Pharm- GI Flashcards
What do PPIs end in? H2 antagonists?
- prazoles
- tidines
MOA for PPIs?
inhibit H+/K+ ATPase on parietal cells thus reducing acid secretion
MOA for H2 antagonists?
block H2 receptors on parietal cells to reduce acid secretion
Antacids are weak ___ that ____ gastric acid
bases
neutralize
MOA of antibiotics
inhibit protein synthesis and disrupt cell wall thus eradicate bacteria
What are the mucosal defenders?
bismuth subsalicylate
sucralfate
MOA for bismuth subsaliculate
coating GI wall, stimulate secretion of PGs, mucus, and bicarbonate, antimicrobial action
MOA for sucralfate
coating GI wall, pepsin inhibitor, stimulate secretion of PGs and bicarbonate
The first line drugs to treat peptic ulcer and severe GERD. Also used for gastric hypersecretion-associated gastrinoma
PPIs
Less potent than PPIs but with relatively rapid onset of action
H2 antagonists
Provide short term relief of symptoms. Can lead to constipation with ____ or diarrhea with ____. Can also cause altered electrolyte balance.
antacids
constipation- aluminum
diarrhea- magnesium
Used to treat H. pylori infection-induced peptic ulcer
antibiotics
Can be combined with antibiotics and H2 blocker or PPI. Used to treat H. pylori peptic ulcer or to prevent traveler’s diarrhea. Can also prevent stress gastritis and treat bile reflux gastropathy and oral mucositis.
mucosal defenders: Bismuth subsalicylate and Sucralfate
Long term use of these reduce B12, Mg2+ and Ca2+ levels and increase risk of infection.
PPIs
What drug can cause side effects in CNS and endocrine system (an H2 antagonist)
Cimetidine
What are the drugs used to treat peptic ulcer?
PPIs, H2 antagonists, antacids, antibiotics, and mucosal defenders
What do 5-HT3 receptor antagonists end in?
-setrons
What do NK1 receptor blockers end in?
-pitant
What are the D2 receptor blockers?
Metoclopramide
Prochlorperazine
Droperidol
What are the H1 antagonists?
Diphenhydrazine
Meclizine
Doxylamine
What is the M1 receptor antagonist?
Scopolamine
MOA for 5-HT3 receptor antagonists?
block both central and peripheral 5-HT3 receptors
MOA for NK1 receptor blockers?
block central NK1 receptors
MOA for D2 receptor blockers?
block central D2 or D2 and M receptors
MOA for Benzodiazepines? Which one did we learn about?
enhance GABA’s effect on chloride ion conductance
Lorazepam
MOA for H1 antagonists?
block central and vestibular H1 receptors
MOA for M1 receptor antagonists?
block vestibular M1 receptors
MOA for synthetic cannabinoids?
not clear, blocking CM and 5-HT3 receptors?
When combined with corticosteroid, this is the most effective treatment for prevention of acute severe vomiting caused by chemotherapy. Also used to treat radiation and postoperative nausea and vomiting.
5-HT3 receptor antagonists
-setrons
Major side effects for 5-HT3 receptor antagonists?
HA, constipation, dizziness, prolonged QT interval
When combined with corticosteroid, this is used to treat delayed chemotherapy-induced vomiting
NK1 receptor blocker
-pitant
What two things combined with a corticosteroid prevent both acute and delayed chemotherapy-induced vomiting?
5-HT3 receptor antagonist and NK1 receptor blocker
Major side effects for NK1 receptor blockers?
fatigue, asthenia (weakness), and hiccups
- Used for radiation, chemotherapy, and infection-induced nausea and vomiting. 2. Used for general emesis. 3. Used for postoperative N/V and sedation.
D2 receptor blockers
- Metoclopramide
- Prochlorperazine
- Droperidol
Major side effects of D2 receptor blockers?
extrapyramidal effects
Droperidol- prolonged QT interval
Used for anticipatory emesis
Benzodiazepines
-Lorazepam
- Used for chemotherapy-induced vomiting. 2. Used for motion sickness. 3. ______ + pyridoxine: pregnancy-related emesis.
H2 antagonists
- Diphenhydrazine
- Meclizine
- Doxylamine
Used for the prevention of motion sickness, comes in transdermal patch
M1 receptor antagonist
-Scopolamine
Major side effects for M1 receptor antagonists?
dry mouth, throat, and nasal passages
Used for chemotherapy-induced emesis and produces cannabinoids-like side effects.
