What is the first-line treatment regimen for H. pylori infection known as "CAP" therapy?

The first-line treatment regimen for H. pylori infection, commonly referred to as "CAP" therapy, consists of Clarithromycin, Amoxicillin, and a Proton Pump Inhibitor (PPI). This combination is effective because it utilizes two antibiotics, Clarithromycin and Amoxicillin, to combat the bacteria and a PPI to reduce gastric acid secretion, which promotes healing of the gastric mucosa and enhances the efficacy of the antibiotics.

Clarithromycin serves as a macrolide antibiotic that inhibits bacterial protein synthesis, while Amoxicillin provides a beta-lactam antibiotic that disrupts cell wall synthesis in bacteria. The combination strengthens the overall treatment by attacking H. pylori from different angles, making it more difficult for the bacteria to develop resistance.

The PPI component is critical as it not only aids in the healing of ulcers but also creates a more favorable pH environment for the antibiotics to work. This synergistic effect of antibiotics plus acid suppression is key to the successful eradication of H. pylori.

Other regimens may involve different antibiotic combinations or drug classes, but the specific "CAP" therapy with Clarithromycin, Amoxicillin, and a PPI is the established first-line approach for H. pyl