GI pharmacology Flashcards
what is the differential of postpandial epigastric pain
pancreatitis
PUD
gallstones
IBS
food intolerance
celiacs
GERD
crohns disease
constipation
Gastroesophageal malignancy
=
what are the key substances involved in gastric acid secretion?
Histamine
Gastrin
ACh
what conditions are treated with acid suppression drugs
list 4
GERD
PUD
gastritis
zollinger-ellison syndrome
what is zollinger-ellison syndrome
rare gastric dx that causes excess gastric acid secretion
what is the most common cause of PUD
H. Pylori infection
t/f: excess alochol consuption causes indirect injurty to mucosal cells, impairing mucus secretion
False
alcohol causes direct injury to mucosal cells, impairing mucus secretion. Low ethonal content such as beer/wine stimulate production of gastric acid- increasing risk of gastritis
t/f: zollinger-ellison syndrome is a commmon condition caused by gastrin-secreting tumors of the esophagus (Barret esophagus) known as gatrinomas.
FAlSE: it is a rare conditiont caused by gastrin secreting tumors of the pancrea of duodenum known as gastrinomas. More than 60% are malignant.
Gastrinomas secrete excessive amounts of gastrin, which bind to parietal cells in the stomach, resulting in hypersecretion of acid
what are the most commonly used acid suppressants
PPI, H2 antagonists, antacids
what is the mechanism of PPI
irreversibly bind and impair the action of H+/K+ATPase in sstomach parietal cells to reduce acid secretion
what is the mechanism of action of H2 blockers?
block histamine H2 receptors on parietal cells
T/F: antacids are weak bases that directly neutralize and reduce acid secretion in the stomach
TRUE
they don’t reduce acid secretion, just neutralize it
HCL is a strong acid (gets rid of all of its H+)
Gastric ulcers are usually located in the lesser curvature of the stomach. What would make this location a dangerous place for an ulcer?
it can lead to bleeding from L gastric artery
DW is a 58 year old woman you are seeing in the oncology outpatient. DW has breast cancer and chronic pain secondary to bony metasases. Her pain is well controlled on non-steroidal anti-inflammatory drugs and low dose opions. “i can deal with the pain, but i dont want anymore meds for that. Im having a hard time moving my bowels. I already tried magnesium citrate, fiber, stool softeners, even nasty castor oil. Nothing worked. Even lactulose didn’t work and that works for almost everyone.”
Is there anything else I can try?”
What is causing the constipation and how can you treat it?
Cause: Opiods
Treat: laxatives
what are the classes of laxatives
Bulf forming
stool surfactant (softeners)
osmotic
stimulant (cathartics)
what common food ascts as a bulk-forming laxative?
Bran
absorbs water int the lumen to distend the intestine and trigger peristalsis
what are some of the adverse effects of metoclopramide
- restlessness
- fatigue
- sdystonia
- extrapyramidal symptoms
- mental depression
- **tardive dyskinesia **
- parkinsonian
*** neuroleptic malignant syndrome **
what is neuroleptic malignant syndrome
Where does area postrema (vomiting center) receive input from
- nucleus tractus solitarius
- GI tract via vagus nerve
- Vestibular system
- CNS
Receptors
Muscarinic (M1)
Histamine (H1)
Nueokinin (NK-1)
Dopamine (D2)
Seratonin (5-HT)
what is a major stimulus of acid secretion
histamine
PPI’s are first line for
- Gerd
- PUD
- Gastritis
- Zollinger-ellison
when are H2 blockers used?
in pts with poor response to PPIs
What does bismuth and sucralfate do?
Physically provide a barrier to ulcerss and promote mucosal secretion
common side effects of bismuth and sucralfate
black stools (mistaken for melana a lot)
what is Misoprostol? what is it used for?
PGE1 analog
Use: for prevention of NSAID induced peptic ulcers
when should misoprostol never be prescribed
as an acid suppressant for women of childbearing age because it is an abortifacient
what is the risk of longterm PPI use
- C diff
- pneumonia
- fractures
- osteoporosis
- hypomagnesemia
what h2 blocker is not safe?
cimitidine.
what is the mc effect of famatodine
headache
when are laxatives useful
acute and chronic constipation, opiate induced constipation and IBS-c
when are antiemetics used?
acute vomiting, chemotherapy induced vomiting, even vestibular motion sickness
Antidiarrheals commonly used for
chronic diarrhea, acute bacterial or viral gastroenteritis, IBS_D ileostomy related diarrhea
