22 – GI Miscellaneous Flashcards
Exocrine pancreatic insufficiency
- Failure of exocrine pancreas to produce Lipase Amylase and Tripsin for DIGESTION of normal diet
- Mainly in dogs
What can be used to treat exocrine pancreatic insufficiency?
- *Pancrelipase (Pank-Aid)
- (Octreotide (Sandostatin))
- (Fuzapladib (Panoquell-CA1))
Pancrelipase (Pank-Aid) (‘ground pancreas’)
- Supplement of exocrine pancreas enzymes (lipases, amylase and proteases)
- Mix it with the food, let it sit so it can start to ‘digest’ the food before feeding it to the dog
- increased gastric pH may increase the amount of active enzyme reaching duodenum
- should wipe mouth after eating as it will ‘break down’ the nose structure
What might be used to treat constipation?
- Lubricants
- (stimulant laxatives)
- Hyperosmotic laxatives
- Bulk laxatives
- Stool softeners
Lubricants to treat constipation
- Mineral oil: cattle, horses
- Mineral oil + white petroleum: cats=hairball remedy
- *if get into lungs=bad pneumonia that will kill them!
o NEEDS to go into the stomach
Stimulant laxatives
- Irritate the mucosa or intrinsic nerves (ENS) causing motility
Hyperosmotic laxatives
- Draw fluid into GI lumen to stimulate motility
What are some examples of hyperosmotic laxatives?
- *Polyethylene glycol (PEG) powder
o ¼ tsp: Mix in food for cats - Sodium phosphate enemas: do NOT use in cats
o Can cause hyperphosphatemia (absorb P=toxic) - Lactulose
o Non-digestible sugar
Bulk laxatives
- Non-absorbed cellulose material with INCREASE the bulk of fecal material
o Hydrophilic colloids: Metamucil (Drink right away, otherwise it will turn into gel)
o Fiber: prunes, pumpkin
Stool softeners (not really used)
- Increase water accumulation in feces
- Docusates
o (Dioctyl sodium sulfosuccinate)
o (Dioctyl calcium sulfosuccinate)
Probiotics for diarrhea/constipation (theory)
- Bacteria or yeast added to food with purpose of relating intestinal flora
- Mechanism of action: unknown
- No reports of adverse effects
o Downsides might be lack of efficacy and expense
Trying to fix motility drugs
- Really DOESN’T work
Motility-modifying drugs
- Metoclopramide: upper GI
- Cisapride: lower and upper GI
*used as a prokinetic
Motility-modifying drugs that have prokinetic effect as a side effect
- Erythromycin, azithromycin
- Cimetidine, ranitidine
- Lidocaine
Metoclopramide (injectable solution)
- Inhibits dopamine receptors
- Inhibits serotonin receptors (5HT3)
- *stimulates serotonin receptor (5HT4)
o Accounts for prokinetic effect - *UPPER GI (stomach)
Metoclopramide in upper GI
- Prokinetic effect: increase gastric and upper duodenal emptying
- Increase gastroesophageal sphincter tone
Metoclopramide adverse effects
- Make sure there is NO GI obstruction
- Watch for extrapyramidal effects
- Can increase prolactin secretion
Metoclopramide in horses
- AVOID
Cisapride
- No approved vet or human formulation
o Formerly Prepulsid (human tablets)
o Now compounded products only
What is Cisapride mechanism of action
- 5-HT4 agonist
- 5-HT3 antagonist
- Likely more effective prokinetic
Cisapride vet uses in cats
- Increase smooth muscle motility
o Used for MEGACOLON
Cisapride vet uses in dogs
- Increase smooth muscle motility throughout GIT
o Increase gastroesophageal sphincter one
o Delayed emptying, small bowel motility disorders
o Not effective for megaesophagus in dogs (little smooth muscle present)
Cisapride vet uses in horses
- Treatment of ileus after abdominal surgery (IV use)
o Co-ordinated motility in ileum/cecum/colon
PK of Cisapride
- 30-60% oral bioavailability
- Longer half life in dogs and cats than horses and ruminants
Adverse effects of Cisapride
- Cardiac arrythmias and drug interactions
- Not reported in dogs and cats: but can happen
Erythromycin, Azithromycin
- Though to activate motilin receptors in stomach and SI
- LITTLE effect
- Not available
- Can cause vomiting and irritation?
Lidocaine
- Horses to reduce post-op ileus (IV infusion)
o VERY EXPENSIVE - Adverse effects: muscle fasciculations, ataxia, seizure
