GI Therapeutic Principles- Summers Lect. 2 Flashcards
Why should we be hesitant to give a patient oral antibiotics for GI disease?
can cause permanent dysbiosis
predisposes to enteropathogenic bacteria
promotes antibiotic resistance
worsens GI signs: vomiting, diarrhea and inappetance
What are some systemic diseases dysbiosis plays a role in?
obesity
chronic kidney disease
type 2 diabetes
When are antibiotics indicated in GI disease?
-parvovirus p w/ neutropenia
-Acute Hemmorhage diarrhea syndrome WITH signs of sepsis
-E. Coli associated granulomatous colitis (based on FISH + colonic tissue sample)
-enteropathogenic bacteria with signs of systemic illness
-very uncommonly - antibiotic- responsive diarrheal trial (after workup, diet trial)
What are some GI cases where antibiotic use is NOT indicated?
-acute diarrhea
-AHDS w/o signs of sepsis
-antibiotic responsive diarrhea trial w/o first doing a feed trial and workup
-chronic large bowel diarrhea w/o work up
-enteropathogenic bacteria in NONCLINICAL cases
What are are therapeutic options for the gut microbiome?
probiotics
pre biotics
fecal transplant
What are the most common bacteria that can be found in probiotics?
Lactic-acid producing
Lactobacillus, enterococcus, streptococcus, bifidobacterium)
When should I consider use of a probiotic in GI disease?
in cases of acute uncomplicated diarrhea
-prevention and tx of stress diarrhea
-prevention of antibiotic-associated GI signs
-As an adjunct therapy for chronic enteropathies
If there is a patient that is presenting with a chronic enteropathy, what probiotic should I prescribe?
A high dose, multi-strain probiotic. (Visbiome)
When do probiotic health benefits end?
once you discontinue use. they do NOT induce changes in the intestinal microbiota or permanently colonize the gut
How long until clients should expect to see a change with probiotics?
1-3 days
If I prescribe a patient an antibiotic, how long should they wait before giving the probiotic?
at least 4 hours
What is a probiotic?
Live microorganisms which when administered in ADEQUATE amounts, confer a health benefit to the host
What is a prebiotic?
NON-digestible fermentable food ingredients (fiber) that promote growth and function of the beneficial bacterial already present in the gut
Are all fibers considered prebiotics?
NO
When classifying fiber, what are the classifications that should be considered?
1- Fermentability: is it readily metabolized by the gut bacteria? (prebiotics)
2.)Solubility
3: Viscosity: thicken in the presence of water
Describe the difference between soluble and insoluble fiber?
soluble fiber: dissolves in water; may soluble fibers are fermentable/
Insoluble. fiber: do NOT dissoolve in water . they are used to bulk and firm the stool or as a bulkin gagent in food to make animals feel full.
Describe the characteristics of Wheat dextrin (Benefiber). Why should you rx a low dose to start?
it is a soluble, non-viscous readily fermented fiber
wheat dextrin can soften stools because of its fermentability
Describe the characteristics of Psyllium Husk Powder (metamucil). Is it a good prebiotic?
it is soluble. viscous/gel forming and non- fermented fiber.
NOT a good prebiotic but is useful because it will help firm up diarrhea no matter the cause.
Why is the gel component of Psyllium husk powder beneficial?
has a stool normalizing effect and the gel is helpful with constipation
What is the starting dosage of Psyllium husk powder in dogs and cats?
Dogs: 1-3 tsp SID
Cats: 1/4 to 1/2 tsp SID
Why is pumpkin not a great option for fiber?
very low in fiber in comparison to psyllium husk powder
What is a fecal microbiota transplant?
administration of a fecal infusion from a healthy individual (donor) to a patient with disease
When is a fecal microbiota transplant helpful?
-In antibiotic associated diarrhea/dysbiosis
-Acute diarrhea
-Clostridium difficile infection
What are recommended selection criteria for canine fecal donors?
Hx, PE, no travel history outside of area, btw age of 1-10, has not been on antibiotics in the last 12 months, etc. normal CBC/Chem
Describe how to administer a Fecal microbiota transplant
Collect enough feces from a donor ( 5g feces/kg of bw). dilute the feces 1:4 in a non-bacteriostatic saline then pass that solution through a sieve. Patient should be fasted and ideally sedated to max retention time of 45 min.
then, measure a red rubber catheter from the top to the rib cage and then administer with a 12-14 g red rubber catheter
Describe a highly digestible, low residue food and GI dz would benefit from this diet
has low amounts of insoluble fiber to promote stomach emptying + is high in complex carbs.
acute gastritis and enteritis
Describe a low-fat food and what species they are used in as well as what GI disorders would benefit
dogs only! cats need fat.
Fat range of 16-22%
tx of acute gastritis enteritis cases, pancreatitis and protein losing enteropathies
In order to compare commercial diets, what should you look at?
