Pharma 3 - Acid-Controlling Drugs (Chapter 50 ) Flashcards
Hydrochloric Acid (HCl)
- an acid that aids digestion and also serves as a barrier to infection.
- maintains stomach pH of 1 to 4.
- several substances stimulates secretion of the parietal cell to secrete HCl such as: food, caffeine, chocolate, & alcohol.
- excessive consumption of large, fatty meals or alcohol, also emotional stress, may result in excessive production of HCl and can lead to hypersecretory disorders like PUD.
Bicarbonate
a base that is a natural mechanism to prevent hyperacidity
Pepsinogen
an enzymatic precursor to PEPSIN, which is an enzyme that digests dietary proteins
Intrinsic Factor
a glycoprotein that facilitates gastric absorption of Vitamin B12
Mucus
protects the stomach lining from both HCl and digestive enzymes
Prostaglandins
have a variety of anti-inflammatory and protective functions
Glands in the Stomach:
➀ Cardiac
➁ Pyloric
➂ Gastric
➀ Cardiac Glands
→ located around the cardiac sphincter a.k.a. gastroesophageal sphincter
➁ Pyloric Glands
→ in the pyloric region and in the transitional area between the pyloric and the fundic zones
➂ Gastric Glands
→ in the fundus, also known as the greater part of the body of the stomach
→ largest in number
→ Primary importance in acid control
→ Composed of different types of Cells:
——– parietal, chief, mucous, endocrine, & enterochromaffin
Gastric Gland Cells
- the 3 most important cell types are:
1 - Parietal
2 - Chief
3 - Mucous
** These three cell types play an important role in the digestive process. When the balance of these cells and their secretions is impaired, acid-related diseases can occur.
** The most harmful these involve hypersecretion of acid and include peptic ulcer disease and esophageal cancer.
PARIETAL Cells
❶ PARIETAL Cells
→ produce and secrete Hydrochloric Acid (HCl)
→ primary site of action for many of the drugs used to treat acid-related disorders
→ Releases INtrinsic Factor, so B12 can be absorbed.
The wall of Parietal Cell contains 3 types of receptors:
== Acetylcholine (ACh), Histamine, and Gastrin.
* When any of these 3 receptors is occupied by its corresponding chemical stimulant, the parietal cell will produce and secrete Hydrochloric Acid (HCl).
CHIEF Cells
❷ CHIEF Cells
→ Secrete pepsinogen.
→ → Pepsinogen is a proenzyme (enzyme precursor) that becomes pepsin when activated by exposure to acid. Pepsin breaks down protein, therefore called a PROTEOLYTIC ENZYME.
MUCOUS Cells
❸ MUCOUS Cells
→ are mucous-secreting cells that are also called SURFACE EPITHELIAL CELLS. The secreted mucus serves as a protective coating against the digestive action of hydrochloric acid and digestive enzymes
Hyperacidity
Hyperacidity is often associated with Gastroesophageal Reflux Disease (GERD). This is the tendency of excessive and acidic stomach contents to back up or reflux, into the lower (and even upper) esophagus.
- Overtime, this condition can lead to more serious disorders such as erosive esophagitis and Barrett esophagus, a precancerous condition.
- Therefore, to prevent serious disorders from occurring and to promote patient comfort, GERD is aggressively treated.
Acid Related Diseases
Peptic Ulcer Disease (PUD) Helicobacter pylori (H. pylori)
Peptic Ulcer Disease
- term for gastric (stomach) or duodenal ulcers that involve digestion of the GI mucosa by the enzyme Pepsin.
- the defect can extend through the muscularis mucosa (smooth muscle layer)
- Because the process of ulceration is driven by the proteolytic (protein breakdown) actions of pepsin together with the caustic effects of hydrochloric acid, peptic ulcer disease and related problems are also referred to by the more general term = ACID-PEPTIC DISORDER
NSAID-Induced Peptic Ulcer Disease
≥ 60 yrs old history of PUD Concurrent steroid use Concurrent warfarin use Regular alcohol or tobacco use NSAID dosage higher than recommended Concurrent ASA-containing drugs/other NSAIDS Long-term NSAID use
