21.3 : 消化性溃疡的抑酸药物：质子泵抑制剂

Two of the main contributors to peptic ulcer formation are H. pylori infections or NSAID use, both facilitating gastric acid production.

Gastric acid is secreted by proton pumps located in the parietal cell.

The HCO₃^_ ions inside the cell exchanges for Cl^- ions, which, along with K⁺ ions, enter the gastric lumen.

The proton pumps exchange the luminal K⁺ ions with the cellular H⁺ ions. These ions combine to produce HCl acid.

These pumps can be inhibited by proton pump inhibitors, decreasing gastric acid secretion.

These inhibitors are administered as enteric-coated tablets or delayed-release capsules that dissolve in alkaline pH.

The prodrug travels through the bloodstream and accumulates in the acidic canaliculi, converting to its active form.

The activated drug binds irreversibly with the sulfhydryl group, inactivating the pump. It blocks H⁺ ions transport and suppresses gastric acid secretion.