Week 4 -GI therapeutics 1 Flashcards
What are the main targets for emetics/ anti-emetics in dogs?
Dopamine receptors
What is the main target for emetics/ anti-emetics in cats?
Sympathomimetic (alpha 2)
What is metaclopraminde?
dopamine (D2) antagonist - supresses CRTZ
and upper GI pro-kinetic stimulant – increases ACh release in
upper GI tract - NB – exclude GI obstruction before use
What is maropitant?
NK1
receptor antagonist – 24 hour action
What is ondansetron?
anti-serotonergic (5-HT). Expensive, used for
patients unable to tolerate, or not controlled by,
metoclopramide or maropitant
When are emetics used?
Emetics are used to induce vomiting following poisoning
* they are only useful if instigated within 2-3 hours of ingestion
* do not induce vomiting if the poison is corrosive, severe CNS, depression, or bad gag reflex
What are apomorphine and ropinrole used for?
- Dopamine agonists
- stimulate the CRTZ centre in dogs
What is xylazine used for?
alpha 2- adrenergic agonist
* stimulates the emetic centre in cats
Why is acid blockade an important part?
- heals oesophageal and gastric ulceration
- treatment of gastritis
What are the two main targets for acid drug therapy?
- Histamine receptors
- H+/ K+- ATPase proton pumps
What is the main function of acid protectants?
- Create a physical barrier
- Acid neutralisation
- Prostaglandin E and its production
What is the function of omeprazole?
- Proton pump inhibitor
- supresses stomach acid secretion
What is the function of antacids?
- not easy to administer
- frequent administration
- not palatable
e.g aluminium hydroxide, magnesium hydroxide…
What is misoprostal
mucousal protectant
- synthetic Prostaglandin E1 analogue
- useful for ulcers caused by NSAIDS
- caution can also cause abortion
What are pro-kinetics used for?
- increase motility
- management of ileus and +/- constipation
What is the function of anti-diarrhoeals?
- decreased motility
- management of diarrhoea
What is the function of metoclopramide?
- increased ACh release in the upper GI tract
- useful for preventing gastro-oesophageal reflux and promoting gastric emptying
What is the function of lidocaine?
infusion in horses improves intraoperative gastric motility
What is the function of laxatives?
- promote elimination or increase fluid content of stools
What is the function of bulk-forming laxatives?
- Mostly plant fibres
- hydrophillic and not digested
- bulk stimulates peristalsis
What is the function of lubricants?
coat the stool with a water-immiscible film, preventing water loss and ease stool passage
What is the function of lactulose?
fermented in the large intestine to acetate and
lactate with consequent osmotic laxative effect. Adjust based
on individual response
How to anti-diarrhoeals act?
by reducing peristalsis to enhance water
reabsorption, demulcent activity or water adsorption
What is the function of loperamide?
opioid agonists – antisecretary, decrease propulsive intestinal contractions and
increase segmentation, increase tone of GI sphincters
What is the function of hyoscine?
antimuscarinic – antispasmodic for equine colic
* Other anti-diarrhoeals (e.g. metronidazole) treat cause
What is the function of kaolin-pectin formulations?
demulcent and adsorbent
