GI Pharmocology Flashcards
Neurotransmitter : Dopamine
What is the receptor?
Receptor : D2 Dopaminergic
Neurotransmitter :
5-Hydroxytryptamine
What is the receptor?
Receptor : 5-HT3 — Serotonergic
Neurotransmitter : Acetylcholine
What is the receptor?
Receptor : M1-Cholinergic
Neurotransmitter : Histamine
What is the receptor?
Receptor : H1/H2 — Histaminergic
Neurotransmitter : Norepinephrine
What is the receptor?
Receptor : A2 — Adrenergic
Neurotransmitter : Leu-enkephalin
What is the receptor?
Receptor : ENK - Enkephalinergic
Neurotransmitter : Substance P
What is the receptor?
Receptor : NK-1
Cat receptors for emesis
5-HT3 (serotonergic)
A2 (adrenergic)
Dog receptors for emesis
H2 (histaminergic)
D2 (dopaminergic)
What is used to induce emesis in cats?
Dexmedetomidine/Xylazine (alpha2 agonist)
Emetogenic in cats
What is used to induce emesis in dogs.
Apomorphine (D2 dopaminergic agonist)
Emetogenic in dogs
Phenothiazines
Blocks what receptors?
Side effects?
Blocks dopamine receptors in the CRTZ
Blocks dopamine receptors in the vomiting center
Hypotension ; due to alpha blockade
May cause sedation
Metoclopramide
Drug class?
What receptors?
MOA?
Side effects?
Dopamine antagonist (pro kinetic)
Blocks dopamine (D2) receptors in CRTZ
Stimulate stomach & duodenal motility via increased smooth muscles sensitivity to acetylcholine
Extra-pyramidal signs (motor restlessness/hyperactivity) —> crosses BBB; cisapride does not
*Not as effective in cats
Ondansetron
Drug class?
What receptors?
(5-HT3) Serotonin antagonist
5-HT3 receptors are found in the CRTZ, vagal afferents and gut enteric neurons
Maropitant
What receptors?
Broad Spectrum?
Peak plasma conc. @__ hrs SQ?
How is it cleared?
MOA?
Selective (NK-1) neurokinin receptor antagonist
Central and peripheral activity
0.75 hours
Hepatic clearance
NK-1 receptors are densely distributed within emetic center (also CRTZ) maropitant acts to directly inhibit vomiting by blocking Substance P binding at the NK-1 receptors in the CNS
