Acid Controlling Drugs Pathology

Acid Controlling Drugs Pathology
Chapter 51

Pathophysiology
Definitions:
HCL: an acid that aids digestion and also serves as a barrier to infection
Bicarbonate: a base that is a natural mechanism to prevent hyperacidity
Pepsinogen: an enzymatic precursor to pepsin, an enzyme that digests dietary proteins
Intrinsic factor: a glycoprotein that facilitates gastric absorption of vit B12
Mucus: for protection of the stomach lining from both HCl and digestive enzymes
Prostaglandins (PGs): have a variety of antiinflamatory and protective functions.

I The stomach can be divided into three functional areas. Each area has specific glands with which it is associated. These glands are composed of different cells which secrete different substances.
A. Cardiac:
B. Fundic/gastric:
1. most numerous
2. of primary importance to the discussion of acid-related disorders and drug therapy.
3. Highly specialized secretory glands composed of several different types of cells.
a. parietal: (see fig. 49-2)
i. produce and secrete HCl
ii. pimary site of action for many acid controlling drugs
b. chief:
i. secrete pepsinogen, a proenzyme
ii. pepsinogen becomes pepsin when activated by exposure to acid
iii. pepsin breaks down proteins (proteolytic)
c. mucoid/mucous:
i. mucus secreting cells (surface epithelial cells)
ii. provide a protective mucous coat
iii. protect against self-digestion by HCl
d. endocrine
e. enterochromaffin
C. pyloric:
II When the three main gastric cells or their secretions are impaired, acid related diseases can occur.
A. hypersecretion
1. the most harmful of the acid related diseases
2. include:
a. peptic ulcer disease (PUD)
b. esophageal cancer
B. mild to moderate hyperacidity
1. most common condition
2. overproduction of HCl by the parietal cells
3. include:
a. indigestion, sour stomach, heartburn, acid stomach
b. GERD
C. Helicobacter pylori is a contagious diseases.
1. bacteria found in GI tract of 90% of patients with duodenal ulcers and 70% of those with gastric ulcers
2. antibiotics are used to eradicate (tetracycline)
III Hydrochloric Acid (HCl)
A. Secreted by the parietal cells when stimulated by food
B. Maintains stomach pH of 1 to 4
C. Aids in the proper digestion of food
D. Serves as one of the body’s defenses against infection in GI tract
E. Excretion also stimulated by:
1. large fatty meals
2. excessive amounts of alcohol
3. emotional stress
F. The primary target for many of the most effective drugs for the treatment of acid related disorders.