THE INDIAN PHARMACIST Official Circular Pharmacy Logo THE INDIAN PHARMACISTLearn. Explore. Practise. Excel.
MEDICINE MONOGRAPH CODE: [5.7] ID: TIP-MED-000075

Ondansetron

Active Ingredient / Scientific Identity: Ondansetron • Class: Selective Serotonin 5-HT3 Receptor Antagonist; Central & Peripheral Antiemetic

⚖️ Compare Profile
Generic / Entity NameOndansetron ([5.7])
Verified Indian Brands / RefGeneric Compendial Entry (No Commercial Brand Claimed)
Pharmacological ClassSelective Serotonin 5-HT3 Receptor Antagonist; Central & Peripheral Antiemetic
Available Dosage FormsOral Film-Coated & Mouth-Dissolving (MD / ODT) Tablets: 4 mg, 8 mg; Oral Syrup: 2 mg/5 mL; Parenteral Injectio
Regulatory ClassificationSchedule H Prescription Drug • NLEM 2022 Core Essential Medicine
Key Warning & Review DateIn severe hepatic impairment (Child-Pugh C), clearance drops by >50%; do NOT exceed a total daily dose of 8 mg.
Reviewed: 2026-11-10
Safety Matrix:⚖️ Legal Status: Schedule H Prescription Drug • NLEM 2022 Core Essent✔️ Standard Clinical Dispensing Precautions

1. Clinical & Scientific Overview

Ondansetron (TIP-MED-000075, Reference Code [5.7]) is classified under Gastrointestinal & Hepatobiliary Medicines (Ch 05) as a Selective Serotonin 5-HT3 Receptor Antagonist; Central & Peripheral Antiemetic. Within the Indian regulatory and compendial framework, it is governed under Schedule H Prescription Drug • NLEM 2022 Core Essential Medicine.

Verified Indian Market Examples / Compendial Status:
Representative Indian Market Examples (Edition 2.7 Ch 05 [5.7], p. 63): Emeset (Cipla), Vomikind / Vomikind-MD (Mankind), Ondem / Ondem-MD (Alkem), Zofer (Sun Pharma), Periset (Ipca) — Strengths & Forms: Oral Film-Coated & Mouth-Dissolving (MD / ODT) Tablets: 4 mg, 8 mg; Oral Syrup: 2 mg/5 mL; Parenteral Injection: 2 mg/mL (2 mL = 4 mg, 4 mL = 8 mg)
Representative Indian Market Examples (Edition 2.7 Ch 05 [5.7], p. 63): Emeset (Cipla), Vomikind / Vomikind-MD (Mankind), Ondem / Ondem-MD (Alkem), Zofer (Sun Pharma), Periset (Ipca) — Strengths & Forms: Oral Film-Coated & Mouth-Dissolving (MD / ODT) Tablets: 4 mg, 8 mg; Oral Syrup: 2 mg/5 mL; Parenteral Injection: 2 mg/mL (2 mL = 4 mg, 4 mL = 8 mg)
Dosage Forms & Available Strengths:
Oral Film-Coated & Mouth-Dissolving (MD / ODT) Tablets: 4 mg, 8 mg; Oral Syrup: 2 mg/5 mL; Parenteral Injection: 2 mg/mL (2 mL = 4 mg, 4 mL = 8 mg)
Routes: Oral / Parenteral / Topical as specified by formulation

3. Mechanism of Action & Pharmacodynamics

Selectively antagonizes ligand-gated ionotropic 5-HT3 (serotonin type 3) receptors both peripherally on vagal nerve terminals in the gastrointestinal mucosa (stimulated by serotonin released from enterochromaffin cells) and centrally in the Chemoreceptor Trigger Zone (CTZ / Area Postrema) and Nucleus Tractus Solitarius (NTS). Does not block dopamine D2 or muscarinic receptors (zero extrapyramidal symptoms).

4. Therapeutic Indications & Evidence-Supported Uses

  • Prevention and treatment of Chemotherapy-Induced Nausea and Vomiting (CINV) and Radiotherapy-Induced Nausea and Vomiting (RINV)
  • Prevention and treatment of Post-Operative Nausea and Vomiting (PONV)
  • Acute gastroenteritis-associated vomiting in children and adults

🇮🇳 Jurisdiction & Indication Note: Indications and schedules reflect Indian compendial and regulatory records (CDSCO / Indian Pharmacopoeia & NFI / NLEM 2022). Where international reference labels (US FDA DailyMed / NCBI StatPearls) are cited for pharmacokinetic or mechanistic parameters, international approvals do not automatically imply CDSCO approval in India.

5. Educational Dosage Context, Formulations & Administration

Educational Dosing & Regimen Summary: Adults: 4–8 mg orally or slowly IV q8h as needed. Maximum single IV dose is 16 mg (due to dose-dependent QT prolongation risk).

Administration & Meal Timing: Oral (conventional tablet or orally disintegrating tablet placed on tongue) or Intravenous (over 2–5 minutes or 15-min infusion).

6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment

Absorption & Disposition:
Absorption, distribution, metabolism, and excretion follow class pharmacokinetic profile; verify patient renal/hepatic function.
Metabolism & Biotransformation:
In severe hepatic impairment (Child-Pugh C), clearance drops by >50%; do NOT exceed a total daily dose of 8 mg.
Elimination & Renal Adjustment:
No dose adjustment required in renal impairment.
Hepatic Impairment Considerations:
In severe hepatic impairment (Child-Pugh C), clearance drops by >50%; do NOT exceed a total daily dose of 8 mg.

