GI Drugs Flashcards
Drugs acting on the GI system fall into what 5 categories?
Appetite stimulant Inducer/suppressor of emesis Anti-ulcer Increase/decrease GI motility Pancreas and liver
Where is the appetite and satiety center?
Hypothalamus
What are endogenous inhibitors of appetite?
Serotonin
Cholecystokinin
Glucagon-like peptide
Leptin
What are endogenous stimulants of appetite ?
GABA
Ghrelin
Dopamine
Norepinephrine
How does GABA stimulate appetite
By inhibiting the satiety center
What GABA agonists can be used to simulate appetite?
Benzodiazepine (Diazepam, midazolam)
Propofol
What species are benzodiazepines more useful for stimulating appetite?
Cats
What is the most common side effect of benzodiazepines as a appetite stimulant?
Sedation
How do I administer diazepam and midazolam ?
Diazepam -IV
Midazolam -IV or IM
What benzodiazepine can be given PO to cats?
Oxazepam
NOT diazepam-> hepatotoxicity
What drug is an agonist at the ghrelin receptor?
Capromorelin -> increases appetite
Capormorelin is labeled for _______
Dog
What is the MOA of cyproheptadine and mirtazapine?
Serotonin and histamine antagonist -> inhibit satiety center by blocking 5-HT receptor
What is the most common side effect of cyproheptadine?
Sedation
Cyproheptadine is more effective in __________ and mirtazapine is more effective in _________
Cat;dog
T/F: Cats have more A2 and 5-HT receptors than dogs, but have fewer D2 and H1
True
What peripheral emetic works by directly irritating the oropharynx/GI lining
Hydrogen peroxide 3%
Why can hydrogen peroxide not be used as an emetic in cats?
Hemorrhagic gastritis
What is the MOA of apomorphine ?
stimulates D2 receptors -> emesis
Oops.. i have accidentally overdosed a dog with apomorphine? What should i do?
Overdose can cause respiratory depression -> reverse with naloxone
What is my emetic of choice in the cats? What is the MOA?
Xylazine or Dexmedatomidine
A2-agonist (cats have more A2 receptors than dogs)
What are the 3 most common emetics?
Maroptiant
Metoclopramide
Ondasetron
What is the MOA of maropitant citrate?
NK1 receptor -> block substance P and reduces its contribution to vomiting (central at CRTZ and peripherally at GI tract)
What is the purpose of substance P
Integration of pain, stress, anxiety, and vomiting
What are precautions to using maropitant
Injection stings
Bone marrow suppression with high doses in young dogs
What is the MOA of metoclopramide?
Dopamine antagonist (also 5-HT) -> inhibit vomiting at CRTZ
Higher doses prokinetic
What is the MOA of ondasetron ?
Serotonin (5-HT) antagonist centrally and peripherally -> inhibit vomiting at CRTZ and in GI tract
What two anti-emetics have activity both centrally and peripherally
Maropitant
Ondasetron