Efficacy and Safety of Levofloxacin‐ Versus Moxifloxacin‐Based Nitazoxanide Quadruple Therapy as Second‐Line Treatment for Helicobacter pylori in Egypt: A Randomized Multicenter Trial

BACKGROUND: Eradication of Helicobacter pylori remains challenging in countries with high antimicrobial resistance and limited access to bismuth-based therapies. Quinolone-containing regimens represent a practical alternative, yet comparative data between levofloxacin- and moxifloxacin-based nitazoxanide quadruple therapies are scarce, particularly in Egypt. This multicenter trial evaluated the efficacy, safety, and tolerability of two nitazoxanide-based second-line regimens after failure of first-line eradication therapy. METHODS: In this prospective, randomized, single-blind, parallel-group study conducted at six Egyptian centers, adults aged 18-70 years with documented failure of first-line H. pylori therapy were enrolled. Patients were randomized 1:1 to receive either LNDL (levofloxacin 750 mg once daily, nitazoxanide 500 mg twice daily, doxycycline 100 mg twice daily, lansoprazole 30 mg twice daily) or MNDL (moxifloxacin 400 mg once daily with the same adjunct medications) for 14 days. Eradication was assessed using a stool antigen test ≥ 4 weeks after treatment. Safety, tolerability, and symptom improvement were recorded. Analyses were performed using both intention-to-treat (ITT) and per-protocol (PP) populations. RESULTS: A total of 430 patients were randomized. ITT eradication rates were 65.6% (95% CI: 59.2% - 72%) for LNDL and 74.9% (95% CI: 69% - 80.7%) for MNDL (p = 0.035). PP eradication rates were 70.9% (95% CI: 64.5% - 77.2%) and 78.5% (95% CI: 72.9% - 84.2%), respectively (p = 0.076). Among patients previously treated with levofloxacin, MNDL achieved significantly higher eradication rates than LNDL (65.8%, 95% CI: 50-81.6 vs. 42.6%, 95% CI: 29-56.2, p = 0.028). Both regimens produced significant symptom improvement and were well tolerated; no serious adverse events occurred. CONCLUSION: Both nitazoxanide-based quinolone quadruple regimens demonstrated modest but clinically relevant efficacy as second-line therapy. Moxifloxacin showed superior performance in patients with prior levofloxacin exposure. These findings support the use of moxifloxacin-based rescue therapy in settings with high resistance and limited access to bismuth-containing regimens.