antiemetics by dr. pavulraj.s angels presentation
TRANSCRIPT
![Page 1: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/1.jpg)
Dr. Pavulraj.S
M.V.Sc., (Veterinary Pathologist)
Research fellow
National Research Centre of Equines, India
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 2: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/2.jpg)
DEFINITION
Antiemetics control vomiting by either a
central action or a local protectant effect.
Centrally acting antiemetics may either
block dopaminergic receptor in the CTZ or
depress the emetic centre in the medulla.
Locally acting antiemetics protects the GI
epithelium from further irritation.
Antiemetic therapy should only be
considered as symptomatic therapy
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 3: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/3.jpg)
Clinical applications
Antiemetics are indicated to:
● Control vomiting, when profuse and protracted vomiting may lead to fluid, electrolyte or acid–base disturbances or is causing distress to the patient
● Prevent vomiting predicted to occur with use of emetic drugs, e.g. cisplatin, amphotericin.
Use of antiemetics is not necessary if vomiting is intermittent, the patient is not distressed.
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 4: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/4.jpg)
CLASSES OF ANTIEMETICS
1. Phenothiazines
Clinical applications
Phenothiazines are broad-spectrum antiemetics that have efficacy against vomiting initiated by central and peripheral stimuli.
Mechanism of action
Phenothiazines antagonize α1- and α2-adrenergic receptors, D2-dopaminergic receptors, H1- and H2-histaminergic receptors and muscarinic cholinergic receptors (weakly).
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 5: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/5.jpg)
Dosage DOGS AND CATS
Prochlorperazine
• 0.1–0.5 mg/kg IV, IM, SC q.6-8 h
• 0.5–1.0 mg/kg PO q.8-12 h
NB: Intramuscular injection may be painful
Chlorpromazine
• 0.1–0.5 mg/kg IM, SC q.8 h
Promethazine
Large animals – 1.5-2mg/kg IM
Dog - 1.5-2mg/kg, IM, IV, oral
Triflupromazine
Dog – 2-4mg/kg IM, 1-2mg/kg IV
Cat 2.2-4.4mg/kg IM
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 6: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/6.jpg)
Preparations
Prochlorperazine Emidoxyn - 5mg tablet
Stemetil -5mg tablet
-12.5mg/ml injection
Chlorpromazine Megatil – 25mg tablet
-25mg/ml injection
Chlorpromazine -10mg tablet
Promethazine Avomine -25mg tablet
Phenergan -10mg tablet
-5mg/ml syrup
-25mg/ml injection
Triflupromazine Neocalm – 5mg tablet
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 7: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/7.jpg)
Adverse effects
● Phenothiazines may cause hypotension, arteriolar
vasodilation.
● Sedation, rigidity, tremors, weakness and
restlessness may occur at high dose.
Prochlorperazine may lower the seizure
threshold.
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 8: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/8.jpg)
Known drug interactions
● Phenothiazines should not be given within 1
month of worming with an organophosphate
agent as the effect of either drug may be
potentiated.
● Other CNS-active drugs such as barbiturates,
narcotics and anesthetic agents may cause
additive CNS depression.
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 9: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/9.jpg)
2. Antimuscarinic
i. Metoclopramide Clinical applications Metoclopramide is indicated for control of vomiting
associated with:
● Various emesis-inducing disorders involving
stimulation of the CTZ
depressed gastrointestinal motility
● Cancer chemotherapy
● Gastroesophageal reflux
● Decreased gastric emptying associated with:
– inflammatory gastrointestinal disorders
– gastric ulcers
– gastric neoplasia
– autonomic neuropathy (diabetes mellitus)
– postoperative gastric dilation and volvulus
surgery/intervention
– abnormal gastric motility.
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 10: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/10.jpg)
Mechanism of action
Centrally, metoclopramide antagonizes D2-
dopaminergic receptors and 5-HT3
serotonergic receptors and peripherally
cholinergic effect.
The antiemetic properties of
metoclopramide related to 5-HT3receptor
antagonism
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 11: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/11.jpg)
Dosage
DOGS AND CATS
• 0.2–0.5 mg/kg PO q.6–8 h
0.01- 0.2mg/kg SC,IM,IV
Preparations Emenil – 10mg tablet
- 5mg/ml injection
Perinorm – 10mg tablet
- 5mg/ml injection
Reglan – 10mg tablet
- 5mg/ml injection
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 12: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/12.jpg)
Adverse effects
Side effects more often in cats than in dogs.
