This chapter will be most useful after having a basic understanding of the material in Chapter 45, Pharmacotherapy of Gastric Acidity, Peptic Ulcers, and Gastroesophageal Reflux Disease in Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12th Edition. In addition to the material presented here, the 12th Edition contains:
A description of the physiology of gastric secretion
Therapeutic strategies for the treatment of specific acid-peptic disorders
Table 45-2 which shows the composition and acid neutralizing capacities of popular antacid preparations
Identify the sites in the gastric parietal cell where drugs act to suppress acid secretion.
Describe the mechanism of action of proton pump inhibitors, H2 receptor antagonists, and prostaglandin analogs to suppress gastric acid secretion.
Describe the limitations to the use of H2 receptor antagonists in chronic acid suppression.
Identify potential drug interactions with proton pump inhibitors and H2 receptor antagonists.
Describe the mechanism of action of drugs that enhance gastric cytoprotection.
Describe the recommendations for therapy of gastroesophageal reflux disease (GERD) and peptic ulcer disease.
Understand the role of Helicobacter pylori infection in peptic ulcer disease and the therapeutic principles for its eradication.
Describe appropriate therapy for NSAID-induced ulcers.
DRUGS INCLUDED IN THIS CHAPTER
Cimetidine (TAGAMET, others)
Famotidine (PEPSID, others)
Nizatidine (AXID, others)
Omeprazole (PRILOSEC, others)
Ranitidine (ZANTEC, others)
Sucralfate (CARAFATE, others)
MECHANISMS OF ACTION OF DRUGS USED TO TREAT GASTRIC ACID DISEASES |Favorite Table|Download (.pdf) MECHANISMS OF ACTION OF DRUGS USED TO TREAT GASTRIC ACID DISEASES
|DRUG CLASS ||DRUGS ||MECHANISM OF ACTION |
|H2 Receptor Antagonists || |
|Competes with histamine for binding to H2 receptors on the basolateral membrane of parietal cells (see Figure 32-1) |
|Proton Pump Inhibitors || |
|The activated form binds covalently with sulfhydryl groups on cysteine in the H+,K+-ATPase located on the luminal membrane of the parietal cell to suppress acid secretion (see Figure 32-1) |
|Prostaglandin Analog ||Misoprostol ||Binds to the EP3 receptor on parietal cells decreasing cyclic AMP and gastric acid secretion (see Figure 32-1) |
|Cytoprotective Agent ||Sucralfate ||Forms a viscous, sticky polymer that adheres to epithelial cells and ulcer craters and is cytoprotective |
|Antacids ||Various over-the-counter (OTC) products ||Neutralize gastric acid |
|Bismuth ||Various OTC products ||Binds to the base of ulcers and promotes mucin and bicarbonate production |
Physiological and pharmacological regulation of gastric secretion: the basis for therapy of acid-peptic disorders. Shown are the interactions among an enterochromaffin-like (ECL) cell that secretes histamine, a ganglion cell of the enteric nervous system (ENS), a parietal cell that secretes acid, and a superficial epithelial cell that secretes mucus and bicarbonate. Physiological pathways, shown in solid black, may be stimulatory (+) or inhibitory (−). 1...