Prevention of Duodenal Ulcer Recurrence with Penicillin

Abstract

The relationship between Helicobacter pylori and duodenal ulcer has been interpreted as causal, but existing evidence has been criticized for methodologic reasons. We conducted a randomized trial of phenoxymethylpenicillin, 2.4 g twice daily, and placebo to determine whether an antibiotic, which has no effect on the integrity of the epithelial cells, prevents recurrence of duodenal ulcer. Patients with an active duodenal ulcer and positive H. pylori culture, assessed from antral biopsy specimens, were treated with omeprazole, 40 mg once daily, for a total of 4 weeks. After 2 weeks' treatment with omeprazole, these patients were randomized to receive phenoxymethylpenicillin (n = 85) or placebo (n = 85). In patients whose ulcer had healed after 4 weeks' omeprazole therapy, phenoxymethylpenicillin or placebo was continued for an additional 12 weeks. Patients without ulcer recurrence during this treatment period were followed up for a further 6 months. Endoscopy was performed and H. pylori culture assessed at the end of the first treatment period (14 weeks), at the end of the follow-up period (a further 6 months), and immediately if ulcer symptoms recurred. Five out of 58 (9%) patients receiving phenoxymethylpenicillin had duodenal ulcer recurrence during the treatment period, compared with 34 out of 68 (50%) patients taking placebo (p < 0.0001; log-rank test) (Fig. 1).

The ulcer recurrence rate in the phenoxymethylpenicillin-treated group remained low for another 5 months after penicillin treatment but approached the rate seen in the placebo group during the sixth month of the follow-up period. The prevalence of H. pv/on'-positive patients after 14 weeks of penicillin administration and at the end of the follow-up period was 47% and 80%, respectively, compared with 86% and 90%, respectively, in the placebo group. These data provide strong evidence that duodenal ulcer has an underlying bacterial component, with H. pylori being the likely cause. Pronounced inhibition of H. pylori growth was obtained with omeprazole alone. This inhibition was increased by the addition of phenoxymethylpenicillin, but eradication was generally not obtained.

Key Words:

• Duodenal ulcer
• Helicobacter pylori
• omeprazole
• penicillin