GASTRIC ACID INHIBITORS STOMACH ACID

Gastric acid inhibitors are medications that reduce the production of stomach acid. They are different from antacids, which act on stomach acid after it has been produced and released into the stomach. Purpose
Gastric acid inhibitors are used to treat conditions that are either caused or made worse by the presence of acid in the stomach. These conditions include gastric ulcers; gastroesophageal reflux disease (GERD); and Zollinger-Ellison syndrome, which is marked by atypical gastric ulcers and excessive amounts of stomach acid. Gastric acid inhibitors are also widely used to protect the stomach from drugs or conditions that may cause stomach ulcers. Medications that may cause ulcers include steroid compounds and nonsteroidal anti-inflammatory drugs (NSAIDs), which are often used to treat arthritis. Gastric acid inhibitors offer some protection againstthe stress ulcers that are associated with some types of illness and with surgery.

Description
There are two types of gastric acid inhibitors, H2-receptor blockers and proton pump inhibitors. H2-receptor blockers are a type of antihistamine. Histamine, in addition to its well-known effects in colds and allergies, also stimulates the stomach to produce more acid. The receptors (nerve endings) that respond to the presence of histamine are called H2 receptors, to distinguish them from the H1 receptors involved in causing allergy symptoms. The most common H2-receptor blockers are cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid), and ranitidine (Zantac).

The proton pump inhibitors (PPIs) are drugs that block an enzyme called hydrogen/potassium adenosine triphosphatase in the cells lining the stomach. Blocking this enzyme stops the production of stomach acid. These drugs are more effective in reducing stomach acid than the H2-receptor blockers. The PPIs include such medications as omeprazole (Prilosec), esomeprazole (Nexium), lansoprazole (Prevacid), pantoprazole (Protonix) and rabeprazole (AcipHex).

Recommended dosages
The recommended dosage depends on the specific drug; the purpose for which it is being used; and the route of administration, whether oral or intravenous. Patients should check with the physician who prescribed the medication or the pharmacist who dispensed it. If the drug is an over-the-counter preparation, patients should read the package labeling carefully, and discuss the correct use of the drug with their physician or pharmacist. This precaution is particularly important with regard to the H2-receptor blockers, because they are available in over-thecounter (OTC) formulations as well as prescription strength.

The two are not interchangeable; OTC H2-receptor blockers are only half as strong as the lowest available dose of prescription-strength versions of these drugs. Patients should not use the over-the-counter preparations as an alternative to seeking professional care. For some conditions, particularly stomach ulcers, acid-inhibiting drugs may relieve the symptoms, but will not cure the underlying problems, which require both acid reduction and antibiotic therapy. Gastric acid inhibitors work best when they are taken regularly, so that the amounts of stomach acid are kept low at all times. Patients should check the package directions or ask the physician or pharmacist for instructions on the best way to take the medicine.

Precautions
There are relatively few adverse reactions when gastric acid inhibitors are used for one to two doses before or just after surgery, The side effects listed below are most often seen with long-term use.