7. Contraindications, Precautions & High-Risk Warnings

Contraindications & Red-Flag Precautions:
  • Congenital Long QT Syndrome
  • Concomitant Apomorphine (profound hypotension and loss of consciousness)

Key Clinical Precautions: In severe hepatic impairment (Child-Pugh C), clearance drops by >50%; do NOT exceed a total daily dose of 8 mg.

8. Adverse Effects Profile

Common & Mechanism-Related Adverse Effects:
  • Headache (most common, 10%–20%) and constipation (due to slowed colonic transit)
  • Dose-dependent QTc interval prolongation (especially single IV doses >16 mg or with hypokalaemia/hypomagnesaemia)
  • Transient asymptomatic transaminase elevation
Serious / Dose-Limiting Adverse Effects:
  • Monitor for severe hypersensitivity, organ toxicity, or dose-limiting adverse events.

9. Major Drug–Drug, Drug–Food & Drug–Herb Interactions

  • QT-prolonging drugs (Amiodarone, Macrolides, Fluoroquinolones, Haloperidol, Domperidone): additive QTc prolongation and Torsades de Pointes risk
  • Serotonergic drugs (SSRIs, SNRIs, Tramadol, Linezolid): potential additive serotonin syndrome
  • Tramadol: Ondansetron blocks spinal 5-HT3 pathways and may partially attenuate Tramadol analgesia

10. Clinical Monitoring, Patient Counselling & Storage

Clinical & Laboratory Monitoring: Monitor clinical response, baseline renal/hepatic parameters, and relevant serum biomarkers.

Pharmacist Patient Counselling Points:

  • For Orally Disintegrating Tablets (MD), peel back the blister foil with dry hands (do not push tablet through foil) and place on tongue to dissolve.
  • May cause mild headache or constipation; maintain adequate hydration.
  • Ineffective for motion sickness (which requires vestibular H1/M1 blockers like Promethazine or Hyoscine).

Storage, Stability & Dispensing Safeguards: Store below 30°C protected from light.

11. Visual Pharmacology & Mechanism Diagram (svg-v339-01-adme-12-step-journey)

THE 12-STEP ORAL DRUG JOURNEY THROUGH THE HUMAN BODY (LADME) Note: IV bolus enters Step 6 directly (F = 100%); Sublingual & Transdermal routes bypass Step 4–5 Portal First-Pass Metabolism 1. Oral Administration • Tablet / Capsule swallowed • Gastric emptying to duodenum pH 1.5–3.5 (Stomach) 2. Disintegration & Dissolution • Tablet breaks into granules • API dissolves in GI fluid Noyes-Whitney Dissolution Rate 3. GI Epithelial Absorption • Crosses intestinal villi • Passive / Active / P-gp efflux Small Intestine (Large Surface Area) 4. Portal Circulation • Mesenteric veins → Portal vein • Delivers blood to liver sinusoids Pre-systemic Venous Conduit 5. First-Pass Metabolism • Gut & hepatic CYP450 extraction • High: GTN, Propranolol, Morphine Determines Bioavailability (F = f_a × (1-E_H)) 6. Systemic Circulation • Hepatic vein → IVC → Heart • Unbound vs Albumin-bound drug Only FREE drug is active 7–8. Tissue Distribution (Vd) • Capillary permeation to organs • Blood-Brain & Placental barriers Vd = Dose / C_0 (L or L/kg) 9. Target Site of Action • Receptors (GPCR, Ion channel) • Enzymes & Carrier Transporters Pharmacodynamic Effect (E_max, EC50) 10. Hepatic Biotransformation • Phase I (CYP450 Oxidation/Hydrolysis) • Phase II (Glucuronidation/Sulfation) Converts lipophilic drug → hydrophilic metabolite 11. Renal & Biliary Elimination • Nephron: Filtration + Secretion − Reabsorption • Biliary excretion & Enterohepatic recycling Total Clearance CL_tot = CL_renal + CL_hepatic 12. Excretion from the Body • Urine (Primary polar metabolite route) • Bile/Faeces, Expired Air, Sweat, Milk Elimination Half-Life t1/2 = (0.693 × Vd) / CL
svg-v339-01-adme-12-step-journey — 8.1 Complete 12-Step Journey of an Orally Administered Drug (ADME): Figure 8.1: The 12-step physiological journey of a typical orally administered solid dosage form through Liberation, Absorption, Distribution, Metabolism, and Excretion (LADME). Note: Parenteral (IV), sublingual, and inhalational routes bypass gastrointestinal absorption and/or hepatic first-pass metabolism.

12. Authoritative References, Regulatory Sources & Editorial Disclaimer

Primary Compendial & Guideline Reference: Indian Pharmacopoeia (IP 2026) • NLEM 2022 (MoHFW) • CDSCO Approved Prescribing Information

Official Verification Portals: Indian Pharmacopoeia Commission (IPC) & National Formulary of India (NFI) • Central Drugs Standard Control Organization (CDSCO) • Ministry of Health & Family Welfare — NLEM 2022 • NCBI Bookshelf / StatPearls Pharmacology Reference • DailyMed (US FDA Official Prescribing Reference)

Last Medically & Pharmaceutically Reviewed: 2026-11-10 • Verification Status: VERIFIED_EDUCATIONAL_CONTENT

Educational & Clinical Disclaimer: This reference profile is published solely for pharmacy education, academic study, and professional clinical reference. It does not substitute for patient-specific clinical judgement, qualified specialist oncology/medical supervision, or official CDSCO/IP prescribing information. Never self-medicate with prescription, Schedule H/H1/X, NDPS, or oncology medicines.