High-Dose Extended-Release Lansoprazole (Dexlansoprazole) and Amoxicillin Dual Therapy for Helicobacter pylori Infections

Background: Helicobacter pylori infections have become increasingly difficult to treat. Aim: To examine whether amoxicillin and high-dose dexlansoprazole would reliably achieve an H. pylori eradication rate of >= 90%. Methods: An open-label prospective pilot study of H. pylori eradication in treatment-naive subjects with active H. pylori infection (positive by two tests). Therapy: amoxicillin 1 g and dexlansoprazole 120 mg each twice a day at approximately 12-hour intervals for 14 days. Success was accessed by urea breath test. An effective therapy was defined as a per-protocol treatment success of 90% or greater; treatment success of 80% or less was prespecified as an unacceptable result. Results: After 13 subjects were entered (12 men, one woman; average age of 54 years), the prespecified stopping rule of six treatment failures was achieved (i.e., the 95% confidence interval excluded achieving the required 90% success rate even if the proposed study of 50 completed patients were entered) and enrollment was stopped. Per-protocol and intention-to-treat treatment success were both 53.8%; (7/13); 95% CI = 25-80%. Compliance was 100%. Three patients (23%) reported side effects, all of which were mild and none interrupted therapy. Conclusion: Theoretically, dual PPI plus amoxicillin should reliably eradicate H. pylori provided nearly neutral intragastric pH can be maintained. Clearly, dexlansoprazole, despite being administered at high dose and twice a day (i.e., total daily dose 240 mg), failed to achieve an intragastric milieu consistent with dual PPI plus amoxicillin therapy being an effective anti-H. pylori regimen.