GIPharm Flashcards
what controls the urge for food seeking, hunger/appetite, and satiety center
Hypothalamus
when is it appropriate to use appetite stimulants?
- when a feeding tube cannot be places
- when underlying cause of anorexia or hyporexia has been removed but patient is still not eating.
what is the MOA of cyproheptadine, and what is it used for?
Cyproheptadine is an apetite stimulant, and is a 5-HT (serotonin) antiagonist that inhibits the satiety center.
what are some adverse affects of giving cyproheptadine, an appetitie stimulant?
- sedation
- anticholenergic effects (dry mucous membranes)
when would you use mirtazapine?
it is used as an appetite stimulants
what is the MOA of mirtazapine
- 5HT (serotonin) antagonist (antinausea effect, increased appetite)
- alpha adrenergic receptor antagonist (increased norepinephrine leading to increased appetite)
- H1 receptors (sedation)
what is the most effective drug we have for appetite stimulant?
mirtazapine
how often is mirtazapine dosed?
dosed every 3 days to reduce the risk of side effects
what is capromorelin used for and what is it’s MOA
it is an appetite stimulant, and is a ghrelin receptor agonist
- only for used in dogs
what is the most effective appetite stimulant for cats?
diazepam
what receptors are found in the CRTZ
▪ Neurokinergic (NK1) ▪ Serotonergic (5HT3) ▪ Adrenergic (a2) ▪ Dopaminergic (D2) ▪ Cholinergic (M1) ▪ Histaminergic (H1)
what receptors are found in the emetic/vomiting center?
▪ Neurokinergic (NK1)
▪ Serotonergic (5HT3)
▪ Adrenergic (a2)
what is apomorphine used for, and how does it work?
it is used as an emetic that stimulates the dopamine (D2) receptors in the CRTZ
what is the drug of choice to cause emesis in cats and it’s MOA
- xylazine
- it is an alpha 2 agonist
T or F
All emetics carry a risk of aspiration pneumonia especially in recumbent, sedated,
or very ill patients
True
what is Metoclopramide used for? and what is it’s MOA
- it is an antiemetic
- serotonin antagonist (works better in dogs than cats)
- promotility agent
I am a NK1 receptor antagonist that inhibits substance P and works directly at the emetic center, and is generally used to treat motion sickness, chemotherapy induced nausea, and other causes neausea.
Maropitant (cerenia)
what is ondansetron used for and what is it’s MOA
it is an antiemetics, that is a serotonin antagonists (much better than metoclopramide)
has to be dosed to 4x’s daily
what are your options for antacids? and what is their MOA
- Aluminum hydroxide (Mylanta)
- Magnesium hydroxide (Milk of Magnesia)
- Calcium Carbonate (Tums)
these do not decrease the acid production, only neutralize it. Tums is the best/safest option.
T or F
the disadvantage of using calcium carbonate is that it can be absorbed systemically and can cause alkalosis
True
what drug options do you have if you need to prescribe a H2 antagonists
- famotidine
- ranitidine
- cimetidine
- nizatidine
what are some advantages and disadvantages of using aluminum hydroxide
advantages is that it is not systemically absorbed, but it will cause drug interactions
what are some advantages and disadvantages of using magnesium hydroxide?
it is more effective than Al hydroxide but can cause diarrhea, drug interactions, and is systemically absorbed
what is cimetidine used for and what is it’s MOA
- it is an H2 antagonist that is the least potent, and shortest acting.
- it inhibits CYP 450 and can affect hepatic blood flow
what is ranitidine used for and what is it’s MOA
- it is an H2 antagonist blocker with intermediate potency
- drug interactions are less likely than with cimetidine
- has prokinetic effects (due to inhibition of AChE
what are the two most potent H2 antagonists?
- famotidine
- nizatidine
what are some side effects of famotidine
- bradycardia
- can cause hemolysis in cats
but does not inhibit CYP 450
what are the H2 antagonists classically used for?