Metoclopramide should not be used when
gastrointestinal hemorrhage, obstruction or
perforation is suspected.
Contraindicated in patients with seizure
Use with caution renal insufficiency because it
reduces renal blood flow
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 13: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/13.jpg)
Known drug interactions
● Excellent synergy with metoclopramide and
phenothiazines
● Anticholinergic drugs (e.g. atropine) affects metoclopramide on gastrointestinal tract motility.
● The gastrointestinal stimulatory effects of metoclopramide may affect absorption of many drugs.
● Metoclopramide may enhance the absorption of cimetidine, aspirin, tetracyclines, diazepam.
● Metoclopramide antagonizes the antiprolactinemic effects of cabergoline.
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 14: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/14.jpg)
ii. Domperidone
Clinical applications
Domperidone is a dopamine antagonist at D2-
receptors which has similar actions to
metoclopramide.
Mechanism of action
Domperidone is a dopamine antagonist in
the CTZ and GI tract. It also is an α2- and
β2-adrenergic antagonist in the stomach.
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 15: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/15.jpg)
Dosage
DOGS AND CATS
• 5-10 mg per animal q.8 h
Preparations
Domel-MT - 10mg tablet
Domstal – 10mg tablet
-1mg/ml susp
Tridom - 5mg tablet
-1mg/ml susp
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 16: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/16.jpg)
Adverse effects
It may cause gastroparesis.
The drug is teratogenic at high doses in mice, rats and rabbits.
Domperidone may increase prolactin levels resulting in galactorrhea or gynecomastia.
There may be an impact on fertility
Known drug interactions
Domperidone should not be used with dopaminergic
drugs such as dopamine or dobutamine.
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 17: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/17.jpg)
3. 5-HT3 antagonists
Ondansetron
Clinical applications
Extremely potent antiemetics
Clinical efficacy is better than metoclopramide
Used in cases when ‘first-line’ antiemetics (e.g.metoclopramide or chlorpromazine) are ineffective.
Control vomiting in puppies with parvoviral gastroenteritis.
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 18: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/18.jpg)
Mechanism of action
5-HT3 receptors are located in the CTZ and,
peripherally, on vagal nerve terminals and
on enteric neurones in the gastrointestinal
tract.
5-HT3 antagonists have a central action on
the CTZ and peripheral 5-HT3 receptors in
the gut.
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 19: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/19.jpg)
Dosage
DOGS
• 0.5 mg/kg IV as a loading dose and then 0.5
mg/kg/h as an infusion for 6 h
0.5-1 mg/kg oral
Contraindicated in cats
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 20: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/20.jpg)
Preparations
Emeset - 4mg tablet
-2m/5 ml syrup
-2mg/ml injection
Vomiz- 4mg tablet
-2mg/ml syrup
Zondan – 4mg tablet
-2mg/ml syrup
Vomidon - 2mg/ml injection
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 21: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/21.jpg)
Adverse effects
Showing minimal toxicity at doses up to 30 times greater.
Should be used with caution in cases where gastrointestinal obstruction cannot be excluded.
Some time produce constipation, headaches, alterations in liver enzymes and rarely hypersensitivity reactions .
Should be used with caution in pregnant animals.
Ondansetron is a potential substrate of P-glycoprotein. Some rough collies have a mutation causing a nonfunctional protein, these dogs and associated breeds may be more sensitive to the effects of 5-HT3 antagonists.
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 22: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/22.jpg)
Inappropriate use of
antiemetics
Use of antiemetics in the following situations is
inappropriate:
● Gastrointestinal obstruction – antiemetics may delay
diagnosis
● Gastrointestinal toxicity – antiemetics may prevent
the patient from eliminating the toxin
● Systemic hypotension – the phenothiazines and
α2-adrenergic antagonists, when used in high doses, can intensify hypotension.
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India
![Page 23: Antiemetics by dr. pavulraj.s angels presentation](https://reader034.vdocuments.site/reader034/viewer/2022042512/55a721021a28ab3b0a8b458f/html5/thumbnails/23.jpg)
2/15/2015
Dr. Pavulraj.S., M.V.Sc., Veterinary Pathologist,
Research Fellow, NRCE, India