Synthetic cannabinoids
What are the antiemetic drugs?
5-HT3 receptor antagonists
NK1 receptor blockers
D2 receptor blockers
Benzodiazepines
H1 antagonists
M1 receptor antagonist
Synthetic cannabinoids
MOA for Opioids?
- Stimulated μ receptors on enteric neurons.
2. Inhibit presynaptic cholinergic action
What is used to treat all forms of chronic diarrhea?
Opioids
What are the Adsorbents?
- Kaolin and Pectin
- Bismuth subsalicylate
- Bile salt-binding resins
MOA for Adsorbents?
Kaolin and Pectin AND Bismuth subsalicylate bind to bacteria, toxin, and fluid
Bile salt-binding resins bind to bile acid
What is used to treat acute diarrhea in children?
Kaolin and Pectin (adsorbents)
What is used to treat Traveler’s diarrhea?
Bismuth subsalicylate (adsorbents)
What is used to treat bile malabsorption-caused diarrhea?
Bile salt-binding resins (adsorbents)
MOA for synthetic somatostatin
Inhibits the secretion of numerous hormones and transmitters leading to reduced intestinal fluid secretion and decreased gastrointestinal motility.
What is used to treat diarrhea caused by endocrine tumor, vagotomy or dumping syndrome, short bowel syndrome or AIDS?
synthetic somatostatin
Major side effects for synthetic somatostatin?
- lipid-soluble vitamin deficiency
- gallstones
- GI discomfort
- endocrine dysfunction
MOA for chloride channel inhibitor?
inhibit chloride secretion to intestinal lumen
What is used to treat diarrhea caused by antiretroviral therapy?
chloride channel inhibitor
Major side effects of chloride channel inhibitors?
URI, flatulence, and increased bilirubin
What are the antidiarrheals?
Opioids
Adsorbents
Synthetic somatostatin
Chloride channel inhibitor
MOA for prokinetic agents (D2 receptor antagonist)?
peripheral and central
peripheral- increase gastro-esophageal peristalsis and lower esophageal sphincter pressure
central- block D2 receptors in CTZ
What are prokinetic agents used for?
gastroparesis
N/V
Major side effects for prokinetic receptor antagonists?
extrapyramidal symptoms
MOA for bulk-forming laxatives? Clinical use? Major side effect?
Absorb water into the fiber leading to increased fecal volume, thus promoting peristalsis and bowel evacuation
prevent constipation
over-dried stools
MOA for stool surfactant agents? Clinical use? Major side effect?
permit water and lipids to penetrate feces or lubricate stool
prevent constipation in patients who should avoid strain
lipid pneumonitis due to aspiration; longer term use can lead to malabsorption of lipid-soluble vitamins
MOA for osmotic laxatives? Clinical use? Major side effect?
draw water into intestine and colon, increase fecal fluid, and stimulate colonic peristalsis
Can be used to treat acute constipation or prevention of chronic constipation OR bowel prepration
flatus, cramps, water and electrolyte loss
MOA for stimulant laxatives? Clinical use? Major side effect?
stimulate smooth muscle contraction, increase colonic electrolyte and fluid secretion
same as osmotic laxatives but more potent
severe fatus, cramps, water and electrolyte loss
MOA for chloride channel activators? Clinical use? Major side effect?
stimulate type 2 chloride channel in small intestine thus increase chloride-rich fluid secretion
chronic constipation
nausea
MOA for opioid receptor antagonists? Clinical use? Major side effect?
block intestinal μ receptors leading to increased intestine motility
opioid-induced constipation
alvimopan: cardiac toxicity
Mild IBS with pain/bloating
treat with diet
Mild IBS that is constipation predominant
treat with diet and fiber
Mild IBS that is diarrhea predominant
treat with diet and Loperamide (eluxadoline)
Moderate to severe IBS with pain/bloating
treat wtih anticholinergics, rifaximin, antidepressants
Moderate to severe IBS that is constipation predominant
treat with laxatives, lubiprostone, antidepressants (SSRIs)
Moderate to severe IBS that is diarrhea predominant
treat with Loperamide (eluxadoline), antidepressants (TCAs), Rifaximin, Alosetron
