The reduced osmolarity Oral Rehydration Solution recommended by WHO for cholera and acute watery diarrhoea contains sodium at what concentration?

• A 50 mmol/L
• B 60 mmol/L
• C 75 mmol/L ✓
• D 90 mmol/L

Explanation

The WHO reduced osmolarity ORS contains sodium 75 mmol/L, chloride 65 mmol/L, potassium 20 mmol/L, citrate 10 mmol/L and glucose 75 mmol/L, giving a total osmolarity of 245 mmol/L. The earlier standard ORS had sodium 90 mmol/L and osmolarity 311, so option D represents the old formulation. The reduction was made to lower stool output and reduce the risk of hypernatraemia while maintaining efficacy in cholera.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.