GI Pharmacology Flashcards
upper GI distress drugs that decrease aggressive factors
–treat H. pylori
–H2 blockers
–proton pump inhibitors
upper GI distress drugs that increase protective factors
–antacids
–sucralfate
how to treat H. pylori
–several antibiotics + gastric acid inhibitor
–combination therapy
why combination therapy to treat H. pylori?
–minimize resistance
–H. pylori likes acidic environment
length of Rx for H. pylori
10-14 days
adherence to treatment for H. pylori
about $200 with up to 12 pills
what are two ways drugs target gastric acid production?
–block H2 receptors
–inhibit proton pump
role of histamine
promotes production of gastric acid
role of parietal cell
makes gastric acid
examples of H2 receptor antagonists
–cimetidine (Tagamet)
–famotidine (Pepcid)
MOA of cimetidine/famotidine
–block H2 receptors in the stomach
–reduces gastric acid secretion by 60-70%
–increases stomach pH
route for cimetidine/famotidine
PO, IV
administration tidbit for cimetidine/famotidine
give at least 1 hour apart from antacids
indications for cimetidine/famotidine
–GERD
–PUD
–ulcer prophylaxis
–heartburn/dyspepsia
how does cimetidine/famotidine work for ulcer prophylaxis?
prevents aspiration pneumonia risk
adverse effects of cimetidine/famotidine
–well tolerated
–CNS effects in elderly
–slight increased risk for pneumonia in elderly
interactions of cimetidine/famotidine
–inhibits CYP450 enzymes (older)
–newer generation H2RAs do not have this problem (ex. Pepcid)
safety alert for cimetidine/famotidine
–can increase levels of warfarin, phenytoin, theophylline
–give IV form slowly to avoid bradycardia
examples of proton pump inhibitors (PPIs)
–omeprazole (Prilosec)
–pantoprazole (Protonix)
–esomeprazole magnesium (Nexium)
MOA of omeprazole/pantoprazole/esomeprazole magnesium
–binds to proton pump
–inhibits hydrogen potassium ATPase enzyme system
–irreversibly inhibits secretion of HCl
indications for omeprazole/pantoprazole/esomeprazole magnesium
short term treatment of PUD and GERD
tidbit about omeprazole/pantoprazole/esomeprazole magnesium
more effective than H2RA
adverse effects of omeprazole/pantoprazole/esomeprazole magnesium
short term: relatively safe
long term: increased risk for pneumonia, bone loss/hip fracture, stomach CA
nursing implications for omeprazole/pantoprazole/esomeprazole magnesium
short term use only
example of mucosal protectant
sucralfate (Carafate)
sucralfate (Carafate)
unique drug composed of:
–sucrose-base
–aluminum hydroxide
MOA of sucralfate
–alters when exposed to gastric acid
–sticky, thick gel –> protective barrier
indication of sucralfate
duodenal ulcers, gastric ulcers
route for sucralfate
PO (tablet or suspension)
adverse effects of sucralfate
–no major
–may cause constipation
interactions with sucralfate
–decreased drug absorption
–PO: take 2 hours apart
major bases for antacids
–aluminum
–calcium
–magnesium
–Al+Mg
example of aluminum antacid
amphojel
example of calcium antacid
tums
example of magnesium antacid
milk of magnesia
example of Al+Mg antacid
Maalox, Mylanta
side effect of aluminum antacid
constipation
side effect of calcium antacid
constipation
side effect of magnesium antacid
diarrhea
side effect of Al+Mg antacid
balanced approach
MOA of antacids
neutralizes acid by approximately 50%
indication of antacids
–PUD
–GERD
–stress ulcers
adverse effects of antacids
–diarrhea or constipation
–acid rebound
interactions of antacids
–chelation
–altered gastric absorption of many drugs
example of serotonin blocker
ondansetron (Zofran)
MOA of ondansetron
blocks serotonin receptors in the trigger zone in the brain and in the afferent vagal nerves in the stomach and small intestine
route of ondansetron
PO or IV
use of ondansetron
used to treat N/V (esp. chemo/radiation induced)
adverse reactions of ondansetron
common –> usually mild
–HA
–dizziness
–diarrhea
serious adverse reactions of ondansetron
–serotonin syndrome
drug interactions with ondansetron
–SSRIs
–SNRIs
–TCAs
–MAIs
–buspirone
–tramadol
examples of antihistamines
–dimenhydrinate (Dramamine)
–meclizine (Antivert)
–hydroxyzine (Vistaril)
MOA of dimenhydrinate/meclizine/hydroxyzine
blocks the release of histamine H1 receptors in the inner ear
indications for dimenhydrinate/meclizine/hydroxyzine
treatment of dizziness and nausea –> antiemetic and antivertigo associated with motion sickness
adverse reactions of dimenhydrinate/meclizine/hydroxyzine
–sedation
–drowsiness
–dizziness
–anticholinergic effect
–FALL RISK
example of dopamine antagonists: prokinetic agent
metoclopramide (Reglan)
MOA of metoclopramide
–blocks dopamine receptors
–increases tone of LES
–increases peristalsis in both the stomach and the intestine
indications of metoclopramide
–N/V associated with chemo/radiation/opioids
–GI motility issues
–paralytic ileus
side effects of metoclopramide
–sedation
–extrapyramidal symptoms
–restlessness
–neuroleptic malignant syndrome
extrapyramidal symptoms
–akathisia
–acute dystonia
–Parkinsonism
–Tardive dyskinesia
–Neuroleptic malignant syndrome
akathisia
–may feel restless
–tense
–constant desire to move
acute dystonia
involuntary muscle contractions
Parkinsonism
–muscle tremors
–cogwheel rigidity
–drooling
–shuffling gait
–slow movements
Tardive dyskinesia
–abnormal muscle movements (lip smacking, tongue darting, chewing movements, slow and aimless arm and leg movements)
neuroleptic malignant syndrome
rigid muscles, fever, confusion
what are extrapyramidal symptoms common with?
more common with antipsych meds
examples for diarrhea drugs
–diphenoxylate with atropine (Lomotil)
–loperamide (Immodium)
MOA of diphenoxylate with atropine/loperamide
–decrease intestinal peristalsis
–reduce the intestinal effluent
adverse reactions of diphenoxylate with atropine/loperamide
–drowsiness
–constipation
–falling and driving precautions
–anticholinergic effects
–SERIOUS: cardiac arrest/arrythmias
example of 5-aminosalicylates
sulfasalazine (Azulfidine)
indications of sulfasalazine
mild to moderate IBD
MOA of sulfasalazine
sulfonamide antibiotic that converts the intestine into 5-aminosalicylic acid and sulphapyridine
side effects of sulfasalazine
–nausea
–fever
–rash
–HA
–hematologic disorders
precaution for sulfasalazine
do not give to patients who are allergic to SULFA drugs or who have certain types of anemias
example of DMARDs for IBD
infliximab (Remicade)
DMARD
disease modifying antirheumatic drug
MOA of infliximab
monoclonal antibody which neutralizes TNF-alpha
side effects for infliximab
–immune suppression
–infection
–cancer
–heart failure
–infusion reactions
–neutropenia
additional note about infliximab
often require therapeutic drug monitoring and biomarker monitoring for inflammation
