Gastrointestinal Tract Disorders Flashcards
A major cerebral center that lies near the medulla
Chemoreceptor Trigger Zone (CTZ)
A major cerebral center that causes vomiting when stimulated
Vomiting Center
Drugs used to induce vomiting
Emetics
Hyperosmolar are which type of laxatives
Osmotics
Lubricants and stool softeners used to prevent constipation are what type of laxative
Emollients
Nonpharmacologic Measure for vomiting include:
Weak tea
Flat soda
Gelatin
Pedialyte
Gatorade
Crackers
Dry toast
Avoid spicy/fatty foods
When do we use IV fluids to treat vomiting?
If they patient has symptoms of dehydration.
Side effects of antihistamines include:
Drowsiness, dry mouth, constipation, urinary retention
When should motion sickness meds be taken?
30 minutes to 1 hour before travel
Antihistamines and anticholinergics help with nausea by:
Acting primarily on the vomiting center. Decreasing stimulation of CTZ and vestibular pathways.
Hydroxyzine (Vistaril) and Promethazine (Phenergan) are what type of antiemetic?
Antihistamine
True or False: Promethazine (Phenergan) can be used in patients with narrow-angle glaucoma.
False
Scopolamine is what type of antiemetic?
Anticholinergic
The 3 categories of dopamine antagonists used as antiemetics are:
Phenothiazines(Compazine), butyrophenones(Haldol), and benzodiazepines(Ativan)
Prochlorperazine (Compazine) is an example of which type of dopamine antagonist?
Phenothiazine
Phenothiazines are also used to treat what type of disorders?
Mental and emotional disorders, used in smaller doses as antiemetics
Phenothiazines work by:
Blocking dopamine receptors in CTZ suppressing emesis
Haloperidol and droperidol are which type of dopamine antagonist?
Butyrophenones
True or False: Butyrophenones have the same mechanism of action as phenothiazines.
True
Side effects of Butyrophenones include:
EPS and hypotension
Diazepam and Lorazepam are which type of dopamine antagonist?
Benzodiazepines
Ondansetron (Zofran), granisetron, dolasetron, and palonosetron are what type of antiemetic?
Serotonin antagonists
Common side effects of serotonin antagonists include:
Headache, dizziness, diarrhea, fatigue
Dexamethasone and methylprednisolone are which type of drug?
Glucocorticoids (corticosteroids)
Dronabinol and Marinol are which type of drug?
Cannabinoids
How are Cannabinoids administered to help alleviate nausea and vomiting caused by chemotherapy?
They are taken by mouth 1-3 hours before chemo and every 2-4 hours after for a max of 6 doses/day.
How does metoclopramide (Reglan) work?
It blocks dopamine receptors in the CTZ.
True or False: Metoclopramide (Reglan) is routinely used in children.
False, EPS occur more frequently in children
True or False: It is better to use nonpharmacological treatments for nausea and vomiting in early pregnancy.
True
When should emetics not be used after ingestion of a toxic substance?
When the person has ingested caustic substances like bleach, lye, ammonia, toilet cleaners, or battery acid. Neither should they be used for ingestion of petroleum distillates.
What should be used instead of emetics when vomiting is contraindicated?
Activated charcoal
Nonpharmacological treatments for diarrhea include:
Clear liquids, oral solutions (gatorade, pedialyte), IV electrolyte solutions
True or False: The use of Loperamide (Imodium) can prolong the duration of Traveler’s diarrhea.
True
Diphenoxylate w/ Atropine (Lomotil) and Loperamide (Imodium) are which type of antidiarrheal?
Opiates
Why is atropine added to diphenoxylate?
It is an anticholinergic drug that decreases intestinal cramping, motility, and secretions. It also helps to decrease the incidence of abuse.
True or False: Opiates that are used for diarrhea cannot cause respiratory depression.
False
Adsorbents work by:
Coating the wall of the GI tract and adsorbing bacteria and toxins.
Kaolin-pectin and bismuth subsalicylate (Pepto-Bismol) are examples of which type of antidiarreheal?
Adsorbents
Nonpharmacological treatments for constipation include:
Fiber, water, exercise, and routine bowel habits.
Lactulose is an example of which type of laxative?
Osmotic (Saline)
What are the differences between laxatives, cathartics, and purgatives?
Laxatives promote soft stool. Cathartics promote soft to watery stool with cramping. Purgatives promote watery stool with cramping. Some medications’ action as laxatives or cathartics depends on the dose.
Osmotic laxatives work by:
Pulling water into the colon increasing bulk in feces which stimulates peristalsis.
Bisacodyl (Dulcolax), senna, and castor oil are which type of laxative?
Stimulants
Stimulant laxatives work by:
Increasing peristalsis by irritating sensory nerve endings in the intestinal mucosa.
Metamucil, Miralax, and Fibercon are which type of laxative?
Bulk-forming
True or False: It is important to drink a lot of fluid when taking bulk-forming laxatives.
True. They can solidify in the GI and cause an intestinal obstruction.
Lubiprostone (Amitiza) is what type of laxative?
Chloride channel activator
How is Lubiprostone (Amitiza) used?
It is used for idiopathic constipation in adults.
Contraindications for Laxative use include:
Undiagnosed abdominal pain
Inflammatory disorders of the GI tract
Spastic colon
Bowel obstruction
Pregnancy
