Miscellaneous Drugs

Question 1

Exocrine pancreatic insufficiency

Answer 1

-failure of exocrine pancreas to produce Lipase amylase and Tripsin for digestion of normal diet
-common in dogs

Question 2

Pancrelipase (Pank-Aid)

Answer 2

-suppliment of exocrine pancreas enzymes (lipase,amylase, proteases)
-mix with food 20mins before feeding, and enzymes begin breaking down food
-can also try ways to increase gastric pH to get enzymes to work better
-wipe nose after eating

Question 3

Treatment of constipation

Answer 3

1. Lubricants
   -mineral oil (cattle, horses)
   -mineral oil + white petroleum (cats for hairballs)
2. Stimulant laxatives
3. Hyperosmotic laxatives
4. Bulk laxatives

Question 4

Stimulant laxatives

Answer 4

-irritate mucosa or intrinsic nerves causing motility
-may also inhibit Na/K ATPase, leading to electrolyte and excess fluid loss?

Question 5

Hyperosmotic laxatives

Answer 5

Draw fluid into GI lumen to stimulate motility

-Sodium phosphate enemas
>not in cats because they absorb phosphate=toxic

-Lactulose
>disaccharide- broken down by microbes in hind gut, drawing in water

-Polyethylene glycol (PEG) powder (ClearLax)
>1/4 tsp mixed in food for cats

Question 6

Bulk laxatives

Answer 6

-non absorbed cellulose material will increase the bulk of fecal material
>Metamucil, prunes, pumpkin

Question 7

Stool softeners

Answer 7

-increase water accumulation in feces
-not beneficial for companion animals

Question 8

Probiotics for diarrhea/constipation

Answer 8

-bacteria or yeast added to food with purpose of regulating intestinal flora

Question 9

Motility disorder drugs

Answer 9

1. Metoclopramide
2. Cisapride

Others: Erythromycin, azithromycin, Cimentidine, ranitidine, Lidocaine

Question 10

Metoclopramide

Answer 10

-inhibits dopamine receptors and serotonin (5HT3) receptors = anti emetic effects

-stimulates serotonin (5HT4) receptors= prokinetic effect

Motility effects: Upper GI
-increase gastric and upper duodenal emptying
-increase gastroesophageal sphincter tone

Question 11

Metaclopramide

Answer 11

-acts on stomach
-could use for megaesophagus and post-op GDV surgery
-limited evidence

Question 12

When not to use Metoclopramine?

Answer 12

-GI obstruction

-neurologic/involuntary muscle movement

-increase prolactin secretion

Question 13

Cisapride

Answer 13

-no approved vet or human formulation; now compounded

-5-HT4 agonist leading to increased Ach
-5-HT3 antagonist but not good for anti-emetic
-more effective prokinetic than Metoclopramide

Question 14

Cisapride uses

Answer 14

Cats:
-increased smooth muscle motility
-megacolon

Dogs:
-increased smooth muscle motility in GI tract
-increases gastroesophageal sphincter tone
-used for delayed emptying and small bowel motility disorders; not for megaesophagus in dogs

Horses:
-ileus after abdominal surgery
-increased motility

Question 15

Cisapride pharmacokinetics

Answer 15

-30-60% in small animals
-longer T1/2 in dogs and cats than in horses and ruminants (2hrs)

-side effects in humans, lead to removal from market

Question 16

Increased motility as a side effect

Answer 16

1. Erythromycin, Azithromycin
   -activate motilin receptors in stomach and proximal small intestines
   -distal GI effects in cattle and horses; little effect in small animals
2. Lidocaine
   -used in horses to reduce post-op ileus but expensive
   -causes excitatory effects on smooth muscle of contractions