Gastrointestinal Pharmacology Flashcards
what is the mechanism of action for H2-blockers
○ Competitive block of H2-R on parietal cells
what are the specific agents of H2-blockers
Cimetidine (Tagamet), Ranitidine (Zantac), Famotidine (Pepcid)
what is the therapeutic uses for H2-blockers
ulcers
what is the mechanism of action of anticholinergics
Block of M-receptors on parietal cells
what is the therapeutic use of anticholinergics
ulcers
what is the mechanism of action of PPI
H+, K+-ATPase inhibition
what are the specific agents of PPI
omeprazole and esomeprazole
what are the therapeutic uses of PPI
ulcers
GERD
management of Zollinger-Ellison syndrome
what are the mechanism of action of PGE1 analogues
1) Decreased proton pump activity
2) Increased bicarbonate and mucous secretion
what is the therapeutic use of prostaglandins
prevention of NSAID-induced ulcer/GI bleed
what is the contraindication of PGE1 analogues
pregnancy
what are drugs that decreases motility in the GI
- diphenoxylate-atropine
- loperamide
what is the mechanism of action of diphenoxylate
Opioid receptor agonist - Inhibits ACH release in enteric system at low doses
what is the mechanism of action of atropine
1) Synergistic effect with diphenoxylate to decrease effects of ACH on the gut
2) Anticholinergic side effects discourage abuse potential
loperamide is similar to diphenoxylate-atropine, but without the ?
atrropine
what drugs increases motility
- laxatives
- metoclopramide
- domperidone
- antinausea
what are the 4 main categories of laxatives
○ Bulking agents
○ Osmotic laxatives
○ Chemical stimulants
○ Stool softeners
what are bulking agents
Non-absorbed agents that create bulkier stools and draw water into stools
what does bulkier stool do
stimulates the bowel
what does softer stool do
easier to move
what are osmotics laxatives
Results in an increase in osmotic pressure leading to retention of water in intestine, lumen extension, and increased bowel action
what are chemical stimulants: laxatives
Irritate the gut to induce peristalsis and increase mucous production
what are stool softenenrs: laxatives
Use water or oil to soften stools
examples of stool softeners
mineral oil
sodium docusate
what is the mechanism of action for anti-nausea/vomiting of metoclopramide
block of central D-receptors
what is the mechanism of action for increased motility of metoclopramide
block of peripheral D-receptors (dopamine is inhibited)
what are the therapeutic uses of metoclopramide
- GERD
- Diabetic gastric stasis
- prevention of nausea and vomitting with chemotherapy
what are the adverse effects of metoclopramide
diarhea
hyperprolactinemia
how does hyperprolactinemia happen
blocking dopamine therefore causes increased prolactin
what can be used to stimulate milk production in lactating mothers
domperidone
what are the two drugs for antinausea
- anticholinergics
- D2 blockers
what does anticholinergics do
Block cholinergic transmissions between vestibular and vomiting centers in the CNS
what are the specific agents of anticholinergics
- scopolamine
- promethazine
what are the specific agents of D2-blockers
- metoclopramide
- domperidone
