Proton pump inhibitors

Proton pump inhibitors

Proton pump inhibitors disrupt chemical binding in stomachcells to reduce acid production, lessening irritation and allowing peptic ulcers to better heal. They include:

·                 esomeprazole

·                 lansoprazole

·                 omeprazole

·                 pantoprazole

·                 rabeprazole.

Pharmacokinetics

Proton pump inhibitors are given orally in enteric-coated formulas to bypass the stomach because they’re highly unstable in acid. When in the small intestine, they dissolve and are absorbed rapidly.

Metabolism and excretion

These medications are highly protein-bound and are extensively metabolized by the liver to inactive compounds and then eliminat-ed in urine.

Pharmacodynamics

Proton pump inhibitors block the last step in the secretion of gas-tric acid by combining with hydrogen, potassium, and adenosine triphosphate in the parietal cells of the stomach.

Pharmacotherapeutics

Proton pump inhibitors are indicated for:

·         short-term treatment of active gastric ulcers

·                 active duodenal ulcers

·                 erosive esophagitis

·                 symptomatic GERD unresponsive to other therapies

·                 active peptic ulcers associated with H. pylori infection, in com-bination with antibiotics

·                 long-term treatment of hypersecretory states such as Zollinger-Ellison syndrome.

Drug interactions

Proton pump inhibitors may interfere with the metabolism of di-azepam, phenytoin, and warfarin, causing increased half-life and elevated plasma levels of these drugs.

Absorbing talk

Proton pump inhibitors may also interfere with the absorption of drugs that depend on gastric pH for absorption, such as ketocona-zole, digoxin, ampicillin, and iron salts. (See Adverse reactions toproton pump inhibitors.)