margiotta
authors.forename: Angelo
authors.initials: A
authors.lastname: Zullo
authors.forename: Cesare
authors.initials: C
authors.lastname: Hassan
authors.forename: Laura
authors.initials: L
authors.lastname: Troiani
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Burattini
authors.forename: Francesca
authors.initials: F
authors.lastname: Stella
authors.forename: Alfredo
authors.initials: A
authors.lastname: Di Leo
authors.forename: Francesco
authors.initials: F
authors.lastname: Russo
authors.forename: Stefania
authors.initials: S
authors.lastname: Marangi
authors.forename: Rosa
authors.initials: R
authors.lastname: Monno
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Stoppino
authors.forename: Sergio
authors.initials: S
authors.lastname: Morini
authors.forename: Carmine
authors.initials: C
authors.lastname: Panella
authors.forename: Enzo
authors.initials: E
authors.lastname: Ierardi
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000658:Amoxicillin / Q000008:administration & dosage*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D001562:Benzimidazoles / Q000008:administration & dosage*; D017291:Clarithromycin / Q000008:administration & dosage*; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination; D005838:Genotype; D016481:Helicobacter Infections / Q000188:drug therapy* / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000235:genetics*; D006801:Humans; D009853:Omeprazole / Q000008:administration & dosage / Q000031:analogs & derivatives*; D017354:Point Mutation; D064750:Rabeprazole; D016896:Treatment Outcome
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000900:Anti-Bacterial Agents; D001562:Benzimidazoles; D064750:Rabeprazole; D000658:Amoxicillin; D017291:Clarithromycin; D009853:Omeprazole