End for Exam 2 (GI drugs) Flashcards
what are the basic functions of the GIT? (3)
- Transport food
- Secrete digestive enzymes
- Absorb nutrients
what are the factors that influence the GIT? (4)
- Parasympathetic and sympathetic nervous systems
- Prostaglandin E
- Hydrochloric acid (HCl) production in the stomach
- Irritating compounds and bacterial toxins
where is prostaglandin E produced?
GI cells
what is the function of prostaglandin E? (4)
- inc. intestinal mucus production
- dec. HCl acid secretion
- inc. intestinal motility
- inc. blood supply to GI tract
where is hydrochloric acid (HCI) produce?
parietal cells in the GIT
what stimulates the parietal cells to produce hydrochloric acid (HCI)? (3)
- Histamine
- Gastrin
- Acetylcholine
Diarrhea
abnormally frequent discharge of fecal matter of increased volume and fluid content
what are some causes of diarrhea? (4)
- Maldigestion or malabsorption of food
- Hypersecretion of intestinal fluid
- Increased permeability of intestinal mucosal blood vessels
- increased intestinal motility
what can cause hypersecretion in the GIT?
bacterial infection
what can cause increased permeability?
Caused by inflammation
what can cause inflammation in the GIT?
IBD or parasite
what can cause an increase of Intestinal motility?
toxins and any type of irritation
what are most antidiarrheal drugs used to treat?
symptom but not the primary cause of the diarrhea
what the categorites of antidiarrheals? (2)
- modify intestinal motility
2. act as adsorbents and/or protectants
how do antidiarrheals that modify intestinal motility work?
slow movement of bowel contents
what kind of antidiarrheals modify intestinal motility? (2)
- opioid analgesics
2. anticholinergics
why are opioid analgesics and anticholinergics not frequently used?
a large proportion of diarrheas in small animals involve decreased motility
what kind of antidiarrheals act as adsorbents and/or protectants? (3)
- activated charcoal
- kaolin and pectin
- bismuth subsalicylate
what are some examples of opiod analgesics antidiarrheals? (3)
- diphenoxylate (Lomotil)
- paregoric (tincture of opium)
- loperamide (Imodium)
what class of drugs are opiod analgesics antidiarrheals?
Controlled drugs
what is the concerns with using opiod analgesics antidiarrheals?
Increase contact time between toxins and mucosa
what is a benefit to using opiod analgesics antidiarrheals?
Mask pain associated w/ disease
How do opiod analgesics antidiarrheals work?
Increase segmental contrations
how ca Increase segmental contrations Help?
work as a trap to keep digesta in intestinal tract longer to hep absorption of water.
How do anticholinergics work as an antidiarrheal?
Block the effect of acetylcholine
why are anticholinergics not commonly used as an antidiarrheal in small animals?
In small animals increased motility is not a common cause of diarrhea
what are some example of anticholinergics? (3)
- atropine
- isopropamide (Darbazine),
- aminopentamide (Centrine)
what kind of diarrheal cases are anticholinergics effective against
diarrhea caused by increased colonic contractions
what is the purpose of Adsorbents and Protectants?
Prevent irritating compounds and bacterial toxins from contacting the intestinal mucosa
how does Bismuth subsalicylate work as a absorbent/protectant? (3)
- bismuth carbonate coats intestinal mucosa
- salicylate decreases fluid secretion
- Decreases fluid secretion by reducing inflammation
what are some example of Adsorbents and Protectants? (3)
- Activated charcoal
- Kaolin and Pectin (Kaopectate)
- Bismuth subsalicylate (Pepto-Bismol)
how does Activated charcoal work as a absorbent/protectant?
adsorbs enterotoxins to its surface
how does Kaolin and Pectin work as a absorbent/protectant? (2)
- adsorbs enterotoxins
2. coats the intestinal bowel wall
how do laxatives work?
Increase the fluid content of feces to facilitate passage
what are the categories of laxative? (2)
- Irritant laxatives
2. Bulk laxatives
what are some example of irritant laxatives? (2)
- castor oil
2. phenolphthalein
how do irritant laxatives work? (2)
- irritate the intestinal mucosa
2. increase fluid secretion and peristaltic activity
what are some examples of bulk laxatives? (5)
- bran
- methylcellulose
- psyllium (Metamucil)
- magnesium salts (Milk of Magnesia, Epsom Salts)
- phosphate salts (Fleet Enema)
how do bulk laxatives work?
osmotically pull water into intestinal lumen
what are some conderns with bulk laxatives? (2)
- salts may dehydrate the animal
2. absorption of minerals from intestine may cause electrolyte imbalance
how do lubricants work?
Make stool more slippery for easy passage through the bowel
what are some examples of lubricants? (3)
- mineral oil
- cod liver oil
- white petrolatum
what is he concern with long term use of lubricants?
can decrease absorption of lipid-soluble vitamins
what combination of lubricants is Catlax?
cod liver and while petrolatum
what is the purpose of stool softeners?
Reduce surface tension of the feces allowing water to penetrate dry stool