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MEDICINE MONOGRAPH CODE: [5.3] ID: TIP-MED-000071

Omeprazole

Active Ingredient / Scientific Identity: Omeprazole • Class: First-Generation Proton Pump Inhibitor (Racemic Benzimidazole Derivative)

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THE INDIAN PHARMACIST — Educational Reference Sheet
Profile: Omeprazole ([5.3] | ID: TIP-MED-000071) • Last Reviewed: 2026-11-10
Source URL: https://theindianpharmacist.com/medicine/5-3-omeprazole/
Generic / Entity NameOmeprazole ([5.3])
Verified Indian Brands / RefGeneric Compendial Entry (No Commercial Brand Claimed)
Pharmacological ClassFirst-Generation Proton Pump Inhibitor (Racemic Benzimidazole Derivative)
Available Dosage FormsEnteric-Coated Granule Capsules / Tablets: 10 mg, 20 mg, 40 mg; Oral Powder for Suspension (with Sodium Bicarb
Regulatory ClassificationSchedule H Prescription Drug (To be sold by retail on the prescription of a Registere
Key Warning & Review DateRenal: No dose adjustment needed; monitor for AIN in chronic use. Hepatic: Bioavailability increases to ~100% and half-life e
Reviewed: 2026-11-10
Safety Matrix:⚖️ Legal Status: Schedule H Prescription Drug (To be sold by retail o✔️ Standard Clinical Dispensing Precautions

1. Clinical & Scientific Overview

Omeprazole (TIP-MED-000071, Reference Code [5.3]) is classified under Gastrointestinal & Hepatobiliary Medicines (Ch 05) as a First-Generation Proton Pump Inhibitor (Racemic Benzimidazole Derivative). Within the Indian regulatory and compendial framework, it is governed under Schedule H Prescription Drug (To be sold by retail on the prescription of a Registered Medical Practitioner only — Drugs Rules 1945).

Verified Indian Market Examples / Compendial Status:
Representative Indian Market Examples (Edition 2.7 Ch 05 [5.3], p. 61): Omez (Dr. Reddy's), Ocid (Zydus), Lomac (Cipla), Nilsson; In FDC with Domperidone: Omez-D / Omez-DSR — Strengths & Dosage Forms: Enteric-Coated Granule Capsules / Tablets: 10 mg, 20 mg, 40 mg; Oral Powder for Suspension (with Sodium Bicarbonate): 20 mg
Representative Indian Market Examples (Edition 2.7 Ch 05 [5.3], p. 61): Omez (Dr. Reddy's), Ocid (Zydus), Lomac (Cipla), Nilsson; In FDC with Domperidone: Omez-D / Omez-DSR — Strengths & Dosage Forms: Enteric-Coated Granule Capsules / Tablets: 10 mg, 20 mg, 40 mg; Oral Powder for Suspension (with Sodium Bicarbonate): 20 mg
Dosage Forms & Available Strengths:
Enteric-Coated Granule Capsules / Tablets: 10 mg, 20 mg, 40 mg; Oral Powder for Suspension (with Sodium Bicarbonate): 20 mg
Routes: Oral / Parenteral / Topical as specified by formulation

3. Mechanism of Action & Pharmacodynamics

First-Generation Proton Pump Inhibitor (Racemic Benzimidazole Derivative) acting on target receptor/enzyme pathways in Gastrointestinal & Hepatobiliary Medicines (Ch 05): clinical efficacy is mediated via First-Generation Proton Pump Inhibitor (Racemic Benzimidazole Derivative) for Peptic ulcer disease; gastro-oesophageal reflux disease (GERD); dyspepsia; NSAID-associated ulcer prophylaxis; H. pylori triple/quadruple therapy..

4. Therapeutic Indications & Evidence-Supported Uses

  • Peptic ulcer disease
  • gastro-oesophageal reflux disease (GERD)
  • dyspepsia
  • NSAID-associated ulcer prophylaxis
  • pylori triple/quadruple therapy

🇮🇳 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: General Adult Reference: 20 mg once daily before breakfast (40 mg OD in refractory reflux ulceration; 20 mg BD in H. pylori eradication for 14 days). Follow physician prescription.

Administration & Meal Timing: Strictly 30 to 60 minutes BEFORE breakfast on an empty stomach. Do not chew or crush enteric-coated microgranules inside the capsule. | Once daily in the morning (or twice daily pre-breakfast and pre-dinner).

