GI III Flashcards
What is the MOA of tegaserod?
Partial agonist that simulates 5HT-4 receptors in the GI tract, to increase ACh, and thus gastric motility
What is the MOA of lubiprostone?
Prostaglandin derivative, the activates CIC2 Cl channels to increase Cl in the GI lumen
What is the MOA of methylnaltrexone?
Mu-opioid antagonist
What is the MOA of alvimopan?
Mu-opioid receptor antagonist
What are the adverse effects of lubiprostone?
n/v/d
What are the adverse effects of methylnaltrexone?
Abdominal pain
n/v/d
What are the adverse effects of alvimopan
abdominal pain
n/v/d
What are the two mu-opioid receptor antagonists?
Methylnaltrexone
Alvimopan
How do the opioid antidiarrheal agents work?
Agonists to opioid receptor cannot cross the blood/brain barrier, but will cause decreased GI motility
How are opioid antidiarrheal agents administered?
orally
What is the MOA of bismuth subsalicylate as an antidiarrheal agent? (2)
inhibition of prostaglandin synthesis in the intestines
Absorb bacterial toxins
What is the difference between bismuth subsalicylate’s action in the stomach, vs in the intestines?
Stomach = inhibit prostaglandin synthesis
Intestines = stimulate
What is the MOA of bile salt binding resins as an antidiarrheal?
Disrupt hydrostatic pressure that bile salts exert (these are used when there is too much bile salt secretion)
What is the MOA of octreotide?
Agonist to the somatostatin receptor which inhibits gut motility
What type of molecule is octreotide? What does this mean in terms of administration?
Polypeptide
Must be given IV or SQ
What type of drug is loperamide?
Opioid agonist (antidiarrheal)
What type of drug is Diphenoxylate?
Opioid agonist
antidiarrheal
What type of drug is cholestyramine?
Binds bile acids and bile salts (antidiarrheal)
What type of drug is octreotide?
Somatostatin receptor agonist (antidiarrheal)
What are the adverse effecs of loperamide?
Constipation
What are the adverse effects of diphenoxylate?
Atropine effects
What are the adverse effects of bismuth subsalicylate?
Salicylate toxicity
What are the adverse effects of cholestyramine?
Impaired fat absorption
Fecal impaction
What are the adverse effects of octreotide?
Impaired pancreatic secretion
Decreased gallbladder contraction
What is the MOA of ondansetron?
5HT3 antagonist (antiemetic)
What is the MOA of scopolamine?
M1 antagonist (antiemetic)
What is the MOA of metoclopramide?
D2 antagonist (antiemetic)
What is the MOA of dimenhydrinate? Use?
H1 antagonist (antiemetic) Motion sickness
What is the MOA of aprepitant?
NK1 antagonist (antiemetic)
What is the MOA of prochlorperazine?
M1 D2 H1 antagonist (antiemetic)
What are the adverse effects of ondansetron?
HA
Dizziness
constipation
What are the adverse effects of scopolamine?
Antimuscarinic effects
What are the adverse effects with metoclopramide?
Parkinsonian symptoms
What are the adverse effects of dimenhydrinate?
Drowsiness
What are the adverse effects of aprepitant?
Fatigue
Dizziness
CYP3A4 interactions
What are the adverse effects of prochlorperazine?
Drowsiness
Anticholinergic
What is the role of GABA in the brain?
Inhibitory neurotransmitter
What is the MOA of lorazepam?
GABA agonist
What is the MOA of nabilon?
Cannabinoid agonist
What is the MOA of dexamethasone?
Glucocorticoid antagonist
What are the adverse effects of lorazepam?
Drowsiness
What are the adverse effects of nabilone?
Dysphoria
Sedation
What are the adverse effects of dexamethasone?
Weight gain/ water retention
What is IBS?
idiopathic chronic relapsing disorder, characterized by abdominal discomfort, with diarrhea, constipation, or both
What is the cause of IBS?
uncertain etiology
What is the drug of choice for treating diarrhea due to IBS?
Loperamide
What is the drug type of choice for treating constipation due to IBS?
osmotic laxatives
What are the drugs of choice for treating pain due to IBS?
antidepressants
Antimuscarinics
What is the MOA that tricyclic antidepressant relieve pain from IBS?
Block signalling from the GI neurons
What are the receptors on the neurons that control gastric motility?
5HT-4
What are the receptors on the neurons that transmit pain from the GI tract to the brain?
5HT-3
What is the MOA of alosetron?
Blocks 5HT-3 receptors on the gut wall to reduce pain
Would you want to stimulate or inhibit the 5HT-4 receptors to induce gastric motility
stimulate
Would you want to stimulate or inhibit the 5HT-3 receptors to reduce pain from the gut
inhibit
What are the very rare, but serious side effects of tegaserod?
MI
What are the side effects of alosetron?
ischemic colitis
Is tegaserod an antagonist, or agonist?
Partial agonist
Is alosetron an antagonist, or agonist?
antagonist
What is IBD? What are the two types?
Inflammatory bowel disease
Crohn’s disease
Ulcerative colitis
What is crohn’s disease?
Idiopathic inflammatory disorder that affects any part of the GI tract
What is ulcerative colitis?
a chronic inflammatory disease that causes ulceration of the colonic mucosa
Which can affect any part of the GI tract, and which is limited to the mucosa of the GI tract: crohn’s disease, or ulcerative colitis?
Crohns = anywhere
What is the MOA of aminosalicylates (ASA)?
Inhibit COX production of prostaglandins, interleukin and NF-kappa B
What is the MOA of glucocorticoids?
Suppression of multiple inflammatory processes
What is the MOA of antimetabolites?
Inhibition of immune cell proliferation
What is the MOA of anti-TNFalpha therapy?
Inhibit TNF-alpha mediated immune response
True or false: aminosalicylates will not work if absorbed from the GI tract?
True–need to work topically
What type of drug is sulfasalzine?
ASA
IBD
What type of drug is mesalamine? What can it be used for?
ASA
IBD
What is the MOA of 6-mercaptopurine?
Inhibit purine synthesis (inhibit immune response for IBD)
What is methotrexate used for?
Inhibits DHFR resulting in impaired cellular proliferation
inhibit immune response for IBD
What is the MOA azathioprine?
Inhibits purine synthesis (inhibit immune response for IBD)
What is the MOA of infliximab?
TNFalpha monoclonal antibody
Binds to TNF alpha, and inhibits immune reponse
When do you start to use antimetabolites in IBD?
When it is moderate or worse
When are steroids an option for IBD?
Active inflamation
What is scolpoamine used for? MOA?
Motion sickness by blocking M1 receptor