GI pharm Flashcards
GERD and PUD
H2 receptor antagonists
PPI
mucosal protectants
antacids
antiemetics
increase protective factors
antacids
sucralfate
decrease aggressive factors
H. pylori
target gastric acid secretion: H2 blockers and PPI (parietal cells)
H. pylori tm
several abx and gastric acid I
combo therapy to minimize resistance (likes acidic env and most abx dont thrive well there)
need confirmed case before treating bc resistance
10-14 days, adherence not great bc v expensive and up to 12 pills/day
cimetidine
famotidine
h2 receptor antagonists
moa: block h2 receptors in stomach, reduce gastric acid secretion 60-70%, increases stomach pH
PO, IV at least 1 hr apart from antacids, OTC
I: GERD, PUD, ulcer prophylaxis - asp pna, heartburn/dyspepsia
h2 receptor antagonists: SE
well tolerates, CNS effects in elderly, slight increased risk of pna in elderly
interactions: inhibit cyp450 (cimetidine, thats why famotidine is used 1st line)
can increase warfarin, phenytoin, theophylline bc cyp450 I (esp cimetidine)
give IV slowly to avoid bradycardia
PPIs
omeprazole
patopracole
esomeprazole
moa: bind PP, inhibit H/K ATPase enzyme system (proton pump), irreversibly inhibits secretions of HCl - primary driver for stomach acid secretion
more effective than H2RA
I: short term treatment of PUD and GERD
PPI SE
short = safe
long (years) = increased risk of pna, bone loss/hip fracture, stomach cancer, benefits outweigh risks for most
few interactions
mucosal protectant
sucralfate
sucrose base, aluminum hydroxide
moa: alters when exposed to gastric acid, sticky thick gel -> protective barrier
I: duodenal ulcers, gastric ulcers, chronic gastritis
PO - tablet or suspension, take before you eat
sucralfate: SE
no major
may cause C
decrease drug abs, PO take 2 hrs apart
antacids: SE
Al and Ca based = c
Mg based = d
Mg + Al = balanced
acid rebound
chelation, altered gastric abs of many drugs (separate by 2hr)
antacids
moa: neutralize acid by approximately 50%
I: PUD (heal), GERD (s), stress ulcers (prophyl), heartburn and indigestion (for some)
antiemetics
serotonin blockers
antihistamines
anticholinergics
dopamine antagonists
prokinetics
ondanestron
serotonin blocker
moa: block serotonin receptors in chemoreceptor trigger zone in brain and in afferent vagal nerves in stomach and SI
PO or IV
I: n/v, esp in chemo/radiation
ondanestron: SE
common
mild HA, d, dizzy, c
serotonin S
be aware of other drugs that affect serotonin (SSRI, SNRI, TCA, MAOIs, buspirone, tramadol)