Susceptibility‐guided therapy for Helicobacter pylori‐infected penicillin‐allergic patients: A prospective clinical trial of first‐line and rescue therapies

Background Helicobacter pylori (H pylori) treatment remains a challenge for penicillin‐allergic patients. Aim To evaluate the efficacy and tolerability of susceptibility‐guided first‐line and rescue treatment in H pylori‐infected penicillin‐allergic patients. Methods Consecutive H pylori‐infected patients with penicillin allergy received a 14‐day triple or quadruple therapy based on susceptibility to clarithromycin, levofloxacin, and metronidazole. All received esomeprazole 20 mg twice a day. Metronidazole‐susceptible infections received metronidazole plus clarithromycin or levofloxacin triple therapy if susceptible. Clarithromycin‐ and levofloxacin‐resistant infections received metronidazole plus tetracycline triple therapy. Metronidazole‐resistant infections received a bismuth—high‐dose metronidazole plus clarithromycin or levofloxacin quadruple therapy. Triple‐resistant infections received classical bismuth quadruple therapy with high‐dose metronidazole. Antimicrobial susceptibility was assessed using the E test method. Results 112 patients were entered (34.8% men, average 47.1 years). Infections in 83.8% (31/37) of treatment‐naive subjects and 12.0% (9/75) (P