The currently recommended reduced-osmolarity oral rehydration salts (ORS) formulation used in India contains sodium in which concentration?

• A 111 mmol/L
• B 90 mmol/L
• C 75 mmol/L ✓
• D 60 mmol/L

Explanation

The reduced-osmolarity WHO ORS has a total osmolarity of 245 mmol/L with sodium 75 mmol/L, glucose 75 mmol/L, potassium 20 mmol/L, chloride 65 mmol/L and citrate 10 mmol/L. The older standard ORS contained 90 mmol/L sodium with total osmolarity 311 mmol/L and was replaced because the hypernatraemia and stool output were higher with the old formulation. Glucose absorption remains coupled to sodium via SGLT1.

Reference: Park's Textbook of Preventive and Social Medicine, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.