Aim: To study different factors influencing the success of classic triple therapy in Helicobacter pylori eradication.
Methods: Fifty-seven duodenal ulcer patients infected with H. pylori were prospectively studied. At endoscopy biopsy specimens were taken from the gastric antrum and body (H & E, Gram stain, and culture). Classic triple therapy was administered (bismuth, tetracyclin, metronidazole). Patients were investigated endoscopically one month after completing therapy, and repeated biopsy specimens from the antrum and body were also obtained.
Results: H. pylori eradication was achieved in 42 patients (74%). In multiple logistic regression analysis metronidazole susceptibility (regr. coef. = 3.4; OR = 29.3) and previous therapy with omeprazol plus amoxycillin (regr. coef. = -1.7; OR = 0.18) were the only variables which correlated with success in H. pylori eradication (chi 2 model = 21; p < 0.001). Additional variables (age, sex, smoking, histologic lesion and ulcer history) were no correlated with H. pylori infection. H. pylori was susceptible to metronidazole in 36 patients (79%). Eradication rates for metronidazole-susceptible and metronidazole-resistant H. pylori isolates were 87% and 25%, respectively (p < 0.001). When previous therapy with omeprazole plus amoxycillin had been administered the eradication rate was lower (61%) than in patients without previous therapy (82%).
Conclusion: Success of classic triple therapy in H. pylori eradication is higher when the organism is metronidazole-susceptible, and lower when previous therapy with omeprazole plus amoxycillin has been administered. This factor, although not fully elucidated, lends no support to choosing triple therapy when eradicating therapy with omeprazole plus amoxycillin fails.