First-Line <i>Helicobacter pylori</i> Eradication with Vonoprazan, Clarithromycin, and Metronidazole in Patients Allergic to Penicillin

<jats:p><jats:italic>Aim</jats:italic>. To assess the efficacy of 7-day first-line <jats:italic>Helicobacter pylori</jats:italic> eradication with vonoprazan (VPZ), clarithromycin (CAM), and metronidazole (MNZ) in patients with penicillin allergy. <jats:italic>Methods</jats:italic>. Patients with penicillin allergy, diagnosed with <jats:italic>Helicobacter pylori</jats:italic> infection and did not have history of <jats:italic>Helicobacter pylori</jats:italic> eradication, were eligible for the study. Twenty patients were prospectively treated with 20 mg VPZ twice daily, 200 or 400 mg CAM twice daily, and 250 mg MNZ twice daily for 7 days. We also collected the data from 30 patients retrospectively treated with proton pump inhibitor (PPI), CAM, and MNZ. Safety was evaluated in patients completing an adverse effect questionnaire. <jats:italic>Results</jats:italic>. Both the intention-to-treat and per-protocol effectiveness of VPZ-based eradication were 100% (95% CI: 86.1–100%; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>n</mml:mi><mml:mo>=</mml:mo><mml:mn>20</mml:mn></mml:math>). The eradication rates of PPI-based regimen were 83.3% (95% CI: 65.3–94.4%) in the ITT and 82.7% (95% CI: 64.2–94.2%) in the PP analyses. Abdominal fullness was more frequent in VCM compared to PCM. However, all patients with VCM regimen had taken 100% of their course of medication. <jats:italic>Conclusion</jats:italic>. Triple therapy with VPZ, CAM, and MNZ is well tolerated and effective for eradicating <jats:italic>Helicobacter pylori</jats:italic> in patients allergic to penicillin. This study was registered in the UMIN Clinical Trials Registry as <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000018955">UMIN000016335</jats:ext-link>.</jats:p>