What are the common prescription medications and treatment approaches for managing vomiting in India?

Common Prescription Medications for Vomiting in India

Ondansetron is the first-line antiemetic medication for vomiting in India due to its superior efficacy and safety profile compared to other antiemetics. 1

Classification of Antiemetic Medications Available in India

5-HT3 Receptor Antagonists (First-line options)

• Ondansetron: 8 mg PO/IV every 6 hours or 16-24 mg PO daily 1, 2

  • Most widely used and effective antiemetic
  • Available as tablets, oral disintegrating tablets, oral solution, and injection
  • Preferred for both adults and children

• Granisetron: 1-2 mg PO daily or 1 mg PO twice daily or 0.01 mg/kg IV (maximum 1 mg) 1

  • Available as tablets and injection
  • Also available as transdermal patch (3.1 mg/24 h patch containing 34.3 mg granisetron)

• Palonosetron: 0.25 mg IV (preferred for chemotherapy-induced vomiting) 1, 3

  • Longer half-life than other 5-HT3 antagonists
  • Usually administered as single dose

• Ramosetron: Highly effective with RR 0.44 compared to placebo 4

  • Newer 5-HT3 antagonist gaining popularity in India

Dopamine Receptor Antagonists

• Metoclopramide: 10-20 mg PO/IV every 4-6 hours 1

  • Also improves gastric emptying
  • Risk of extrapyramidal symptoms, especially at higher doses

• Domperidone: 0.5 mg/kg in children; 10 mg PO three times daily for adults 5

  • Less central nervous system effects than metoclopramide
  • Commonly used in India for gastritis-related vomiting

• Prochlorperazine: 10 mg PO/IV every 6 hours or 25 mg suppository every 12 hours 1

  • Effective but has risk of sedation and extrapyramidal symptoms

Corticosteroids

• Dexamethasone: 8-12 mg PO/IV daily 1
  • Often combined with 5-HT3 antagonists for enhanced effect
  • Particularly effective for chemotherapy-induced and postoperative vomiting

NK1 Receptor Antagonists (For specialized use)

• Aprepitant: 125 mg PO day 1, then 80 mg PO daily days 2-3 1
  • Used primarily for chemotherapy-induced vomiting
  • Often part of combination therapy for highly emetogenic chemotherapy

Antihistamines and Anticholinergics

• Promethazine: 12.5-25 mg PO/IV every 4-6 hours 1

  • Causes significant sedation
  • Used when sedative effect is desirable

• Dimenhydrinate: For motion sickness and postoperative vomiting 6

  • Available as tablets and injection

Treatment Approach Based on Cause of Vomiting

Acute Gastroenteritis

1. First-line: Ondansetron 8 mg PO/IV every 6 hours (adults) or 0.15 mg/kg (children) 5

   • Facilitates oral rehydration therapy
   • Reduces need for IV fluids and hospitalization

2. Alternative: Domperidone 10 mg PO three times daily (adults) or 0.5 mg/kg (children) 5

   • Less effective than ondansetron (85% vs 95% cessation of vomiting at 24 hours)
   • Better tolerated in some patients

Chemotherapy-Induced Vomiting

For highly emetogenic chemotherapy:

1. Combination therapy (preferred): 1

   • 5-HT3 antagonist (ondansetron 16-24 mg PO or 8-24 mg IV day 1)
   • PLUS dexamethasone 12 mg PO/IV day 1, then 8 mg daily days 2-4
   • PLUS NK1 antagonist (aprepitant 125 mg PO day 1, then 80 mg daily days 2-3)

2. Alternative: Palonosetron 0.25 mg IV (preferred 5-HT3 antagonist for chemotherapy) plus dexamethasone 1

Postoperative Nausea and Vomiting

1. Prophylaxis: 3, 2, 4

   • Ondansetron 4-8 mg IV before end of surgery
   • OR granisetron 1 mg IV
   • Consider adding dexamethasone 4-8 mg IV for high-risk patients

2. Treatment of established PONV: 1

   • Ondansetron 4 mg IV if not used for prophylaxis
   • OR promethazine 12.5-25 mg IV
   • OR metoclopramide 10 mg IV

Pregnancy-Related Vomiting

1. First-line: Non-pharmacological approaches (small frequent meals, ginger)
2. Second-line: Antihistamines (promethazine)
3. Severe cases: Ondansetron (benefit outweighs theoretical risk)

Breakthrough Vomiting Management

For persistent vomiting despite initial therapy: 1

1. Add one agent from a different drug class to the current regimen:

   • If using 5-HT3 antagonist, add dexamethasone 12 mg PO/IV
   • If using dopamine antagonist, add ondansetron 8 mg PO/IV
   • Consider olanzapine 5-10 mg PO daily for refractory cases (category 1 evidence)

2. For continued vomiting:

   • Re-evaluate cause
   • Consider dose adjustments
   • Switch to combination therapy with multiple antiemetic classes

Common Pitfalls and Caveats

1. QT prolongation risk: Monitor ECG when using ondansetron in patients with cardiac disease or electrolyte abnormalities 1, 7

2. Extrapyramidal symptoms: Monitor for acute dystonic reactions with metoclopramide and prochlorperazine; treat with diphenhydramine 25-50 mg PO/IV 1

3. Sedation: Promethazine and other antihistamines cause significant sedation; avoid in outpatients who need to remain alert 1

4. Olanzapine caution: Use at low doses (2.5 mg) in elderly patients due to black box warning regarding increased mortality in elderly patients with dementia 1, 7

5. Combination therapy: More effective than monotherapy for severe vomiting but increases risk of adverse effects 1

6. Non-pharmacological approaches: Always consider dietary modifications (small frequent meals, room temperature food) alongside medications 1

By following these evidence-based approaches to antiemetic therapy, clinicians in India can effectively manage vomiting across various clinical scenarios while minimizing adverse effects.