1. Clinical & Scientific Overview
Oral Rehydration Salts (WHO Low-Osmolarity ORS 245 mOsm/L) (TIP-MED-000087, Reference Code [5.19]) is classified under
Gastrointestinal & Hepatobiliary Medicines (Ch 05) as a Physiological Glucose–Sodium Co-Transport Rehydration Solution (OTC | NLEM 2022).
Within the Indian regulatory and compendial framework, it is governed under Non-Schedule / Over-the-Counter Essential Life-Saving Formulation • NLEM 2022.
Representative Indian Market Examples (Edition 2.7 Ch 05 [5.19], p. 69): Electral (FDC), ORSL Powder, Walyte (Wallace), Prolyte (Cipla) — Strengths & Forms: Standard WHO 1-Litre Sachet (20.5 g): Anhydrous Glucose 13.5 g + NaCl 2.6 g + KCl 1.5 g + Trisodium Citrate 2.9 g (Na+ 75, Cl- 65, Glucose 75, K+ 20, Citrate 10 mmol/L = 245 mOsm/L); 200 mL Mini-Sachet (4.1 g)
Standard WHO 1-Litre Sachet (20.5 g): Anhydrous Glucose 13.5 g + NaCl 2.6 g + KCl 1.5 g + Trisodium Citrate 2.9 g (Na+ 75, Cl- 65, Glucose 75, K+ 20, Citrate 10 mmol/L = 245 mOsm/L); 200 mL Mini-Sachet (4.1 g)
3. Mechanism of Action & Pharmacodynamics
Physiological coupling via the apical Sodium-Glucose Linked Transporter 1 (SGLT1) on small intestinal villus enterocytes, which remains completely intact even during severe secretory diarrhoea (e.g., Vibrio cholerae toxin cAMP or ETEC heat-stable toxin cGMP hypersecretion). Equimolar (1:1) luminal glucose (75 mmol/L) and sodium (75 mmol/L) in a hypotonic 245 mOsm/L solution drive active cotransport of 2 Na+ + 1 Glucose across the brush border, creating an osmotic gradient that pulls water and electrolytes from the gut lumen into systemic circulation. Concurrent Zinc (20 mg/day x 14 days) inhibits cAMP-mediated chloride secretion, regenerates brush-border enterocytes, and prevents recurrent diarrhoea for 2–3 months.
4. Therapeutic Indications & Evidence-Supported Uses
- Prevention and treatment of dehydration due to acute watery diarrhoea (including cholera and rotavirus) across all age groups (WHO Plan A & Plan B) — co-administered with oral Zinc Sulphate for 14 days in children
5. Educational Dosage Context, Formulations & Administration
Educational Dosing & Regimen Summary: WHO Reduced-Osmolarity ORS Composition (per 1 Litre of clean drinking water): Sodium Chloride 2.6 g + Glucose (Anhydrous) 13.5 g + Potassium Chloride 1.5 g + Trisodium Citrate Dihydrate 2.9 g (Total = 20.5 g/L -> Na+ 75, Glucose 75, Cl- 65, K+ 20, Citrate 10 mmol/L = 245 mOsm/L). Paediatric Zinc Co-Therapy: 20 mg elemental Zinc once daily for 14 days (10 mg/day if age < 6 months).
Administration & Meal Timing: Oral (or via nasogastric tube in Plan B dehydration).
6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment
Absorption, distribution, metabolism, and excretion follow class pharmacokinetic profile; verify patient renal/hepatic function.
Safe.
Monitor fluid and potassium balance in oliguric acute kidney injury.
Safe.
7. Contraindications, Precautions & High-Risk Warnings
- Paralytic ileus, intestinal obstruction/perforation, or severe hemodynamic shock unable to drink (Plan C requires immediate IV Ringer's Lactate 100 mL/kg first, adding oral ORS as soon as the patient can drink)
Key Clinical Precautions: Safe.
8. Adverse Effects Profile
- Vomiting if drunk too rapidly (give slowly by spoon every 1–2 minutes)
- Puffy eyelids (periorbital oedema) indicate over-hydration — stop ORS temporarily and give plain water/breastmilk
- Metallic taste or mild nausea from Zinc Sulphate tablet (dissolve in a teaspoon of breastmilk or clean water)
- Monitor for severe hypersensitivity, organ toxicity, or dose-limiting adverse events.
9. Major Drug–Drug, Drug–Food & Drug–Herb Interactions
- High-sugar commercial fruit juices, carbonated colas, or sports drinks (>500–700 mOsm/L with minimal Na+): worsen osmotic diarrhoea and must NEVER be substituted for WHO 245 mOsm/L ORS
- Tetracyclines / Fluoroquinolones / Iron: Zinc chelates oral antibiotics and iron (separate by 2 hours)
10. Clinical Monitoring, Patient Counselling & Storage
Clinical & Laboratory Monitoring: Monitor clinical response, baseline renal/hepatic parameters, and relevant serum biomarkers.
Pharmacist Patient Counselling Points:
- Dissolve the entire 20.5 g WHO ORS packet in EXACTLY 1 Litre (1000 mL) of clean drinking water (or 4.1 g packet in 200 mL) — never boil the ORS solution after mixing, and never add extra sugar or salt.
- Discard any remaining reconstituted ORS solution after 24 hours and prepare a fresh batch.
- In children with diarrhoea, give the 20 mg Zinc dispersible tablet daily for the FULL 14 DAYS even after diarrhoea stops (reduces duration and prevents recurrence for 3 months).
Storage, Stability & Dispensing Safeguards: Store dry foil sachets below 30°C; discard prepared solution after 24 hours.
11. Visual Pharmacology & Mechanism Diagram (svg-v339-01-adme-12-step-journey)
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.