Emetics and Anti-emetics (Pharmacology III)

Emetics and antiemetics, emesis, classification, mechanism, contraindication, drugs for emetics and antiemetics, Neuroleptics, pro kinetic drugs

1. EMETICS AND ANTIEMETIC'S
Submitted By:
Muhammad Mehedi Hasan

K.M.Naimul Islam
Ahasan Habib Opu
Syeda Mahjabin Alam
Samieatul Bashar
Submitted to:
A.F. M. Towheedur Rahman
Senior Lecturer
Department of Pharmaceutical
sciences
North South University

2. EMESIS
A protective reflex
that serves to rid the
stomach and intestine
of toxic substances
and prevent their
further ingestion.

3. CLASSIFICATION OF EMETICS
1. Stimulants of CTZ
 Apomorphine
 Morphine
2. Irritants of gastric mucosa
 Mustard
Sodium chloride
3. Both CTZ stimulant and irritant effect
• Pecacuanha
•Digitalis

4. EMETICS
Apomorphine
 Morphine derivative – semi-synthetic
 6 mg IM/SC – acts within 5 minutes
Respiratory depression
 Parkinsonism
Ipecacuanha
•Dried root of Cephaelais ipecacuanha.
• Syrup ipecac – 15 to 30 ml (10 to 15 in child)
• Action takes 15 minutes

5. MUSTARD
•Volatile oil
•It is a household remedy to induce vomiting
•It is safe and easily available
•Dose -1 tp in water

6. MECHANISM OF ACTION

7. CONTRAINDICATION
 Hernias
 Severe heart diseases
 Peptic ulcer
 Pulmonary TB
 CNS stimulant drug poisoning
 Kerosine (petroleum) poisoning
 Unconscious patient

8. LIST OF DRUGS INDUCE VOMITING
 Anticancer drugs
Apomorphine
Chloroquine, quinine
Diltiazem
Emetine
Ergot derivatives
Erythromycin, tetracycline
Fluoroquinolones
Metronidazole

9. ANTIEMETICS
Antiemetic drug or Anti
vomiting drug are those
drugs which is responsible
for the prevention of the
vomiting.

10. MECHANISM OF ACTION

11. CLASSIFICATION
1. Anticholinergic Drug
 Hyoscine, Dicyclomine
2. H1 Antihistaminic
 Promethazine, Diphenhydramine, Cinnarizine, Cyclizine, Doxylamine
3. Neuroleptics
 Haloperidol, Prochlorperidol, Prochlorperazine
4. Prokinetic Drug
 Domperidone, Cisapride, Mosapride, Metochlopramide
5. 5-HT3 Antagonist
 Granisteron, Ondansteron
6. Adjuvant Antiemetics
 Dexamethasone, Benzodiazepine, Cannabinoids

12. ANTICHOLINERGIC DRUGS
 Hyoscine
 Most effective drug for motion sickness.
Action:
Probably by blocking conduction of nerve impulses across a cholinergic link in the pathway
leading from vestibular apparatus to vomiting center & is not effective in vomiting of other
etiologies.
Dose:
Hyoscine is used 0.2-0.4mg as oral or intramuscular.
Use:
Hyoscine is mostly used in motion sickness. But it also produces sedation and anticholinergic
side effect.

13. CONTINUE….
SIDE EFFECTS:
Sedation
CNS excitation,
Dry mouth
Urinary retention
Blurred vision
Confusion
Disorientation
Hallucination

14. H1- ANTIHISTAMINIC DRUGS
 These agents most likely act by inhibiting cholinergic pathways of the vestibular
apparatus by receptor “crossover.”
 H1-receptor antagonists are used to treat motion sickness and vertigo.
 These agents produce sedation and dry mouth.

Promethazine
 Promethazine is the first generation of H1 receptor
antagonist used as antihistamine antiemetic.
Drugs:
phenargan, Promethagan

15. CONTINUE….
Indications:
Sedative
 Anti allergic
Adjunct in Motion sickness
Morning sickness.
Side effects:
Respiratory depression
Seizures

16. NEUROLEPTICS
¥ Potent antiemetics
¥ Act by blocking D2 receptors in the CTZ
¥ Antagonize Apo morphine induced vomiting
¥ Antiemetic dose is much lower than antipsychotic doses
¥ These agents should not be administered until the cause of vomiting
has been diagnosed.

17. CONTINUE….
Prochlorperazine:
 It is a dopamine receptor antagonist used for
treatment of nausea & vertigo.
 It is also a highly potent typical antipsychotic &
more potent than chlorpromazine.
Uses:
 Treat Migraine headaches
 An Anti-psychotic
 Alleviates labrynthitis.
Side Effect:
Drowsiness, Difficulty falling, Dizziness, Increased appetite, weight gain, Dry
mouth, Blurred vision

18. PROKINETIC DRUG
 These drugs which promote gastrointestinal motility and quicken gastric emptying .
 Prokinetic drug are block Dopamine D2 receptor, it produces antiemetic action due
to blockage of D2 receptor in CTZ.
 It also acts by enhancing Acetylcholine(Ach) from cholinergic neuron in the gut.

Metoclopramide
 It is a prokinetic drug that promotes
g.i. transit & gastric emptying.
Action:
In the GIT & CNS through D2 & 5-HT antagonism
& 5-HT4 antagonism.

19. CONTINUE….
Uses:
oAntiemetic,
o Gastro kinetic
oDyspepsia
oGastroesophageal reflux disease.
Adverse Effects:
 Sedation
Dizziness
Loose stool
Muscle dystonia
 Galactorrhoea

20. ONDANSETRON
It is a prototype developed to control cancer chemotherapy or
radiotherapy induced vomiting.
Action:
Reduces the activity of vagus nerve which deactivates the vomiting center &
also blocks the action of 5-HT3.
Uses:
 Prevents Chemotherapy
 Post operative nausea
 Vomiting
5-HT3 ANTAGONIST

21. CONTINUE….
Side Effects:
 Constipation
Dizziness
Headache
Clinical Use:
CIV
Parkinson’s disease
Alcoholism

22. ADJUVANT ANTIEMETICS
Benzodiazepine (nabilone)
Action based on sedative property.
 Weak antiemetics
 Use as an adjuvant to other antiemetic.
Use:
1.Panic disorder
2. Seizures
3. Alcohol withdrawal
Adverse effects
•Cognitive effects
• Paradoxical effects
• Reinforcement disorders