Choloric density and %ME
What are the types of elimination diets for animals with food allergies?
Hydrolized, limited ingredient/novel protein and elemental
What is a hydrolized diet?
protein source is broken down into peptides in hopes that the allergen will go undetected by the immune system
most diets achieve peptide size of 7-10 kd which means a type IV delayed cell mediated reactions still possible
What is a limited ingredient/novel protein?
a protein source that the pet has never been exposed to. think exotic
requires a thorough diet history
What is an elemental diet?
protein source that consists of amino acids therefore its super hypoallergenic.
How long should a dematologic elimination diet trial last? What about a GI disease trial?
derm: 8-12 weeks
GI: at least 2 weeks (if no improvement, try another diet)
indications of Proton pump inhibitors
Tx of choice for: increasing gastric pH in dogs + cats with gastric or esophageal ulceration and/or hyperacidity
also helps with the prevention of reflux esophagitis secondary to gastroesophageal reflux
MOA of proton pump inhibitors
irreversibly binds to H+/K+ ATPase pump
(they only targets pumps that are actively recruited so give shortly before or during a meal!)
Drug names of Proton Pump Inhibitors (given po)
-Omeprazole (Prilosec) - q po BID
-Esomeprazole (Nexium) q po BID
What are H-2 Receptor blockers used for and what is their MOA ?
blocks H2 receptors and prevents histamine from binding which prevents the increase of proton pump on the luminal membrane of the parietal cell= decreased acid production
acid suppresant and raises gastric pH
List the names of some H-2 receptor blocker drugs and what their advantage is over PPI
famotidine (p with ulcers)
cimetidine
ranitidine
does not inhibit CYP450 (liver enzyme) like PPIs do but also isn’t as effective
What should I be concerned about in a patient that has been on PPIs for more than 4 weeks?
rebound gastric acid hypersecretion
What is the MOA of Sucralfate?
polymerizes with protein in DAMAGED mucosa in presence of HCl to form viscous, sticky gel like protective layer.
What do we use sucralfate to help tx?
managing esophagitis or gastroduodenal ulceration
can be used for all ACTIVE ulceration/erosion.
What is the MOA of Misoprostol (Cytotec)
synthetic PGE1 analog that binds to the proton pump on the parietal cell and inhibits gastric acid secretion.
it stimulates mucous neck cells which increases production of gastric mucus and bicarbonate;
When do we rx Misoprostol?
NSAID associated ulcers- esp. asparin!
MOA of Maropitant
Neurokinin-1 inhibitor thus inhibitis substance P
there are a lot of NK receptors in areas that mediate vomiting
When do we rx maropitant?
acute vomiting in dogs + cats, to decrease nausea associated with CKD and before and after chemo tx
What is the MOA of a 5HT receptor antagonist?
antagonizes 5HT3 receptors which act on the emetic center - used as a second line anti-emetic after maropitant
What are some drug names of 5HT3 receptor antagonists?
Ondansetron (Zofran)
Dolasetron (Anzemet)
MOA of Metoclopramide (Reglan)
D2 receptor antagonist so it only acts on the D2 receptors in the chemoreceptor trigger zone that act on the emetic center- making it a week antiemetic
it does increase lower esophageal tone
Why isn’t metoclopramide a good anti emetic choice in cats?
because they have few CNS D2 receptors.
What is the MOA of Cisapride (Propulsid)? What effects does it have?
it is a 5-HT receptor antagonist that enhances Ach release at the myenteric plexus
increases motility from stomach to colon; increases LES tone
What are some cases that might benefit from Cisapride (Propulsid)?
megacolon/constipated cats due to its effects on colonic motility
What type of drugs should we be cautious of giving while patients are on Cisapride?
drugs that inhibit P450 because Cisapride is metabolized by CYP450
Why would Cisapride be an ineffective tx for distal esophageal dysmotility in dogs?
All of the esphagus in dogs is striated muscle and Cisapride is a smooth muscle prokinetic! (so is metoclopramide)
What is the MOA of Mirtazapine?
it is a central alpha 2 antagonist (increases norepiniephrine) and is an antagonist of 5-HT3 receptors in the CRTZ
When would it be a good idea to rx Mirtazapine?
When should we be cautious with dosage + why?
prescribe to overcome feed adversion, in chronically ill piatients,
be cautious in kidney/ hepatic dz because it is glucuronidated in the liver and excreted in the kidneys
What is the MOA of Capromorelin (Entyce)?