- uremic patients
- mast cell tumors (histamine)
- gastroesophageal reflux
T or F
Famotidine should only be used for a couple days
True
Famotidine only effective at increasing gastric pH for 2 days at high doses
▪Proton pump inhibitors are preferred
if you had to prescribe a proton pump inhibitor what drug options should you choose from?
which is considered the most effective?
- omeprazole (prilosec) given PO
- pantoprazole (protonix) given IV
Should give Omeprazole
what are some drug interactions for Omeprazole
- inhibits CYP 450
and is the oral drug of choice for treating ulcers and esophagitis
what is the IV drug of choice for treating ulcers and esophagitis?
Pantoprazole
- it also has no reported inhibited CYP 450 effects
what is misoprostal used for, and what effects does it have?
it is a mucosal protectant
- inhibits gastric acid secretions
- increases bicarb secreation
- increases mucus secretion
- increases gastric blood flow
what would be a clinical indication for the use of misoprostal
- treatment and prevention of NSAID induced ulcers
what are some adverse effects of using Misoprostal
- GI distress (abdimonal pain, diarrhea, nausea)
- uterine contractions, vaginal bleeding, induction of parturition
- can have a risk to women
what is sucralfate used for and how does it work
mucosal protectant that binds to epithelial cell membranes and protects against HCl, bile and pepsin
what is the net effect of adrenergic receptors
these are sympathetic tone receptors which inhibit motility
what is the net effect of cholinergic receptors
these are parasympathetic receptors which will enhance motility
what is the MOA of metoclopramide
it is a serotonin antagonist that sensitizes the GI smooth muscle to the effects of acetylcholine
what are some clinical uses for metoclopramide
- ileus
- GDV
- delayed gastric emptying
- gastroesophageal reflux
what are some clinical uses for cisapride
cisapride enhances ACh release from intrinsic cholinergic neurons and is used for
- megaesophagus in cats
- gastroesophageal reflux
- delayed gastric emptying
- ileus
- megacolon in cats
why might you not use cisapride for the treatment of megaesophagus in dogs?
the dog esophagus is primarily made of skeletal muscle, which is in contrast to cats.
Cisapride has action on smooth muscle and therefore would not have an effect in dogs.
what condition would your prescribe ranitidine
- ileus
- gastroesophageal reflux
this drug primarily effects the Stomach, but has overall GI effects
what is the MOA of Ranitidine
inhibition of acecholinesterase activity.
Also H2 receptor antagonist.
what is the MOA of Nizatidine
H2 receptor blocker that inhibits acetylcholinesterase activity
what clinical reasons would you use nizatidine
- delayed gastric emptying
- constipation
- pseudo-obstruction of the intestines
- gastroesophageal reflux
T or F
Erythromycin can be used for prokinetic proposes in the distal GI track.
FALSE
Whilt is it true that erythromycin does have prokinetic effects, it is less effective in the distal GI tract due to the lack of motilin receptors
what are some clinical uses for Erythromycin
- delayed gastric emptying
- gastroesophageal reflux
- decreased colonic motility (dogs only)
it is not commonly used in small animals
Although Bethanechol is not typically used for GI motility, what can we use it for?
- used to improve bladder contractility
- potential used in megaesophagus
what are the adverse effects of bethanechol
- bradycardia
- increased gastric acid secretion
- increased pancreatic secretions
- SLUD
what 2 opoids can you for their antidiarrheal effects
- diphenoxylate
- loperamide
what are some adverse reactions for loperamide
it is an opoid what caus- es decreased GI motility
- reactions in dogs with MDR1 mutation
- Dogs - constipation, bload, sedation
- cats - not recommended due to excitation behavior
what is the MOA of laxatives
- they increase hydration of fecal mass
- Lubricate
What type of enema should never be used in cats
Phosphate enemas
under what cercumstances would you prescribe ursodeoxycholic acid
ursodeoxycholic acid or ursodiol is a water soluble bile acid used in
- cholestasis
gallbladder sludge
mucoceles
what is the MOA of ursodiol
- decreases hepatic synthesis and secretion of cholesterol
- increases bile flow
reduces hepatotoxic effects of bile salts
what two drugs can you give to help protect the liver
- S-adenosyle methionine (SAMe)
- Silymarin (milk thistle)
