GI Drugs Flashcards
Apomorphine MOA
Emetic
Dopaminergic receptor agonist (D2) in the CRTZ
Dogs only
Cats do not have D2 receptors in their CRTZ
Maropitant MOA
Cerenia
Anti-Emetic
Blocks Substance P from binding to Neurokinin -1 (NK1) receptors in the CRTZ
(NK1 receptors antagonist)
Also acts on NK1 in the GI
Can cause pain during injection
Ondansetron MOA
Zofran
Anti-Emetic
5HT3 receptor antagonist
Inhibits serotonin induced stimulation of vagal afferent activity
Omeprazole MOA
Gastric Acid Reduction
Proton pump inhibitor
(Proton pumps dumps H+ into lumen of stomach)
Famotidine MOA
Gastric Acid Reduction
H2 Receptor antagonist (histamine)
Mirtazapine MOA
AKA carpromorelin (Ghrelin agonist)
Appetite Stimulant/(Anti-emetic)
Anti-anxiety/antidepressant in humans
5-HT3 antagonist (serotinergic antagonist)
Adverse effect in cats: Serotonin syndrome: vocalizing, hyperactivity, agitation, tachycardia
Ghrelin MOA
Appetite Stimulant
The hunger hormone
Synthetic version: carpromorelin
Gabapentin MOA (GI)
Appetite Stimulant
May cause stimulation through reducing stress and anxiety
Metoclopramide MOA
GI Motility
Dopamine antagonist
Incr tone/amp of GI contractions
Relax pyloric sphincter
Incr duodenal/jejunal peristalsis (NO COLONIC EFFECT)
Decr time to empty stomach/GI transit time
Decr gastroesophageal reflux
Cisapride MOA
GI motility
5HT4 (serotonin) agonist
Stim smooth mm of colon
Prednisolone MOA
GI Inflammation
Tx of IBD
Pred most effective for clinical response
Budesonide MOA
GI Inflammation
Treatment of IBD
Similar to pred but GI specific, less off target effects
First pass hepatic metabolism
Cobalamin (Vit B12) MOA
GI supplement
Clinical Importance of the CRTZ input on emesis
Chemoreceptor Trigger Zone
Acting agents: drugs, toxins, pH, metabolites
Clinical Importance of the cerebral cortex input on emesis
Acting agents: scary movies, gross visuals, smells, thoughts
Clinical importance of the vestibular nuclei input on emesis
Acting agents:
Motion sickness, vestibular disease, inner ear infections
Clinical importance of the GI tract input on emesis
Acting agents: inflammation, irritation, stimulation, constipation
Tx recommendation for a nauseous patient
Cerenia and ondansetron together are a powerful pair
Ondansetron might be better for drug induced nausea but more side effects
Common GI side effects of opioid use in humans, cats, and dogs
Decreases activity of the myenteric plexus
= Constipation
Incr nausea, decr gut motility, decr. secretions, decr peristalsis
What is the most appropriate drug fort the treatment of feline constipation?
Cisapride
How is cobalamin absorbed and what are can cause some problems of malabsorption?
In the stomach, cobalamin attaches to R protein which transports it to the small intestine. Cobal binds to intrinsic factor (produced in the pancreas) in the proximal SI then is absorbed in the DISTAL GI > vasculature
Malabsorption: if pancreas does not produce IF or if the distal SI does not absorb
What do parietal cells do in the stomach?
Add acid to stomach
What is the best acid reducer in dogs as per the article?
Omeprazole
Can you give cyproheptadine and mirtazapine at the same time?
Nope
