One other study looking at the effect of pretreatment with PPI on eradication rates did not find a benefit . In addition to trials focussing on certain specific regimens, there were a number of studies that focussed on the processes of second- and third-line therapies over the last year. Regarding second-line therapy, one study from Japan revealed very high second-line eradication SCH772984 clinical trial rates with PPI, amoxicillin, and metronidazole for 1 week after failure of first-line eradication therapy with a PPI, amoxicillin, and clarithromycin and that the trend was stable over 5 years
with a reported overall second-line eradication rate of 92.4% . Another group reported a prospective study of patients with antibiotic resistance and found excellent eradication Alvelestat chemical structure rates of 88.6% in this population when culture-based selection for second-line therapy was employed . When treatment failure occurred, the interval between first-line H. pylori eradication treatment and second-line treatment may be critical to the second-line
therapeutic effect. A Japanese study reported an 88.6% ITT eradication rate for those treated with PPI, amoxicillin (1500 mg/day), and metronidazole (500 mg/day) for 1 week within 6 months of initial treatment failure compared with 68.8% when the second-line therapy was commenced after more than 180 days . On the issue of third-line therapy, a multicenter study also from Japan compared several options for rescue treatment and found triple therapy with PPI, amoxicillin, and sitafloxacin as the best option with 70% eradication and only 7.7% resistance . A very comprehensive review article this year suggested that in general clinical practice, levofloxacin–amoxicillin–PPI given twice daily, unless regional or new data show high quinolone resistance, is a good second-line combination . In one other study, doxycycline was seen to have no efficacy against H. pylori in a series of 16 patients with multiresistant strains when used Bcl-w with PPI and amoxicillin . There have been several studies again this year examining sequential and concomitant (non-bismuth quadruple) therapy, both in comparison with
standard triple therapy and each other. Sequential therapy consists of 5 days of PPI therapy plus amoxicillin, followed by a further 5 days of PPI with two other antibiotics, usually clarithromycin and metronidazole. By contrast, concomitant therapy involves maintaining three antibiotics along with the PPI for the duration of therapy. A very large and comprehensive meta-analysis and systematic review of studies looking at 5666 patients receiving sequential therapy compared with 7866 receiving other regimens concluded that the overall eradication rate of sequential therapy was suboptimal at 84.3% . It was, however, superior to 7-day triple therapy (risk ratio (RR) 1.21, number needed to treat (NNT) of 6), and marginally superior to 10-day triple therapy (RR 1.