The document discusses the pharmacology and classification of anti-emetic drugs used to control nausea and vomiting, detailing both emetics and anti-emetics. It explores their mechanisms, classifications including anti-cholinergics, H-1 antihistaminics, neuroleptics, prokinetic drugs, and 5-HT3 antagonists, along with their applications, dosage, and side effects. Additionally, the document outlines contraindications for emetic use and specific drugs' effectiveness.

1. ANTI – EMETICS
PHARMACOLOGY & CLASSIFICATION
Name – Yogeeta

2. EMESIS
🌷 It is protective mechanism which serves to eliminate harmful substances from the
stomach.
🌷 Occurs due to stimulation of the emetic center situated in the medulla oblongata.
🌷 Multiple pathways can rlicit vomiting.
🌷 CTZ and NTS are the most important relay areas for afferent impulsesarisibg from
GIT, throat and other viscera.
🌷 CTZ also accessible to blood borne drugs, mediators, hormones, toxins, etc.

3. 🤮 EMETICS 🤮
🌼 These are the drugs which are used to evoke vomiting.
1️⃣ Centrally acting – Apomorphine ( directly stimulate the CTZ or VC )
2️⃣ Peripherally acting – mustard , potassium tartrate, and hypertonic NaCl (
concentrated solutions )
3️⃣ Both – Ipecacuanha ( stimulate the VC by irritating gastric & duodenal mucosa
which stimulate afferent fibres of vagus nerve)

4. 👉🏻 Apomorphine 💉
✏️ Semi synthetic derivative of morphine.
✏️ Given IM or SC, acts centrally.
✏️ Dose is 6 mg ( 2-8 mg )
✏️ Induces vomiting in 5-10 minutes.
✏️ Not given if respiration is depressed.
👉🏻 Ipecacuanha 🧂
✏️ Contains two alkaloids – emetine &
cephaeline .
✏️ Used as syrup ipecac.
✏️ Produces effect in 15 minutes.
✏️ Acts by irritating gastric mucosa & through
CTZ centre.
✏️ Dose – 5 ml in infants, 10-15 ml in children,
15-20 in adults.

5. 🌼 CONTRAINDICATIONS 🚫
• 🌸 Corrosive ( acid, alkali ) poisoning.
• 🌸 CNS stimulant drug poisoning.
• 🌸 Kerosine ( petroleum ) poisoning.
• 🌸 Unconscious Patient
• 🌸 Morphine or phenothiazine poisoning.

6. 🤮 INTRODUCTION – ANTI EMETICS
🌿 Two Centres
- Vomiting Centre (VC)
- Chemoreceptor trigger zone (CTZ)
🌿 Both near to the floor of the fourth ventricle, close to the vital centres.
🌿 VC is within the BBB
🌿 CTZ outside in the area postrema & they both are connected together.
🌿 Def. - A group of drugs which are used to control the nausea and vomiting.

8. 🏥 CLASSIFICATION
🌺 Anti-Cholinergics
• Hyoscine
• Dicyclomine
🌺 H-1
Antigistaminics
• Promethazine
• Diphenhydramine
• Doxylamine
• Meclozine
Neuroleptices
(D-2 blockers)
• Chlorpromazine
• Triflupromazine
• Prochlorperazine

9. CONTD…. 💊💉
🌺 Prokinetic Drugs
• Metoclopramide
• Domeperidone
• Cisapride
• Mosapride
• itopride
🌺 5-HT3 antagonists
• Ondansetron
• Granisetron
• Palonosetron
• Ramosetron
🌺 Adjuvant-
antiemetics
• Dexamethasone
• Benzodiazepines
• Dronabinol

10. 1. ANTICHOLINERGICS
👉🏻 HYOSCINE –
• 0.2 – 0.4 mg oral, i.m.
• Most effective for motion sickness
• Brief duration of action – produce sedation, dry mouth and anticholinergic side
effects.
👉🏻 DICYCLOMINE –
• 10-20 mg oral
• Prophylaxis of morning & motion sickness

11. 🍁H-1 ANTIHISTAMINICS🤮
• Some antihistaminics are antiemetic like promethazine, diphenhydramine,
dimenhydinate.
• They protect from motion sickness for 4-6 hours.
• Produce sedation & dryness of mouth so driving should not be proceede after having
these drugs.
• Combination of these with other antiemetics has been used in chemotherapy-
induced nausea and vomiting (CINV)

12. 🍁NEUROLEPTICS🤮
• The older neuroleptics ( phenothiazines, haloperidol) are potent antiemetics and
sedative.
• They act by blocking D2 receptors in the CTZ; antagonize apomorphine induced
vomiting.
👉🏻 Useful in –
- Drug induced vomiting
- Post operative nausea and vomiting
- Radiation sickness vomiting

13. 🍁PROKINETIC DRUGS 💉
• These drugs promote GIT transit and speed gastric emptying by rnhancing
coordinated propulsive motility.
• They acts through both dopaminergic and serotonergic receptors.
• D-2 antagonism
• 5-HT3 agonism
• Sedation, dizziness, loose stools, muscle dystonias are the main side effects.
• Long term use can cause parkinsonism, galactorrhoea and gynaecomastia.

14. 🍁5 – HT3 ANTAGONISTS 💊
• Ondansetron is prototype developed to control cancer chemotherapy induced
vomiting.
• Cytotoxic drugs produces nausea & vomiting by causing cellular damage, which
releases mediators including 5- HT from intestinal mucosa resulting in transmission
of impulses to the NTS and CTZ.
• Oral bioavailability of ondansetron is 60-70 % due to first pass metabolism.
• Elimenated by urine and faeces t1/2 is 3-5 hrs.

15. 🌷THANK-YOU🌷