Flashcards in Lower GI Pharmacology Deck (25):
CTZ (in the context of vomiting) stands for ____________.
chemoreceptor trigger zone
The output vomiting center is in the ____________.
What drugs are good for treating the nausea and vomiting induced by chemotherapy?
Ondansetron and the other 5HT3 blockers
Other than diphenhydramine, what are two first-generation antihistamines?
You order an antiemetic for a cancer patient receiving 5-fluorouracil. Her BP drops afterward, and you're reconsidering your order. What drug did you give her?
Prochlorperazine (which has some alpha-1 blockade)
Which laxative most closely approximates the physiologic mechanism of stool passage?
Psyllium (Metamucil) – a bulk-forming agent that induces peristalsis
How do the osmotic laxatives work? What are some osmotic laxatives?
They pull water into the colonic lumen, and thus stimulate peristalsis.
Milk of magnesia
Polyethylene glycol (PEG)
Lactulose (which gets metabolized by colonic bacteria into disaccharides that then pull water into the lumen)
Bisacodyl, castor oil, and senna are examples of _____________.
irritant laxatives that stimulate peristalsis
True or false: docusate (Colace) is the preferred treatment for CV patients with constipation.
False. It can prevent constipation in pregnant women, CV patients, and hernia patients, but it is not a curative agent for constipation.
True or false: magnesium-containing antacids can cause constipation.
All of the magnesium-containing laxatives work by ____________.
What is EHEC?
Enterohemorrhagic Escherichia coli
What is the mechanism of ondansetron?
It blocks 5HT3 serotonin receptors in the CTZ, solitary nucleus, and visceral afferents.
The most serious side effect of 5HT3 antagonists is ____________.
One example of a class III controlled anti-emetic that can lead to euphoria is ____________.
What is one of the biggest concerns with overuse of osmotic laxatives?
You just ordered a medication that gets activated by colonic bacteria and increases osmolarity. What is it?
___________ is often given with atropine, called Lomotil.
Diphenoxylate (a partial opioid agonist)
Low-dose tricyclic antidepressants are given to those with ______________.
irritable bowel syndrome
How does tegaserod work?
It stimulates 5HT4 receptors, leading to peristalsis.
A woman with nausea and vomiting comes to your office. She is in her first trimester. What drug can she take for the nausea and vomiting?
First: pyridoxine and H1 antagonist
Second: add D2 antagonist
Finally (for life-threatening dehydration): 5HT3 antagonist
Which cardiac medication can cause diarrhea?
True or false: activated charcoal can absorb drugs given IV.
____________ is useful in treating constipation and diarrhea.