Acid Controlling Drugs Flashcards
What substances secrets stomach!
Hydrochloric acid
Bicarbonate
Pepsinogen
Intrinsic factor
Mucus
Prostaglandins
What is HCL?
Hydrochloric acid
-an acid secreted by parietal cells in the lining of the stomach that maintains the environment of the stomach at a pH 1-4.
-aids in digestion
-serves as barrier to infection
What is bicarbonate?
A base that is natural mechanism to prevent hyperacidity
What is pepsinogen?
An enzymatic precursor to pepsin, an enzyme that digest dietary proteins
What is intrinsic factor?
A gylcoprotein that facilitates gastric absorption of Vit B 12
What is mucus?
Protects stomach lining from both hydrochloric acid and digestive enzymes
Prostaglandins
Have a variety of anti-inflammatory and protective function
3 primary types of glands in the stomach
Cardiac
Gastric
Pyloric
Where is cardiac gland located?
Around cardiac sphincter also know as gastroesophageal sphincter
Location of gastric glands
Fundus the greater part of the body of the stomach
Location of pyloric gland
Pyloric region
What is gastric glands?
Highly specialized secretary glands composed of several different types of cells: parietal
Chief
Mucous
Endocrine
Enterochromaffin
What are three most important cell types?
Parietal cells
Chief cells
Mucous cell
What does parietal cell produce and secrete?
HCL
They are the primary site of action of many of the drugs used to treat acid-relates disorders
What chief cells secrete?
Pepsinogen a proenzyme that becomes pepsin when activated by exposure to acid
What does pepsin do in stomach?
Breaks downs proteins, smaller polypeptides, and amino avid
How is pepsin referred?
Proteolytic enzyme
What is another name for mucous cell and what they do?
Surface epithelial cells and they ate mucus secreting cells
What is function of the mucous?
Serves a protective coating agains the digestive action of HCL and digestive enzymes
What happens when the balance between three cells and their secretions is impaired?
Acid related disease can occur
What is the most harmful disease that can occur
It involves acid hyper secretion and includes peptic ulcer disease PUD and esophageal cancer
What is the most common acid relates disease?
Mild to moderate hyperacidity such as indigestion sour stomach heartburn and acid stomach
What substance can secrete HCL by the parietal cell?
Certain food such as chocolate
Caffein
Alcohol
Emotional stress
Which cell is primary target for many of the most effective drugs for treatment of acid related disorders
Parietal cells
What 3 types of the receptors can you find in wall of parietal cells
Acetycholine ACh
Histamine
Gastrin
What happens when these receptors is occupied y its corresponding chemical stimulant?
The parietal cell will produce and secrete HCL
What is the proton pump?
The hydrogen-potassium -adenosine triposphatase ATPase a pump for transport of hydrogen ions located in parietal cell. If energy is presented the proton pump will be activated and the pump will be able to transport hydrogen ions needed to produce HCL
What drives the proton pump for ACh and gastrin receptor
Calcium ions
What drives proton pump for histamine receptor?
Production of adenylate cuclase which converts adenosine triphosphate ATP to cyclic adenosine monophosphate cAMP which provides energy for the proton pump
stress ulcer prophylaxis or therapy that prevents sever GI damage is undertaken in which cases?
Almost every critically ill patient in Crictial Care Unit CCU and for many patients on general medical surgical units
Factors related to stress related mucosal damage
Decrease blood flow
Mucosal ischema
Hypoperfusion
Reperfusion injury
What is curling ulcer
Acute peptic ulcer of duodenum that occurs in patients with sever burns resulting decreased blood volume which leads to ischemia and cell necrosis of the gastric mucosa
What is antacids
Basic compounds to neutralize stomach acids
How does the bicarbonate reacts with stomach HCL
Release carbon dioxide gas that is quickly absorbed but sometimes results in release of the gas as a burp
What is alginate
A tasteless substance dervied from kelp or seaweed
It is not antacids but creates a physical gel barrier floating between gastric acid and esophagus which prevents acid to go into esophagus
Example of antacid containing alginate sodium
Gaviscon
Peppermint
Most common added to antacids and it relaxes the lower esophageal sphincter so that gas can be released
Why would not peppermint good for patients with GERD
A stomach acid would flow back into esophagus
What other antacid formulation exits
Aluminum and calcium based antacid formulation
What do aluminium and calcium based antacid formulation that includes magnesium contribute to
Contributes acid neutralizing capacity and counteracts the constipating effects of aluminium and calcium
Which calcium salts is commonly used
Calcium carbonate
What condition can calcium antacids lead to
Developmental of kidney stone and increased gastric acid secretion
Which patient should avoid antacids containing magnesium
Kidney failure patient
How does sodium bicarbonate work
Highly soluble antacid with quick onset but short duration of action
What does antacids promote
Gastric mucosal defensive mechanisms by stimulating the secretion of mucus, prostaglandins and bicarbonate from the cells i side the gastric glands
What does mucus serve
Mucus serves as a protective barrier against the destructive actions of HCL
What does bicarbonate do?
Buffers acidity of HCL
What does prostaglandins do?
Prevents histamine from binding to its corresponding parietal cell receptor which inhibits production of adenylate cyclase. Without cyclase no cAMP can be formed and no second messenger is available to activate proton pump
What is primary drug effect of antacids?
The reduction of symptoms associated with various acid-related disorders such as pain and reflux
Indications for antacids
Acute relief of symptoms associated with peptic ulcer gastritis gastric hyperacidity and reflux
Contraindication of antacids
Allergy to specific drug product
Sever kidney failure
Electrolyte disturbance
GI obstruction
Adverse reactions
Magnesium preparation particularly milk of magnesia can cause diarrhea
Adverse reactions antacids
Aluminium and calcium containing formulation result in constipation
Calcium can cause kidney stones and rebound hyperacidity or acid rebound
Other adverse effects
Long term self medication with antacids may mask symptoms of serious underlying condition such as bleeding ulcer or malignancy