6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment

Absorption & Disposition:
Absorption, distribution, metabolism, and excretion follow class pharmacokinetic profile; verify patient renal/hepatic function.
Metabolism & Biotransformation:
Renal: No dose adjustment needed; monitor for AIN in chronic use. Hepatic: Bioavailability increases to ~100% and half-life extends to 3 hours in cirrhosis—limit dose to 10 mg–20 mg once daily in severe hepatic impairment.
Elimination & Renal Adjustment:
Renal: No dose adjustment needed; monitor for AIN in chronic use. Hepatic: Bioavailability increases to ~100% and half-life extends to 3 hours in cirrhosis—limit dose to 10 mg–20 mg once daily in severe hepatic impairment.
Hepatic Impairment Considerations:
Renal: No dose adjustment needed; monitor for AIN in chronic use. Hepatic: Bioavailability increases to ~100% and half-life extends to 3 hours in cirrhosis—limit dose to 10 mg–20 mg once daily in severe hepatic impairment.

7. Contraindications, Precautions & High-Risk Warnings

Contraindications & Red-Flag Precautions:
  • Exclude upper GI malignancy in elderly patients presenting with new-onset dyspepsia, anaemia, or weight loss. Long-term use (>8–12 weeks without high-risk indication) predisposes to micronutrient malabsorption, fractures, and enteric infections.

Key Clinical Precautions: Renal: No dose adjustment needed; monitor for AIN in chronic use. Hepatic: Bioavailability increases to ~100% and half-life extends to 3 hours in cirrhosis—limit dose to 10 mg–20 mg once daily in severe hepatic impairment.

8. Adverse Effects Profile

Common & Mechanism-Related Adverse Effects:
  • Headache, diarrhoea, constipation, abdominal bloating, nausea.
  • Acute interstitial nephritis, hypomagnesaemia, Vitamin B12 deficiency, C. difficile enterocolitis, osteoporotic fractures.
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

  • Strong CYP2C19 Inhibitor: Strictly avoid co-administration with Clopidogrel! Increases plasma levels of warfarin (R-warfarin), phenytoin, diazepam, escitalopram, cilostazol, and digoxin (~10%)
  • Reduces absorption of itraconazole, ketoconazole, oral iron, calcium carbonate, and mycophenolate mofetil
  • Delay in high-dose methotrexate elimination

10. Clinical Monitoring, Patient Counselling & Storage

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

Pharmacist Patient Counselling Points:

  • Patient Counselling Checklist: Swallow the Omez capsule whole 30 minutes before breakfast. Inform patients that taking Omez right after a heavy night meal as an 'instant antacid' does not work quickly because PPIs require several hours and meal activation—liquid antacids or alginates are used for immediate heartburn relief.
  • Meal & Clock Timing Instruction: Strictly 30 to 60 minutes BEFORE breakfast on an empty stomach. Do not chew or crush enteric-coated microgranules inside the capsule. (Once daily in the morning (or twice daily pre-breakfast and pre-dinner).)
  • Missed Dose Protocol: Take 30 minutes before the next meal if remembered the same day; never double the dose.
  • Geriatric Dispensing Pearl: Because omeprazole is widely dispensed in CGHS dispensaries, pharmacists must vigilantly check that elderly cardiac patients on Clopidogrel or Warfarin, or neurological patients on Phenytoin/Escitalopram, are switched to Pantoprazole to avoid CYP2C19 drug interactions.

Storage, Stability & Dispensing Safeguards: Store below 25°C–30°C in original moisture- and light-resistant packaging out of reach of children. Available forms: Enteric-Coated Granule Capsules / Tablets: 10 mg, 20 mg, 40 mg; Oral Powder for Suspension (with Sodium Bicarbonate): 20 mg

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 Pharmacist Desk Reference — Professional Edition 2.7 (2026–27) • Ch 05 [5.3] (p. 61)

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: HANDBOOK_SOURCE_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.

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Educational Reference Notice: This printout from THE INDIAN PHARMACIST (https://theindianpharmacist.com/medicine/5-3-omeprazole/, Last Reviewed: 2026-11-10) is an educational reference sheet for students and healthcare learners. It is NOT an official prescribing guideline or patient-specific treatment order.