There are 3 point mutations, including A2143G, A2142G, and A2142C, that have been involved in Helicobacter pylori clarithromycin resistance.
Dr Vincenzo De Francesco and colleagues compared the eradication rates among the different point mutations.
The investigative team assessed the efficacy of triple therapy and a sequential regimen according to genotypic resistance.
The team conducted a post hoc subgroup study from a multicenter, randomized trial in 2 hospitals in Italy in 2001.
The investigators assessed 156 patients with H pylori infection.
Real-time polymerase chain reaction was used for assessing clarithromycin resistance.
|H pylori infection was eradicated in 48% with the A2143G mutation|
|Annals of Internal Medicine|
The team conducted histology, rapid urease test, and 13C-urea breath test at entry and after 4 to 6 weeks.
The team gave 7-day triple therapy consisting of 20 mg of rabeprazole, 500 mg of clarithromycin, and 1 g of amoxicillin to 75 patients.
A 10-day sequential regimen of 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 was given to 81 patients.
All drugs were given twice daily.
The investigators found that H pylori infection was eradicated in 48% of patients with the A2143G mutation.
H pylori was eradicated in 93% of patients with either A2142G or A2142C strains.
The team noted that the sequential regimen achieved a higher cure rate than triple therapy in A2143G mutate strains.
The investigators reported that the post hoc substudy design may require further confirmation.
Other limitations included the accessibility to the tool and the cost of investigations.
Dr De Francesco's team concluded, “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.“