Omeprazole, amoxicillin and bismuth for peptic ulcer healing and Helicobacter pylori eradication

A controlled, randomized study was performed in patients with active peptic ulcer disease and positive Helicobacter pylori (Hp) status to assess the clinical efficacy (endoscopic healing and eradication of Hp) of different combined treatments. In the first part of the study a treatment with omeprazole (CAS 73590-58-6) (40 mg once daily) alone (group A) or in combination with tripotassium dicitrato bismuthate (TDB; 240 mg bid, group B) for 4 weeks was evaluated in 20 and 13 patients, respectively. As expected healing rates were high and comparable (75 vs. 85%), however, Hp-eradication was zero in both groups. In the subsequent second part of the trial group A (n = 19) received omeprazole (20 mg bid) for 2 weeks + amoxicillin (CAS 26787-78-0) tablets (1 g bid only 2nd week). Accumulated healing rate increased to 95% but Hp-eradication was 37%. From group B only 8 patients participated in a second 4-week course of monotherapy with TDB. Whereas healing occurred in all individuals, Hp-eradication was still low (12.5%). In addition plasma levels (omeprazole, Bi) and urinary excretion (Bi) were monitored to test whether drug interaction and/or noncompliance of the patients could help to explain the clinical findings. Systemic availability of Bi was increased by the coadministration of omeprazole and plasma levels of omeprazole were in general higher in Hp-positive patients if compared to those of Hp-negative patients. The following conclusions could be drawn from the 4 parts of the study: Treatment of peptic ulcer disease with omeprazole either alone or in combination with TDB is effective for ulcer healing but not for eradicating Hp. Omeprazole seems to decrease the Hp-eradicating potential of Bi probably due to a drug interaction. A second treatment course with TDB is apparently not of much benefit. One week pretreatment with omeprazole does not affect healing but might attenuate Hp-eradication rate of subsequent combined treatment with amoxicillin. One week coadministration of amoxicillin is not sufficient. The magnitude of omeprazole's plasma levels has no effect on Hp-eradication rates. As the numbers of patients in this study was relatively small these conclusions need to be confirmed by larger trials.