amoxicillin + rifabutin

Amoxicillin + rifabutin is a combination of two antibiotics used primarily in the treatment of *Helicobacter pylori* infection, especially as part of multi-drug regimens for patients with refractory or resistant *H. pylori*. Amoxicillin is a penicillin-class beta-lactam antibiotic that inhibits bacterial cell wall synthesis, while rifabutin is a rifamycin-class antibiotic that inhibits bacterial DNA-dependent RNA polymerase, thereby suppressing RNA synthesis and subsequent protein production. This combination may be used together with a proton pump inhibitor (PPI) to enhance efficacy against *H. pylori* by reducing gastric acidity and improving antibiotic activity[5]. The regimen is considered particularly useful in cases where standard therapies have failed due to resistance to other antibiotics such as clarithromycin or metronidazole[5].