Download Chapter 8 GI Drugs Quiz Yourself 1. H2 receptors are special

Chapter 8 GI Drugs
Quiz Yourself
1. H2 receptors are special histamine receptors located in the gastric parietal cells
lining the stomach. When stimulated, these receptors trigger the release of gastric
acid. H2 blocker drugs block H2 receptors and prevent the release of gastric acid.
2. The trade name Antivert combines the syllables anti- from antiemetic and vert from
vertigo to show that the therapeutic effect of this drug is to prevent the symptoms of
nausea and vomiting from vertigo.
In the trade name Asacol, the Asa- refers to the drug 5-ASA, and col refers to
colon, the site of the drug’s effect.
The trade name Pepto-Bismol refers to the anatomic adjective peptic, while Bismol
refers to the drug bismuth.
The trade name Tagamet was derived from the words antagonist (describing the
effect of the drug) and cimetidine (the generic name of the drug).
3. Antacid drugs are weak bases that exert a therapeutic effect by neutralizing
hydrochloric acid. This raises the pH of the stomach contents, which decreases
mucous membrane irritation. This also inhibits the action of pepsin so that it does not
break down the exposed mucous membranes.
H2 blocker drugs block H2 receptors and prevent the release of gastric acid.
Proton pump inhibitor drugs decrease gastric acid by blocking the final step of
acid production within the gastric parietal cell. This final step involves an enzyme
system known as the proton pump.
Misoprostol (Cytotec) is a synthetic prostaglandin drug that is given to protect
the gastric mucosa when natural prostaglandins are inhibited by aspirin or NSAIDs.
Sucralfate (Carafate) acts topically on the ulcer surface to bind directly to it,
forming a protective barrier over the ulcer to allow it to heal.
4. Esomeprazole (Nexium).
5. Anticholinergic drugs are useful in treating gastrointestinal spasms associated with
irritable bowel syndrome. The neurotransmitter acetylcholine acts on cholinergic
receptors to stimulate the release of acid, to stimulate muscular contractions, and to
begin peristalsis to move food through the GI tract. Anticholinergic drugs can be
given to block the effects of acetylcholine, decrease the amount of acid, and stop
spasms.
6. Narcotic drugs are useful in treating diarrhea because a common side effect of these
drugs is constipation, so this side effect then becomes the therapeutic effect in
treating diarrhea.
7. Osmotic laxative drugs use osmosis and osmotic pressure to attract water from the
blood into the intestine to soften the stool.
Examples:
Epsom salt
glycerin (Colace suppository, FleetBabylax)
lactulose (Cephulac)
milk of magnesia (MOM, Phillips’ Milk of Magnesia)
Bulk-producing laxative drugs contain indigestible dietary fiber and other
substances that absorb and hold water in the intestines to soften the stool.
Examples:
methylcellulose (Citrucel)
polycarbophil (FiberCon)
psyllium (Fiberall, Metamucil, Perdiem)
Stool softener drugs are emulsifiers that allow fat in the stool to mix with water
to soften the stool.
Example:
docusate (Colace, Surfak)
Chloride channel laxative drugs stimulate chloride channels in the mucosa of the
intestinal wall. This causes fluid to flow into the intestine to soften the stool.
Example:
lubiprostone (Amitiza)
Irritant/stimulant laxative drugs act directly on the intestinal mucosa to stimulate
peristalsis.
Examples:
bisacodyl (Correctol, Dulcolax, Feena-mint)
cascara
sennosides (ex-lax, Fletcher’s Castoria, Senokot)
8. Aminosalicylic acid (ASA) decreases intestinal inflammation in ulcerative colitis by
blocking the production of prostaglandins that cause the inflammation in ulcerative
colitis.
9. Drugs used to treat motion sickness or vertigo act either by blocking inner ear stimuli
from reaching the chemoreceptor trigger zone and the vomiting center in the brain
or by reducing the sensitivity of the inner ear to motion.
10. Lipase inhibitor drugs and appetite suppressant drugs are two categories of drugs
used to treat obesity. Lipase inhibitor drugs bond to lipase so that it cannot break
down dietary fat in the intestine. The fat is excreted, not absorbed into the blood.
Appetite suppressant drugs affect dopamine or serotonin levels in the satiety center
of the brain.
11. a. H2 blocker drug for heartburn, peptic ulcers, and GERD
b. Stool softener laxative drug for constipation
c. Combination anticholinergic and narcotic drug for diarrhea
d. Anticholinergic drug for diarrhea
e. Chloride channel laxative drug for constipation
f. Aminosalicylic acid drug for ulcerative colitis
g. Combination antacid drug for heartburn and peptic ulcers
h. H2 blocker drug for heartburn, peptic ulcers, and GERD
i. Proton pump inhibitor drug for peptic ulcer disease
j. Lipase inhibitor drug for obesity
k. Antiemetic drug used to treat nausea and vomiting
l. H2 blocker drug for heartburn, peptic ulcers, and GERD
m. Antiemetic drug used to treat motion sickness and vertigo
n. Used to treat gallstones
Clinical Applications Questions
1. a. ranitidine (Acid Reducer is the trade name)
b. H2 blocker drug
c. 75 mg
d. An over-the-counter drug. It says “nonprescription strength” at the top of the label.
e. Zantac
2. a. simethicone
b. Softgel
c. 180 mg
d. Simethicone acts by changing the surface tension of air bubbles trapped in the GI
tract and allowing them to be expelled.
3. a. Dulcolax
b. Laxative drugs
c. docusate sodium
d. Liquid gels
4. Zantac 150 milligram tablets. Dispense 100. Take one twice a day.