It is a ghrelin receptor agonist which signals the hypothalamus to stimulate appetite and increase pituitary GH release which increases IGF-1 secretion in the liver
Why should we be cautious when prescribing Capromorelin to brachycephalic patients?
the adverse effect of hypersalivation could potentially cause an obstruction (a.so be careful with diabetic patients)
What is the MOA of Metronidazole (Flagyl)?
antimicrobial w/ broad spectrum activity against anaerobic bacteria and has immunomodulatory and anti-inflammatory properties
When should metronidazole (Flagyl) be prescribed to a patient?
acute hemmorhagic diarrhea WITH SIGNS OF SYSTEMIC ILLNESS (fever, inflammatory leukogram) and giardia
What is the MOA of Tylosin (Tylan)?
Macrolide antibiotic; binds to 50s ribosomal subunit to prevent protein synthesis
What are indications of Tylosin (Tylan)?
antibiotic-responsive enteropathy (think german shepards); small intestinal bacterial overgrowth
What is the MOA of Polyethylene glycol 3350 (Miralax)?
osmostic laxative i.e it draws water into the colon
What are indications for use of Polyethylene glycol 3350?
bowel cleansing prior to colonoscopy in conjunction with electrolytes
also used for management of constipation in cats
What are the types of feeding tubes are available?
-Nasoesophageal or Nasogastric tubes
-esophagostomy tubes
-gastrostomy tubes
-Enterostomy tubes
What are indications of feeding tubes?
-Anorexia or severe hyporexia for more than 3 days (consider the time prior to arriving @ the hospital)
-proactive in patient expected to have difficulty eating (ex. oral surgery)
-severe dysphagia and inability to retain food
What are some contraindications of when to not use a feeding tube?
-Intractable vomiting or regurgitation
-Compromised gag reflex
-severe dysmotility disorders
How do you calculate the amount of food to feed a patient with a feeding tube?
Step 1: Calculate resting energy requirement (RER)
Step 2: Maintenance energy requirement (MER): multiple RER by factor according to disease state (1.2-1.6)
What are the feeding directions for administering nutrients in a feeding tube?
Step 1: start with 25-50% (this is based on duration of anorexia of the p) of RER (divided up between 4-6 bolus feedings throughout the day) or can be given as a CRI in hospital)
Step 2: Gradually increase the amount of feeding each day
How much do patients generally tolerate per tube feeding?
usually 5-10 ml/ kg per feeding
If a patient has had a history of anorexia for over 10 days, what RER should I start with when developing a feeding plan for a patient?
start with 25% RER total per day
If a patient has a history of acute anorexia that has lasted less than seven days, what RER should I start with when developing a feeding plan for a patient?
start with 50% RER total per day
What type of tubes require a liquid diet?
any tube less than 8-10 french
-nasoesophageal tube or nasopgastric tube
-enterostomy tubes
What is a step-by-step approach to assisted feeding case management?
Step 1: Determine a route of assisted feeding
Step 2: Calculate RER
Step 3: Calculate feeding amount for the first day and beyond
Step 4: Determine feeding frequency and kcal per feeding
Step 5: Select a diet based on the patients problem list and determine the kcal/mL
Step 6: Calculate the amount of feeding tube blend to deliver at each feeding (i.e the amount of water you add to the slurry dilutes the cals!)
Step 6: gradually increase caloric intake to meet MER once they are tolerating RER
How long can you use nasoesophageal and nasogastric tubes?
1-10 days; used in hospital
requires a liquid diet, TAKE RADS TO CONFIRM LOCATION before feeding. It MUST be in the esophagus
What are the benefits of a esophagostomy tube?
-can be used in hospital or at home
-requires anesthesia and surgery for placement
-most canned foods can be blenderized and given through the E-tube
-can be used for long-term (years)
-can be removed without sedation or anesthesia
-contraindicated in pets with esophageal disease
What are the two types of gastrostomy tubes?
percutaneous endoscopic gastrostomy (PEG) tubes
-surgically placed gastrotomy tubes
What are some pros and cons of gastrostomy tubes?
Cons: dangerous if removed too early because it needs to adhere to the body wall- if not then peritonitis can occur, requires anesthesia and surgery for placement
Pros: can be used for years if well taken care of
Pets with what conditions may benefit from a gastrostomy tube?
pets with esophageal disease
ex. congenital megaesophagus
When are enterostomy tubes used?
in hospital when the stomach must be bypassed. require a liquid diet bc they are placed directly into the intestine
Patients with what disorders would benefit from an enterostomy tube?
very uncommon- can be used in animals with SEVERE gastric stasis
When considering Purina vivonex as a liquid food for a patient, what should I be aware of?
it is not balanced for dogs/cats (made for people)
and doesn’t have taurine which if used long term in cats may be problematic
What is a balanced liquid food on the market?
Royal Canin Critical Care liquid diets
What are important factors of foods used for critical illness?
palatable, caloric dense
high fat, high protein and low carb
royal canin recovery, Hills a/d, Purina CN
In what conditions are critical illness foods NOT a good idea?
pancreatitis
GI disease and motility disorders
kidney failure
hepatic encephalopathy
