Vonoprazan-based Eradication Therapy for H. Pylori Infection in Patients Allergic to Penicillin

Introduction: Vonoprazan (VPZ) is the first clinically available potassium competitive acid blocker (P-CAB), which can attain the more potent acid inhibition sooner in comparison with PPIs. Eradication of H. pylori in patients allergic to penicillin should be performed by the regimens without penicillin derivatives. We have used VPZ in the eradication therapy for H. pylori in patients allergic to penicillin. We report the retrospective results of the VPZ-based regimens for H. pylori infection in our hospital. Methods: From 2015 April to March 2016, a total of 39 patients infected with H. pylori and allergic to penicillin visited to our hospital. They underwent endoscopy. During endoscopy, gastric tissue samples were obtained and subjected to the culture test and further to the susceptibility test to clarithromycin (CAM), metronidazole (MNZ), minocycline (MINO) and sitafloxacin (STFX). Gastric tissue samples were also subjected to the genetic analysis of 23S rRNA of H. pylori at the positions of 2142 and 2143. Patients found to be infected with CAM-sensitive strains by the genetic test were treated with VPZ 20 mg bid, CAM 200 mg bid and MNZ 250 mg bid for 1 week. Others were treated with regimens based on culture test. Patients infected with strains sensitive to STFX and MNZ were treated with VPZ 20 mg bid, STFX 100 mg bid and MNZ 250 mg bid for 1 week. Those with strains sensitive to STFX, but resistant to MNZ were treated with VPZ 20 mg bid, STFX 100 mg bid and MINO 100 mg bid for 1 week. Success or failure of eradication was diagnosed based on 13C-Urea breath test. Results: The overall eradication rate was 89.7% (35/39). The eradication rate with the triple VPZ/CAM/MNZ therapy was 80.0% (7/9), that with the triple VPZ/STFX/MNZ therapy was 96.0% (24/25), and that with the triple VPZ/STFX/MNZ therapy was 75.0% (3/4). Mild adverse events such as loose stool were observed in 56.4% (22/39). No severe adverse events were observed. Conclusion: VPZ-based regimens with two of antimicrobial agents, such as CAM, MNZ, STFX and MINO for patients allergic to penicillin were effective and tolerable.