GI drugs Flashcards
What is the MOA of Bismuth?
Two MOAs:
1) Disrupts cell wall, prevents adhesion, inhibits urease
2) Coats ulcer, stimulates PGE, Mucus and Bicarb release
What are three regimens for PUD treatment?
1) PPI + Amoxacillin followed by Clarithromycin and Tinidazole
2) PPI + Tetracyclin+ metronidazole + ciprofloxacin
3) PPI + Amoxacillin + rifabutin +ciprofloxacin
1st line treatment for GERD?
Lifestyle modification
2nd line treatment for GERD?
H2 blockers
3rd line treatment for GERD?
PPIs, esomeprazone
Name PPIs
Esomeprazole/
Omeprazole, Lansoprazole, Pantoprazole, Rabeprazole
What is the MOA of PPIs? (Esomeprazole/
Omeprazole, Lansoprazole, Pantoprazole, Rabeprazole)
Irreversibly inhibit H/K ATPase
Name common antacids
Aluminum hydroxide, calcium carbonate, magnesium hydroxide, sodium bicarbonate
Name AEs of aluminum hydroxide
Constipation, decreased PO4 absorption (osteomalacia)
Name AEs of Magnesium hydroxide
Osmotic diarrhea
In pts with renal insufficiency –> hypermagnesemia –> cardiotoxicity
Name AE of calcium carbonate
Metabolic alkalosis when systemically absorbed
Hypercalcemia if taken w/ dairy products
Name AEs of sodium bicarbonate
Systemically absorbed: metabolic alkalosis, hypercalcemia
What are AEs of PPI use?
ECL hyperplasia due to decreased negative feedback of gastrin from somatostatin
What are CCK effects on gastric mucosa?
Increased pepsinogen (chief cell), increased somatostatin (D cell)
What are Gastrin effects on Gastric mucosa?
Increased acid secretion (direct) Increased histamine release (ECL cell) Increased pepsinogen (chief cell) Increased growht Decreased somatostatin (D cell)
Name H2 blockers?
Cimetidine, Famotidine, Nizatine, Ranitidine
What is the MOA of H2 blockers? (Cimetidine, Famotidine, Nizatine, Ranitidine)
competitive H2 antagonists that decrease all forms of gastric acid secretion
What do H2 blockers compete with for elimination?
weak bases (i.e. metronidazole)
What are AEs of cimetidine?
Inhbitor of CYP450 Androgenic effects (gynecomastia, galactorrhea)
What is the MOA of misoprostol?
PGE1 analog
Used to treat NSAID-induced ulcers- reverses action of NSAIDs at ulcer
AEs of misoprostol?
Diarrhea and severe nausea
Stimulate uterine contractions (abortafactant)
MOA of sucralfate
sucrose sulfate aluminum hydroxide complex that attaches to the basement membrane of the ulcer
May stimulate mucosal PGE and bicarb secretion
What are the pharmacokinetics of sucralfate?
Requires an acidic environment to be activated
What are AEs of sucralfate?
constipation due to aluminum salt
may bind to other meds decreasing absorption
What is the MOA of bismuth subsalicylate?
Bismuth: stimulate PG release
Disrupts cell wall, prevents adhesion, inhibits urease
AEs of bismuth subsalicylate?
Blackening of stool and tongue
High doses of subsalicylate may lead to salicylate toxicity: vomiting, tinnitus, metabolic acidosis/alkalosis
MOA of pancrelipase?
Enriched extract of hog pancreatic enzymes to supplement a pt’s lack of
AE of pancrelipase?
Diarrhea, abdominal pain
Hyperuricosuria –> renal stone
MOA of orlistat?
lipase inhibitor- pancreatic and gastric lipase and phospholipase A2, decreasing digestion and absorption of fat
AEs of orlistat?
Decreased fat absorption –> increased flatus, fecal urgency
Decreased fat soluble vitamins ADEK
MOA of ursodiol?
Secondary acid ursodeoxycholic acid, conjugates w/ glycine and taurine in liver decreasing CE in bile decreasing CE gallstones
Action of CCK on pancreatic acini
Increase enzyme secretion in intestinal phase
Increase growth
Action of Gastrin on Pancreatic acini
Increase enzyme secretion (gastric phase)
What is the MOA of lubipristone?
CIC-2 activator, increase Cl excretion, retain H2O in lumen
What are AEs of Lubipristone?
Increased fetal loss, diarrhea in infants (found in milk)
What is the MOA of Linaclotide?
GC-C activator, increasing cGMP, activationg CFTR channel
What are AEs of linaclotide?
Increased maternal death in animals, mortality of juvenile mice
What is MOA of Crofelemer?
voltage-independent inhibition of CFTR, decreasing Cl- secretion
What is AE of crofelemer?
Constipation
What is MOA of octreotide?
Somatostatin analogue, decreases 5HT stimulation, decrease hormone release.
Low dose increases motility, High does decreases motility
What are the uses for octreotide?
treatment of tumors, severe diarrhea due to dumping syndrome, short bowel syndrome, vagotomy
what are AEs of octreotide?
Decrease in GI motility, impaired pancreatic secretion
What is the use of lactulose?
Decreases plasma ammonia levels due to alkalinizing lumen,
also increases H2O retention due to osmotic forces
What are the AEs of lactulose?
When metabolized by gut bacteria, severe cramps and flatulence
What are MOA of sodium phosphate?
Increase osmotic pressure in lumen, creating looser stools
What are AEs of sodium phosphate?
Intracellular volume depletion and electrolyte imbalances
What are MOA od cholestyramine and colestipol?
Decrease reabsorption of bile salts
What are AEs of cholestyramine and colestipol?
Bloating, flatulence, constipation, fecal impaction
What is MOA of Alosetron?
5HT3 antagonist, decreasing motility (decreasing afferent stimulation)
What are AE of alosetron?
Constipation in 30% of patients
ischemic cholitis.
What are MOA of tegaserod and cisapride?
Activation of 5HT4 presynaptic receptors, increasing gastric motility
what are AEs of tegaserod and cisapride?
Arrhythmias, long QT
What is the MOA of Diphenoxylate and Loparimide?
u-agonists, decrease motility and secretion
What are AEs of diphenoxylate and loparimide?
Constipation, abdominal cramps, TOXIC MEGACOLON
They can make people high, too
What is MOA of Alvimopan, methylnaloxone?
u-receptor antagonists; increase gastric motility
What are AEs of alvimopam and methynaloxone?
Alvimopam: increased risk of MI
What is MOA of domperidone and metaclopramide?
Inhibits dopamine inhibition, increasing ACh in gut, increasing motility
Whar are AEs of domperidone and metaclopramide?
Domperidone: Sudden cardiac death
Metoclopramide: dystonia, parkinsonism, tardive dyskinesia
How do they decrease the risk of abuse with domperidone?
D2 receptor antagonist, Add atropine
