Lecture 13- Over the counter drugs- Digestive Problems Flashcards
What are some problems that affect the Gastrointestinal tract?
- peptice ulcers
- gastroesophageal reflux disease (heartburn)
- nausea and vomitting
- Motility problems; constipation adn diarrhea
Acid-peptic disease is a group of disorder involving either ____ acid secretion or erosion of the ____ ____ of the gastrointestinal tract.
excessive; mucosal lining.
Acid-peptice disease includes ____, ____, and ____ ____ ____
heartburn, peptic-ulcers, stress-related gastritis
The stomach is divided into 2 sections, what are they and which one is the top layer?
Fundus and the antrum; top layer is fundus
Which cells in the fundus are responsible for secretion of acid in the stomach?
parietal cells.
Which protom pump moves acid from the parietal cells into the gastric lumen?
H+/K+ ATPase
Which cells in the antrum respond to intraluminal dietary peptides to release gastrin which binds to ____ receptors on parietal cells?
G-cells and CCK
Gastrin also stimulates ____ cells (H-cells) to release histamine which binds to H ____ receptors on parietal cells.
enterochromaffin; H2
Which nerve stimulates postganglionic neurons of the enteric nervous sytem to release ____ which binds to muscarinic receptors (M3) on parietal cells?
vagus nerve; ACh
Is the vagus nerve part of the parasympathetic nervous system or the symphathetic nervous system?
parasympathetic
An increase in acid secretion causes ____ cells to release ____ and inhibit gastrin release from G-cells (____ feedback loop)
D cells; somatostain; negative
Fill in the blanks:
* G cells —> ____ —–> ____
* ____ —-> H cells —-> ____ —> H____ receptors
* ____ —> Acetylcholine —-> M3 receptors
* Increased Acid secretion —-> ____ —-> ____ —-> ____
- G-cells - gastrin - CCK
- Gastrin - H cells - Histamine - H2 receptors
- Vagus Nerve - ACh - M3 receptors
- Increased acid secretion - D cells - somatostain - gastrin inhibition
Antacids are ____ bases that neutralize stomach acid by reacting with protons in the lumen of the gut. When used regularly, in the large doses needed to raise stomach pH, antacids reduce the recurrence rate of ____ ____.
weak bases; peptice ulcers
The most common antacids include ____ hydroxide and ____ hydroxide.
Magesium (MgOH2) and aluminum (AlOH3)
Which antacid has a strong laxative effect and which one has a constipating acting?
Magnesium is a laxative
Aluminum has a constipating action
What is an example of a proton pump inhibitor which are lipophilic weak bases that diffuse into the parietal cell and inactivate the ____ ____ transporter?
Omeprazole ; H+/K+ ATPase
Prolonged use of omeprazole can lead to ____ because acid secretion inhibits gastrin release that may increase cancer risk.
hypergastrinemia
What is hypergastrinemia?
elevated levels of gastrin secreted in the stomach.
OTC anti- ____ can help when dealing with nausea and vomitting caused by motion sickness and other conditions.
emetics
Proton pump inhibitors will decrease the bioavailability of vitamin ____ and certain drugs that require acidity for their absorption.
B12
____ ____, which is an active ingredient in Peptobismol, can be used to treat ulcers.
Bismuth Subsalicylate
Bismuth Subsalicylate hydrolyzes in the gut to Bismuth ____ and ____ ____.
Bismuth oxychloride; salicylic acid
Salicyclic acid is absorbed in the gut and inhibits ____ synthesis (anti-inflammatory properties)
prostaglandin
____ is a theoclate salt, composed of diphenhydramine and 8-chlorotheophylline.
Dimenhydrinate
Dimenhydrinate acts as a ____ ____ but is an inverse agonist at the H1 receptor, driven by diphenhydramine.
competitive antagonist
Dimenhydrinate blocks ____ activity in the vestibular system, but less sedation than diphenhydramine as it is less potent.
histamine
Which one is less potent, dimenhydrinate or diphenhydramine?
dimenhydrinate
Gastrointestinal motility is controlled by ____ ____ ____ (enteric nervous system), neurons which are only present in the GIT.
intrinsic neural plexus
Removing ____ automatic control results in disorganized gastric activity (nausea or vomitting).
extrinsic
What is known as the second brain in our body?
Enteric nervous system
____ plexus provides motor innervation to the muscular layer of the gut which mediates peristalsis, outer layer
myenteric
____ plexus provides secretomotor (induce a gland to secret a substance) innervation to the mucosa, inner layer.
submucosal
Enteric neurons are predominantly ____ but release a lot of other neurotransmitter such as serotonin and dopamine.
cholinergic
The autonomic nervous sytem is divded into ____ and ____ system.
parasympathetic; sympathetic
All ____ganglionic neurons are cholinergic; they release acetylcholine.
pre
Postganglionic parasympathetic neurons are ____, whereas postganglionic sympathetic neurons are ____, they release noradrenaline
cholinergic; adrenergic
Acetylcholine binds to ____ receptors (M2) on GI smooth muscle leading to ____ (stimulates motility)
muscarinic; contraction
M2 receptors are G____ - coupled receptors
Gi
Postganglionic parasympathetic = ____ –> myenteric
cholinergic
Postganglionic sympathetic = ____ —> enteric
adrenergic.
____ are substances that loosen stool or stimulate bowel movement.
laxatives
What are the 4 types of laxatives?
- Bulk forming
- osmotic
- lubricant
- stimulant
Which laxatives contain naturally occuring plant fiber like psyllium and methyl cellulose that draw water into the stool to make them larger and easier to pass?
Bulk forming laxatives
Which laxatives contains ingredients like polyethylene glycol or magnesium that draw fluid into the bowel from nearby tissue?
osmotic laxatives
Which kind of laxative has glycerin suppositories that coat the surface of stools or anus to make it easier for stool to pass?
Lubricant laxatives
Which kind of laxative contains ingredients like senna and bisacodyl that causes the bowels to squeeze the stools out?
stimulant laxatives
What are the 2 types of bulk forming laxatives and what do they do?
Psyllium and methyl cellulose; they draw water into the stoll; they are plant fibers
What are the 2 types of osmotic laxatives and what do they do?
Polyethylene glycol and magnesium; they draw water into stoll from nearby tissues.
What are the 2 types of stimulant laxatives and what do they do?
Senna and bisacodyl; they stimulate the bowels to squeeze the stool out.
____ is a loose, watery stool that occurs when colon is unable to adequately absorb the liquid from the food and fluids you ingest.
Diarrhea
What are the 2 most common OTC treatment for diarrhea?
- Loperamide
- Bismuth subsalicylate
Like codeine, what else is a mu opioid agonist?
loperamide
mu opioid receptors are located on the ____ plexus which provides motor innervation of the gut, controls peristalsis
myenteric
Loperamide has ____ (strong/weak) analgesic activity but effectively slows gut motility.
weak.
How is loperamide different from codeine?
- less analgesic
- less respiratory depression
- no effect on cough
Loperamide is a ____ agonist but has weak analgesic activity.
full
Loperamide is a substrate for ____ (aka P-gp). P-gp is located on endothelial cells at the ____ ____ ____ and actively pumps drugs out of the brain.
P-glycoportein; blood brain barrier
Loperamide brain levels are kept ____ (high/low) due to active extrusion by P-gp.
low
P-gp is inhibited by tricyclic antidepressents such as ____.
amitriptyline.
Blocking P-gp will ____ (increase/decrease) brain concentration of loperamide.
increase
