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Loperamide inappropriate use — GPhC CRA MCQ

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HardGastrointestinal TherapeuticsLoperamide inappropriate useGPhC CRA

A patient with a high-output ileostomy is prescribed 2 litres of St Mark’s electrolyte solution daily. Which quantities produce the standard formulation at the correct concentration?

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Correct answer: C — 40 g glucose, 5 g sodium bicarbonate and 7 g sodium chloride, made up to 2 L

The SPS recipe for one litre contains 20 g glucose, 2.5 g sodium bicarbonate and 3.5 g sodium chloride, made up to one litre with water. Doubling every ingredient gives 40 g, 5 g and 7 g respectively for two litres. Using the one-litre amounts in two litres halves the electrolyte concentration; the other choices selectively double or interchange an ingredient and do not reproduce the standard formulation.

Reference: SPS: using St Mark’s electrolyte solution. https://sps.nhs.uk/articles/using-st-marks-electrolyte-solution/