Dual proton pump inhibitor plus amoxicillin as an empiric anti-H. pylori therapy: studies from the United States

Studies with CYP2C19 slow metabolizers have shown that the combination of a proton pump inhibitor (PPI) plus amoxicillin (dual therapy) can reliably cure more than 90% of Helicobacter pylori infections. Theoretically, the use of a PPI dose that provides equivalent acid suppression with fast metabolizers and slow metabolizers would achieve high cure rates irrespective of the CYP2C19 genotype. To evaluate high-dose PPI plus amoxicillin dual therapy for H. pylori eradication. H. pylori-infected individuals (positive by 2 tests) received esomeprazole 40 mg plus amoxicillin 750 mg every 8 h for 14 days. The protocol was planned based on the efficient identification strategy requiring more than 90% success, with stop criteria of 6 or more failures within 50 patients or a cure rate of less than 80%. Thirty-six patients (5 women, 31 men), average age 58 years, were enrolled before achieving stop criteria. All were first H. pylori treatments. The intention-to-treat cure was achieved in 26/36 [72.2%; 95% confidence interval (CI) = 56-84%] and in 26/35 per protocol (74.2%; 95% CI = 56-87%). There were no significant side effects. Compliance was 85% or greater in all (100% in 91.6%). If the hypothesis that consistently high intragastric pH is required to reliably achieve more than 90% H. pylori eradication, our regimen was not sufficient. Success may require more than every 8 h dosing, the concomitant administration of sodium bicarbonate, or the use of a long-acting PPI. However, the result was positive in that dual therapy with the doses tested here was at least as successful as empiric triple therapy.